Newsletter EnginSoft Year 9 n°4 -
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Flash Virtual Simulation creates more and more interest in diverse industrial fields and among the young; it is a driving force for innovation, for employment and creates opportunities for companies.
It is in this spirit that we are approaching the New Year at EnginSoft. We invite our readers to enjoy the articles in this Newsletter and to contact us with feedback and ideas for collaboration.
With the CAE Poster Award, EnginSoft fosters and promotes collaborations between industry and universities. At the International CAE Conference 2012, the Award was presented for the first time to six outstanding Young Researchers and businesses for their highly innovative work in the field of simulation. Many of our guests with whom I spoke at the Conference shared the enthusiasm for innovative research and to create new business, to realize visions, to make the most out of the enormous resources we have available in our network.
This issue presents contributions on the use of modeFRONTIER for the optimization of a boomerang shape, the analysis work performed for a frequency-reconfigurable microstrip antenna and the Particle Finite Element Method, PFEM. The latter is an effective numerical technique for multidisciplinary engineering problems which involve fluidsoil-structure interaction. Alenia Aermacchi, Politecnico di Torino and the Università del Salento inform us about ECS System Simulation for architecture and performance optimization. Further case studies cover the development work of Lovato Electric, the Feat Group, the Department of Information Engineering of University of Pisa as well as the use of the Grapheur technology for material selection.
While the year turns to an end, we are building on these foundations, on the opportunities and new activities we have created together with our customers and partners. Success is possible – together.
We introduce the RuBeeCOMP, the INTERCER2 and the “MUSIC” (which stands for: Multi-layer control & cognitive System to drive metal and plastic production line for Injected Components) Research Projects. Our Software Updates feature the latest ANSYS Workbench 14.5 release and SIMPACK, a multi-body simulation tool. We report from the TechNet Alliance Fall Meeting in Germany, the Round Table Meeting of companies from Venetia and offer a comprehensive review of the International CAE Conference to which EnginSoft had the great pleasure to welcome more than 700 attendees. We encourage our readers to download the Conference Proceedings and to look at the inspiring work of the awarded young researchers, the six Posters we also highlight in this Newsletter. Please stay tuned to the EnginSoft Training Program and Event Calendar. We hope to welcome many of you to our CAE courses and events in 2013 and beyond. EnginSoft and the Editorial Team wish you and your families a very happy, healthy and a prosperous New Year!
Stefano Odorizzi Editor in chief
Ing. Stefano Odorizzi EnginSoft CEO and President
Flash
4 - Newsletter EnginSoft Year 9 n°4
Sommario - Contents
CASE STUDIES
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Optimization of a Boomerang shape using modeFRONTIER The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Frequency-Reconfigurable Microstrip Antenna for Software Defined Radio ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot Grapheur for Material Selection Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura
RESEARCH & TECHNOLOGY TRANSFER
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Multidisciplinary Optimization for an IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform
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Meeting conclusivo del progetto 'RuBeeCOMP'
SOFTWARE UPDATES
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Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 Simulating Gear Pairs within SIMPACK
RESEARCH & TECHNOLOGY TRANSFER
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EnginSoft coordinates the new “MUSIC” European Project Modellazione e Progettazione Ottimale di Strutture Ceramiche EnginSoft ed il progetto INTERCER2
TRAINING
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Corsi di Addestramento Software 2013
EVENTS
56 58 59 66 68
International CAE Conference: like never before!
70 71
Trainer europei di ANSYS alla scuola EnginSoft
CAE Poster Award. A reward to the genius of young researchers EnginSoft sostiene le attività di Ricerca dell’Istituto Mario Negri di Milano Le reti d’impresa? Serve un cambio di mentalità CAE Conference 2012 welcomed Sponsors from Japan. Post-conference interviews Event Calendar
Contents
Newsletter EnginSoft Year 9 n°4 -
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Newsletter EnginSoft Year 9 n°4 - Winter 2012
PAGE 16 ECS SYSTEM SIMULATION OF AN ALENIA AIRCRAFT
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PAGE 24 HOW GEOMETRICAL DIMENSIONING & TOLERANCING INFLUENCES THE PERFORMANCES OF AN ELECTROMECHANICAL CONTACTOR
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RESPONSIBLE DIRECTOR Stefano Odorizzi - [email protected] PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA
Contents
Autorizzazione del Tribunale di Trento n° 1353 RS di data 2/4/2008
PAGE 41 MULTIDISCIPLINARY OPTIMIZATION FOR AN IEE 1902.1 “RUBEE” TAG
ESTECO www.esteco.com CONSORZIO TCN www.consorziotcn.it • www.improve.it
6 - Newsletter EnginSoft Year 9 n°4
Optimization of a Boomerang shape using modeFRONTIER A boomerang is a flying object apparently simple but particularly challenging for the complex physics modeling, since it should indeed involve: • six degrees of freedom body dynamics; • aerodynamics of rotational blades; • personal capabilities of the thrower; In this paper we show how the design optimization software modeFRONTIER, developed by ESTECO, can be employed for a non-standard problem consisting in the numerical simulation of the boomerang flight and the final optimization of its shape. The boomerang trajectory is obtained by means of a dynamic model integrated to a CFD analysis able to compute aerodynamic coefficients. To steer the complete optimization process modeFRONTIER is coupled to Catia v5 for the boomerang shape modification, to MATLAB for the dynamic simulation, and to Star-CCM+ for aerodynamic analysis. Moreover, dedicated RSM (Response Surfaces Methods) available in modeFRONTIER are used to extrapolate the aerodynamic coefficients as a function of the boomerang angle of incidence and velocity, as required by the dynamic model, allowing a reduced number of CFD analyses for each geometric configuration. Different design simulations are therefore automatically executed by modeFRONTIER, following a dedicated optimization strategy until the optimal geometry of the boomerang is found accordingly to the specified requirements, such as minimum energy for the launch and desired accuracy in returning. 1. Equations of the boomerang motion Considering that a boomerang spins fast, it is possible to write the so-calleds moothed boomerang equations in which the different quantities (velocities, angles, forces) are timeaveraged over a boomerang rotation:
where: Iz is the maximum boomerang principal moment of inertia; V is the velocity magnitude of the boomerang center
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of mass; m the boomerang mass; ψ is the angle of incidence of the boomerang; ϑ, φ, ψ are the Euler angles of a xyz reference system partially fixed on the boomerang (such that the boomerang center of mass is always placed in the xyz origin, the z axis is always directed as the maximum boomerang moment of inertia axis, namely normal to the section plane shown in Fig.3, and the projection of the boomerang center of mass velocity on the xy planes is directed as the –x axis); ωz the boomerang angular velocity around the z axis; Tx, Ty, Tz, Fx, Fy, Fz, are torque and force components in the xyz reference system, basically due to the interaction between the boomerang and the air and the gravity force. The gravity force can be expressed in the xyz reference system as:
The absolute position of the boomerang center of mass can be found as function of the previous parameters by:
The equations of motion can be integrated numerically (high order Runge-Kutta method) once the initial conditions are provided and the forces and torques are available at any time step. A candidate boomerang trajectory can therefore be simulated through the flowing steps: i) for a certain number of Ψ and U pairs (where U=V/ωza), with a distance between the boomerang center of mass and the farthest boomerang point from the center of mass) the corresponding not-dimensional values of F and T are computed by CFD simulations: a dimensional analysis can prove indeed that F and T depend only on Ψ and U for a given boomerang geometry and for a Reynolds number range typical of boomerang flights; ii) response surfaces for F(Ψ,U) and T(Ψ,U) are built; iii) equations of motion are integrated starting from given initial conditions and using the response surfaces computed previously to express forces and torques at any position and time step. The trajectory of the boomerang is affected by the initial conditions, namely by the way the boomerang is launched.
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Four launching parameters are considered (they will be automatically tuned for each candidate boomerang by the optimization methodology described in section 4): • V: initial boomerang translational velocity; • Spin: initial boomerang spin; • Aim: angle between the initial boomerang translational velocity and the horizontal plane; • Tilt: angle between the initial boomerang rotational plane and the vertical axis (0° tilt corresponds to a vertical boomerang plane of rotation). 2. Boomerang Parameterization The boomerang geometry chosen for the optimization will be the classical two arms “V” and “Ω” shape type. The most important parameters that affect the boomerang behavior are linked to the blades profile, the angle between the two arms and the dihedral of the arms. A total number of 9 input parameters has been defined. A. Blade profiles Changing the profile by playing with the angle of attack and cutting on the top of the leading and trailing edge can change a lot the lift provided by the arm. The lift in particular affects the turn capability of the Fig. 1 - Effect on blade profile of Bezier boomerang (precession control points effect). The arc blades are in general designed with a positive angle of attack; this helps the boomerang plane to lay down and to float in air. For the parametric boomerang geometry a flat bottom airfoil has been chosen. The blade profiles are built by a Bezier parametric curve, with 4 control points. The profile shape is modified by the changing vertical and horizontal position of the Bezier control points. In this way it is possible to change the angle of attack and the thickness of the blades (see Fig.1). The profiles of the leading and of the trailing arm are controlled by the same parameters, in order to reduce their total number. In particular the vertical position of the trailing arm is set as a fraction of the vertical position of the leading arm. B. Dihedral angle Boomerang arms usually have a positive dihedral angle of about 10°-15°; the dihedral affects both the lift and the lay down velocity of the rotation plane, keeping practically unchanged the mass of the boomerang. The boomerang parametric model is provided with the two parameters α and d that allow to change the dihedral by removing a small amount of material from the boomerang arms tips (Fig.2). The α parameter is basically the stabilizer’s angle of attack.
Fig. 2 - Leading and trailing edges; dihedral angle.
C. Angle between arms This angle usually ranges between 70° and 140°. In fact, this parameter has an important effect on the boomerang stability. The length of the arms is fixed to keep a constant overall size of the boomerang. 3. Aerodynamic forces computation details by CFD The CFD software employed is Star-CCM+. The approach we considered consists in using two reference systems - one external and inertial, the other fixed with respect to the boomerang and having its origin placed in the boomerang center of mass. Also, two domains and two grids are used: the first is spherical, having its origin placed in the boomerang center of mass and associated to the boomerang reference system; the second corresponds to an external parallelepiped shape associated to the external reference system. The internal spherical domain is provided with a rotation velocity around an axis normal to the boomerang plane and passing through the boomerang center of mass. The information exchange between the two domains is provided by an interface boundary that allows to interpolate the field values. In Star-CCM+, a polyhedral mesh with prisms layers at the boomerang walls is defined within the sphere around the boomerang and an hexahedral mesh is defined in the rest of the domain (Fig.3). The two-equations RANS SST (Shear Stress Transport) turbulent model, with wall functions, is chosen and a segregated solver with constant density is employed. A mesh size of about 2.5 millions of cells has been defined, this being a good tradeoff between Fig. 3 - Particular of a mesh section
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Fig. 4 - CFD results on different revolution frames
accuracy and computational efforts. Fig.4 shows the pressure field on a boomerang surface in different time steps during a rotation. It is possible to notice that the pressure force on each arm changes a lot during the rotation according to the relative position of the blades with respect to the translational velocity. At the end of the numeric simulation (for a given Ψ,U pair) the averaged forces and torques acting during the rotation are computed and then the corresponding F and T are available. 4. Process flow automation in modeFRONTIER The whole process aiming at evaluating and optimizing the performances of the boomerang has been completely automatized through the software modeFRONTIER. In this modular environment, the complete process flow is defined by the user, who can select among several available optimization algorithms, including Genetic and Evolutionary Algorithms, Game Strategies, Gradient-based Methodologies, Meta-Models and Robust Design Optimization.
Fig. 5 - modeFRONTIER main workflow
modeFRONTIER effectively automates the computation of the boomerang trajectory through the following steps: 1. modify the boomerang Catia model parameters; 2. obtain the updated geometry (stl file) from Catia and transfer it to Star-CCM+ execution module; 3. launch Star-CCM+ to build the computational mesh; 4. launch different Star-CCM+ simulations using the same mesh prepared as above varying U and Ψ parameters for an appropriate number of samples; for each U and Ψ pair the corresponding forces and torques F and T are obtained;
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5. use the set of simulations computed in iv) as training set to build in modeFRONTIER response surfaces to obtain F(Ψ,U) and T(Ψ,U) over the whole range of variation of Ψ,U 6. pass the response surfaces and the boomerang inertia data to a MATLAB script to compute the trajectory by integrating equations of motion using a 4th order RungeKutta method; 7. run an internal optimization for the given configuration to tune the four launching parameters (by minimizing the arrival distance); 8. the main multi-objective algorithm assesses how good the trajectory is with respect to specified objectives (total energy needed for the launch to be minimized) 9. the steps i)-viii) are repeated automatically by the algorithm until one or more optimal configurations are obtained. The modeFRONTIER workflow is shown in Fig.5. In particular, on the top we find the nodes (green subsystem) that define the range of variations of all the geometrical parameters, then the process flow (black line) starts with the interfaces to select the optimization algorithms and set their options, to continue with the CATIA direct interface that allows to automatically update the geometric model at the variation of the parameters, obtaining as results the updated Stl model, which is transferred to the following script node used to run Star-CCM+ to create the mesh for the proposed geometry. The mesh (.sim file) is then transferred to the following application node, which basically launches in batch mode another modeFRONTIER project file, running a set of CFD computations through Star-CCM+ on the same mesh varying U and Ψ parameters, as described at point iv) above. The output of the internal modeFRONTIER project is a Response Surface (RSM) or Metamodel, based on the available training set, able to extrapolate F(Ψ,U) and T(Ψ,U) over the whole range of variation of the two parameters (fig.6). The algorithm used for the RSM training is Kriging and the model is automatically exported as a C-script, which can be read by MATLAB. The last application node in the process flow is another modeFRONTIER project node, called “launch_parameters_tuning”. This node actually runs another optimization project in batch mode, using as input variables the four launch parameters described in section 1. The boomerang shape is fixed and the objective is defined by the minimization of the distance from the arrival position and the launching position. For this purpose, a fast monoobjective algorithm is used (Simplex) and the project just executes a MATLAB script through the corresponding direct interface for each set of launching parameters; basically the script drives a Runge-Kutta integration to compute the
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Fig. 6 - Response surfaces of boomerang aerodynamic forces
boomerang trajectory (retrieving the needed F(Ψ,U) and T(Ψ,U) values for each integration time step directly from the Response surface available for each boomerang geometry). The final outcome of the modeFRONTIER Batch node in the main process flow for each boomerang geometry is therefore its tuned trajectory, whose performances are to be optimized in the external loop. For this purpose, from this node the following outputs are extracted: • Range: this is the maximum distance reached by the boomerang during its flight; it has just been considered as a constraint in the optimization, to penalize configurations of too small range;; • Accuracy: this is the difference between the position from which the boomerang is launched and the position where the boomerang returns (optimized by the internal loop as described above for each boomerang candidate solution) • Energy: this is the energy (translational plus rotational) necessary to launch the boomerang, that is a quantity to be minimized (to reduce the effort for the thrower). 5. Optimization Strategy and Optimization Results Several tests were performed in order to find the proper number of simulations required to create enough accurate response surfaces. It has been found that a matrix of 12 points guarantees an error of approximation lower than 5% and this was the size of the training set finally selected. This means that each boomerang trajectory computation needs 12 CFD simulations. For this reason a classical multi-objective optimization algorithm that may require hundreds of designs evaluations is not practically feasible, therefore a different strategy, based on the Game Theory (Hierarchical Games), has been chosen. As indicated in the previous chapter, two different objectives (returning accuracy and launch global energy) have to be considered. Actually, any candidate solution is first optimized by the internal workflow in order to tune the launching parameters (follower player); then, the identified optimal solution is evaluated by the external optimization workflow which handles the energy objective minimization by changing properly the geometrical parameters (leader player). Note that for both the internal and external optimizer the same modeFRONTIER algorithm, Simplex, has
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been used due to its efficiency to solve single-objective problems in few iterations. Fig.7 reports the global results of the optimization process, in the space of the objectives and constraints considered. In particular the abscissa reports the launch energy (Joule), the ordinate indicates the range (meters), and the color of the bubbles reports the returning accuracy for each design (distance in meters). At the end of the process, one of the optimal boomerang configuration has been chosen and its geometry and trajectory are also reproduced in Fig.8. The energy required to launch the boomerang is 3.5 J, the ratio of rotational with total energy is only 7% that corresponds to an initial spin of about 4 Hz and to an initial translational velocity equal to 15 m/s; the tilt angle is 0°, while the aim is about 20°. This set should make the boomerang launch pretty easy, with a range of 14.5 m. In conclusion, this paper has described an automatic and efficient methodology for the multi-objective optimization of a boomerang shape, resulting an interesting benchmark and proof of concept to illustrate the multi-objective and multidisciplinary capabilities of the optimization environment modeFRONTIER. Rosario Russo, Alberto Clarich - ESTECO Spa Enrico Nobile, Carlo Poloni - Università di Trieste For more information: Francesco Franchini, EnginSoft [email protected]
Fig. 7 - Optimization results
Fig. 8 - Optimal boomerang configuration and trajectory
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10 - Newsletter EnginSoft Year 9 n°4
The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Introduction The analysis of problems involving the interaction of fluids, soil/rocks and structures is relevant in many areas of engineering. Examples are common in the study of landslides and their effect on reservoirs and adjacent structures, off-shore and harbour structures under large waves, constructions hit by floods and tsunamis, soil erosion and stability of rockfill dams in overspill situations, excavation and drilling problems in civil and petroleum engineering, etc. The author and his group have developed in previous works a particular class of Lagrangian formulation for solving problems involving complex interactions between (free surface) fluids and solids. The so-called particle finite element method (PFEM, www.cimne.com/pfem), treats the mesh nodes in the fluid and solid domains as particles which can freely move and even separate from the main fluid domain representing, for instance, the effect of water drops. A mesh connects the nodes discretizing the domain where the governing equations are solved using a stabilized FEM. An advantage of the Lagrangian formulation used in PFEM is that the non-linear and non symmetric convective terms disappear from the fluid equations. The difficulty is however transferred to the problem of adequately (and efficiently) moving the mesh nodes. In the next section the key ideas of the PFEM are outlined. Next the basic equations for a general continuum using a Lagrangian description and the formulation are schematically presented. We present several examples of application of the PFEM to solve multidisciplinary FSSI problems such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the study of a landslide falling into a reservoir, the sinking of ships and the collision of ships with ice blocks.
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The basis of the particle finite element method In the PFEM both the fluid and the solid domains are modelled using an updated Lagrangian formulation. That is, all variables are assumed to be known in the current configuration at time t. The new set of variables in both domains is sought for in the next or updated configuration at time t + Δt. The finite element method (FEM) is used to solve the equations of continuum mechanics for each of the subdomains. Hence a mesh discretizing these domains must be generated in order to solve the governing equations for each subdomain in the standard FEM fashion. The quality of the numerical solution depends on the discretization chosen as in the standard FEM. Adaptive mesh refinement techniques can be used to improve the solution.
Fig. 1 - Scheme of a typical solution with PFEM. Sequence of steps for moving a “cloud” of nodes representing a domain containing a fluid and a solid part from time n (t=tn) to time n+2 (t=tn + 2Δt)
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For clarity purposes we will define the collection or cloud of nodes (C) pertaining to the analysis domain (V) containing the fluid and solid subdomains and the mesh (M) discretizing both domains. A typical solution with the PFEM involves the following steps. 1. The starting point at each time step is the cloud of points in the fluid and solid domains. For instance nC denotes the cloud at time t = tn (Figure 1). 2. Identify the boundaries for both the fluid and solid domains defining the analysis domain nV in the fluid and the solid. This is an essential step as some boundaries (such as the free surface in fluids) may be severely distorted during the solution, including separation and reentering of nodes. The Alpha Shape method is used for the boundary definition. 3. Discretize the fluid and solid domains with a finite element mesh. nM We use an effect mesh generation scheme based on the extended Delaunay tesselation. 4. Solve the coupled Lagrangian equations of motion for the overall continuum. Compute the state variables in at the next (updated) configuration for t + Δt: velocities, pressure and viscous stresses in the fluid and displacements, stresses and strains in the solid. 5. Move the mesh nodes to a new position n n+1C where n+1 denotes the time tn + Δt, in terms of the time increment size. This step is typically a consequence of the solution process of step 4. 6. Go back to step 1 and repeat the solution for the next time step to obtain n+2C (Figure 1). We emphasize that the key differences between the PFEM and the classical FEM are the remeshing technique and the identification of the domain boundary at each time step. Generation of a new mesh A key point for the success of the PFEM is the fast regeneration of a mesh at every time step on the basis of the position of the nodes in the space domain. In our work the mesh is generated using the so-called extended Delaunay tesselation (EDT). As a general rule for large 3D problems meshing consumes around 15% of the total CPU time per time step, while the solution of
Fig. 2 - Modelling of contact conditions at a solid-solid interface with the PFEM
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the equations (with typically 3 iterations per time step) and the system assembly consume approximately 70% and 15% of the CPU time per time step, respectively. These figures refer to analyses in a single processor Pentium IV PC and prove that the generation of the mesh has an acceptable cost in the PFEM. Indeed considerable speed can be gained using parallel computing techniques. Identification of boundary surfaces One of the main tasks in the PFEM is the correct definition of the boundary domain. Boundary nodes are sometimes explicitly identified. In other cases, the total set of nodes is the only information available and the algorithm must recognize the boundary nodes (Figure 2). In our work we use a Delaunay partition for recognizing boundary nodes and, hence, boundary surfaces. This is performed by using the so-called Alpha Shape method. This method also allows one to identify isolated fluid particles outside the main fluid domain. These particles are treated as part of the external boundary where the pressure is fixed to the atmospheric value. We recall that each particle is a material point characterized by the density of the solid or fluid domain to which it belongs. The mass lost when a boundary element is eliminated due to departure of a node from the analysis domain containing a fluid is regained when the node falls down and a new boundary element is created by the Alpha Shape algorithm. The boundary recognition method is useful for detecting contact conditions between the fluid domain and a boundary, as well as between different solids as detailed in the next section. Treatment of contact conditions in the PFEM Known velocities at boundaries in the PFEM are prescribed in strong form to the boundary nodes. These nodes might belong to fixed external boundaries or to moving boundaries. Contact between fluid particles and fixed boundaries is accounted for by the incompressibility condition which naturally prevents fluid nodes to penetrate into the solid boundaries. The contact between two solid interfaces is treated by introducing a layer of contact elements between the two interacting solid interfaces. This layer is automatically created during the mesh generation step by prescribing a minimum distance (hc) between two solid boundaries. If the distance exceeds the minimum value (hc) then the generated elements are treated as fluid elements. Otherwise the elements are treated as contact elements where a relationship between the tangential and normal forces and the corresponding displacement is introduced (Figure 2). This algorithm allows us to identify and model complex frictional contact conditions between two or more interacting bodies moving in water in an extremely simple manner. The algorithm can also be used effectively to model frictional contact conditions between rigid or elastic solids in structural mechanics applications. Modeling of bed erosion Prediction of bed erosion and sediment transport in open channel flows are important tasks in river and environmental
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12 - Newsletter EnginSoft Year 9 n°4 engineering. Bed erosion can lead to instabilities of the river basin slopes. It can also undermine the foundation of bridge piles thereby favouring structural failure. Modeling of bed erosion is also relevant for predicting the evolution of surface material dragged in earth dams in overspill situations. Bed erosion is one of the main causes of environmental damage in floods. In a recent work we have proposed an extension of the PFEM to model bed erosion. The erosion model is based on detaching elements belonging to the bed surface in terms of the frictional work at the surface originated by the shear stresses in the fluid. The resulting erosion model resembles Archard law typically used for modeling abrasive wear in surfaces under frictional contact conditions. Sediment deposition can be modeled by an inverse process. Hence, a suspended node adjacent to the bed surface with a velocity below a threshold value is attached to the bed surface.
Fig. 5 - Erosion of a soil mass due to sea waves and the subsequent falling into the sea of an adjacent lorry
Fig. 6 - Simulation of landslide falling on constructions using PFEM
Fig. 3 - Breaking waves on breakwater slopes containing reinforced concrete blocks
Examples Impact of sea waves on piers and breakwaters Figure 3 shows the analysis of the effect of breaking waves on two different sites of a breakwater containing reinforced concrete blocks (each one of 4x4x4 mts). The figures correspond to the study of Langosteira harbour in A Coruña, Spain using PFEM. Soil erosion problems Figure 4a shows the capacity of the PFEM for modelling soil erosion, sediment transport and material deposition in a river bed. The soil particles are first detached from the bed surface under the action of the jet stream. Then they are transported by the flow and eventually fall down due to gravity forces into the bed surface at a downstream point. Figure 4b shows the progressive erosion of the unprotected part of a breakwater slope in the Langosteira harbour in A Coruña, Spain. The non protected upper shoulder zone is progressively eroded under the sea waves. Falling of a lorry into the sea by erosion of the road slope due to sea waves Figure 5 shows a representative example of the progressive
Fig. 4 - (a) Erosion, transport and deposition of soil particles at a river bed due to an impacting jet stream (b) Erosion of an unprotected shoulder of a breakwater due to sea waves
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Fig. 7 - Lituya Bay landslide. Left: Geometry for the simulation. Right: Landslide direction and maximum wave level
erosion of a soil mass adjacent to the shore due to sea waves and the subsequent falling into the sea of a 2D object representing the section of a lorry. The object has been modeled as a rigid solid. This example and the previous ones, although still quite simple and schematic, show the possibilities of the
Fig. 8 - Lituya Bay landslide. Evolution of the landslide into the reservoir obtained with the PFEM. Maximum level of generated wave (551 mts) in the north slope
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height observed was 208 mts, while the PFEM result (not shown here) was 195 mts (6% error). Simulation of sinking of ships The PFEM can be effectively applied for simulating the sinking of ships under a variety of scenarios. Figure 9 shows images of the 2D simulation of the sinking of a cargo vessel induced by a breach in the bow region. Figure 10 displays a 3D simulation of the skinking of a simple fisherman boat induced by a hole in the side of the hull. These examples evidence the potential of PFEM for the study of the sinking of ships. Colision of boat with ice blocks Figures 11 shows an example of the application of PFEM to the study of the collision of a ship with floating ice blocks. The boat and the ice blocks have been modelled as rigid bodies in this example. Indeed, the deformation of the ship structure due to the ice-ship interaction forces can be accounted for in the analysis.
Fig. 9 - 2D simulation of the sinking of a cargo vessel due to a breach in the bow region. (a) Water streamline at different times. (b) Water velocity pattern at different times during sinking
PFEM for modeling complex FSSI problems involving soil erosion, free surface waves and rigid/deformable structures.
Conclusions The particle finite element method (PFEM) is a promising numerical technique for solving fluid-soil-structure interaction (FSSI) problems involving large motion of fluid and solid particles, surface waves, water splashing, frictional contact situations between fluid-solid and solid-solid interfaces and bed erosion, among other complex phenomena. The success of the PFEM lies in the accurate and efficient solution of the equations of an incompressible continuum using an updated Lagrangian formulation and a stabilized finite element method allowing the use of low order elements with equal order interpolation for all the variables. Other essential solution ingredients are the efficient regeneration of the finite element mesh, the identification of the boundary nodes using the Alpha-Shape technique and the simple algorithm to treat frictional contact conditions and erosion/wear at fluid-solid and solid-solid interfaces via mesh generation. The examples presented have shown the potential of the PFEM for solving a wide class of practical FSSI problems in engineering.
Modelling of landslides The PFEM is particularly suited for modelling landslide motion and its interaction with structures and the environment. Figure 6 shows a simulation using PFEM of a soil mass representing a landslide falling on four constructions modelled as rigid body solids. A case of much interest is when a landslide occurs in the vicinity of a reservoir. The fall of debris material into the reservoir typically induces large waves that can overtop the dam originating an unexpected flooding that can cause severe damage to the constructions and population in the downstream area. We present some results of the 3D analysis of the landslide produced in Lituya Bay (Alaska) on July 9th 1958 (Figure 7). The landslide was originated by an earthquake and Eugenio Oñate mobilized 90 millions tons of rocks that fell on the bay International Center for Numerical Methods originating a large wave that reached a hight on the opposed in Engineering (CIMNE), Spain slope of 524 mts. Figure 8 shows images of the simulation of the Universitat Politècnica de Catalunya (UPC), Spain Lituya Bay landslide with PFEM. PFEM results have been compared with observed values of the maximum water level in the north hill adjacent to the reservoir. The maximum water level in this hill obtained with PFEM was 551 mts. Fig. 10 - 3D simulation of the sinking of a boat induced by a hole in the side of the hull This is 5% higher than the value of 524 mts. observed experimentally. The maximum height location differs in 300 mts from the observed value. In the south slope the maximum water Fig. 11 - 3D simulation of a boat colliding with five ice blocks
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14 - Newsletter EnginSoft Year 9 n°4
Frequency-Reconfigurable Microstrip Antenna for Software-Defined Radio The increasing demand for portable devices with wireless connectivity within a wide frequency spectrum presents an ambitious challenge for the designer of the RF front-end who has to manage different wireless standards (GSM, UMTS, WiMAX, WiFi, Bluetooth, LTE). Covering several frequency bands simultaneously with a single antenna can be a very demanding task, which is why the employment of many different antennas integrated in the device and the use of multiband or broadband antennas might be a feasible solution for the problem. The use of different antennas implies an increase of the overall cost and space requirements. Broadband antennas transmit and receive signals within a large bandwidth but they may suffer an unbearable deterioration of the signal to noise ratio and thus a reduction of the overall efficiency of the system. Moreover, the electromagnetic spectrum is a shared resource that is more and more congested with the increasing number of users of wireless devices and the further exploitation of the available frequencies by other services poses practical and regulatory difficulties. To cope with this problem, the employment of an unused part of the spectrum or the opportunistic and temporary use of a shared portion may offer new resources.
upgrade, without changing the controlled hardware. This ambitious objective imposes strict requirements to the capabilities of the device radio front-end especially in terms of the requested frequency agility necessary for the smart and dynamic adaptation to the wireless environment. In particular, severe constraints are placed on critical components such as filters, matching networks and antennas. The SDR architecture requires a reconfigurable antenna which is able to modify one, or a combination, of its fundamental radiation properties depending on the adopted scheme [6]. A radiating device can exhibit a frequency agility, which allows to set its instant working frequency, a change in pattern shape, or an alteration of the electric field polarization. The reconfiguration is obtained by adjusting the path of currents on the antenna or even by altering the geometry of the radiating device. The three aforementioned degrees of reconfigurability can be realized by recurring to different technologies among which electrical RF switches such as PIN diodes and varactors, photoconductive elements or MEMS. Different kinds of antennas have been proposed for the enhancement of the SDR radio frontend including PIFAs, monopoles and patches.
The Cognitive Radio (CR) concept has been proposed as a Within this framework, we have recently developed a solution since the related CR radio network is able to evaluate reconfigurable microstrip patch antenna by using PIN diodes the instant occupancy of spectrum and decides on this basis as RF switches whose biasing network is how to allocate services on temporarily software-controlled via a PIC unoccupied parts of the EM spectrum. microcontroller. The microstrip patch This recent paradigm of communication antenna has been chosen for its low allows an efficient spectrum usage but profile, robustness and easy also poses some challenges, with regard manufacturing. The aim is to obtain an to hardware and software, which have antenna with a reconfigurable motivated the rise of the Software frequency response between 850 MHz Defined Radio (SDR) concept during the and 3.5 GHz by simply changing the last years. A device based on SDR is an state of the RF switches. After a integrated system which must exhibit preliminary optimization study based on extreme hardware performance to the cavity model of the patch antenna, support the necessary software-based we have considered the configuration signal processing and guarantee the shown in Fig. 1 in which five PIN diodes desired flexibility. The final goal is Fig. 1 - Top view of the frequency-reconfigurable microstrip patch antenna. The continuous circles are able to guarantee a proper sweep of therefore to implement most of the radio indicate group#1 whereas dashed circles designate the working frequency. The positions of system in software, easy to update or group#2.
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the RF switches have been chosen by inspecting the path of the currents on the patch surface to individuate the most suitable placement of the diodes to guarantee the current flow. The overall size of the patch antenna is 84 mm × 70 mm. It is worthwhile to mention that the size of each element in the antenna and the position of the PIN diodes were chosen under two imposed constraints. First of all, in order to reduce the complexity of the design, we aimed at a configuration where all the RF-switch biasing lines had to be placed on the top layer of the antenna substrate, avoiding any cut in the ground plane. Next, we also searched for a solution without any matching network thus requiring in each RF-switch state an impedance close to the 50 Ohm of the feeding line. Two shorting pins with a 1.0-mm-diameter were inserted as illustrated in Fig. 1, the former in one of the outer sections and the latter in the inner element. To obtain a correct evaluation of the antenna behavior, the diodes have been considered by using their circuit model in the Ansoft HFSS simulations (Fig. 2) instead of substituting them as an open circuit in the 'Off' case and as a short circuit when in 'On' state. The employed PIN diode is an Avago HSMP-4890 which presents Rs = 2.5 Ohm, L = 1 nH, CT = 0.3 pF and RP in the order of KOhm. The PIN diodes were placed by using silver conductive epoxy to avoid overheating of the device. Fig. 2 - PIN diode circuit In our design the five PIN diodes model for the 'On' state (a) have been divided into two groups and 'Off' state (b). (continuous and dashed circles as shown in Fig.1) thus providing four possible configurations. Each group allows current to flow when the diodes are in 'On' state whereas the propagation of the RF signal is interrupted when they are set to 'Off' state. The biasing network comprises two lines on the top of the dielectric substrate which connect each of the outer sections of the patch to the DC source. A RF block is necessary to isolate the RF and DC source on these biasing lines. Moreover, the inner element of the antenna and the other one inside the simil-loop element are connected to the ground plane by using the 1.0-mm-diameter via. This configuration allows modifying the state of the two RF-switch groups by simply changing the voltage between the ground plane and the two lines connected to each antenna side. In order to change on demand the instantaneous frequency, we have programmed a PIC16F688 flash microcontroller to switch among the four possible configurations described above and we have Fig. 3 - The antenna configuration is completely software-controlled by using the directly connected the PC which operates on the PIC microcontroller prototype board to a to change the state of PIN diodes.
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Fig. 4 - Frequency response of the antenna when PIN diodes belonging to group#2 are in 'On' state and others are in 'Off' state.
laptop through an USB interface (Fig. 3). Therefore the activation and deactivation of the RF switches is performed by a microcontroller which can change the working frequency on the basis of the information collected by another antenna (sensing antenna) which is scouting the available frequency slots, as proposed in the CR paradigm. A comparison between the simulated and measured S11 parameters for the configuration with group#1 in OFF state and group#2 in ON state is reported in Fig.4 and the agreement is satisfactory except for some frequency shifts which could be attributed to discrete component tolerances and soldering effects.
Fig. 5 - Comparison between the simulated (continuous line) and measured (dashed line with triangles) radiation patterns at 850 MHz: φ = 0 deg., φ = 90 deg.
The simulated and measured patterns on the xz (φ = 0) and yz (φ = 90) planes are reported in Fig. 5. From the inspection of the results it is apparent that there is no significant distortion of the antenna pattern caused by the PIC microcontroller and the biasing lines. Ing. Simone Genovesi, Prof. Agostino Monorchio Microwave and Radiation Lab., Dip. Ingegneria dell'Informazione (www.mrlab.it) Università di Pisa For more information, please contact: [email protected][email protected]
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ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design In today’s aircraft thermal design, we can observe a trend towards electronics systems integration characterized by higher heat densities and a more frequent use of composite primary structures. All these factors require robust thermal management and thermal architecture design already at the preliminary design stages. The thermal architecture will have to be developed in order to mitigate thermal risks for temperature-sensitive equipment as well as to limit the aircraft systems overdesign. The improvement and optimization of the thermal architecture is regarded as one of the key success factors for future aircraft developments. It requires a complete pyramid of simulation tasks to be set up, from the individual equipment to aircraft section simulation, to the global aircraft thermal analysis. Many difficulties arise from this simulation framework due to the variety of physical models, partners, techniques and tools used at each level of the pyramid.
In this context, the aim of this paper is to describe an Environmental Control System design approach as applied in Alenia Aermacchi. The main technical challenges addressed in this paper are: • Air conditioning pack architecture design • Air distribution line design and trade-off study, • Multidisciplinary optimization of the air distribution system components • A/C cabin thermal environment evaluation and occupants’ thermal comfort. Background The air conditioning system is designed in such a way that it maintains the air within the pressurized fuselage
Fig. 2 - Thermal aircraft schematic
Fig. 1 - A/C air conditioning pack and air distribution system
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Table 1 - Electrical equipment dissipated power
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compartment at the required level of pressure, temperature, flow rate and purity. The air is supplied to the system from the engine compressor, the hot compressed air is cooled and conditioned in the air conditioning pack before being distributed to the various compartments through the air conditioning system (see Figure 1).
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As shown in Figure 4, the standard air condition pack architecture has been considered. Figure 4 illustrates also the mono-dimensional model built in LMS Amesim. The heat exchanger mono-dimensional model (low fidelity model) has been validated by comparing its results with CFD model results (high fidelity model). In Figure 5, we can see the validation analysis results.
Accordingly, in order to guarantee a comfortable A/C cabin environment, it is necessary to design and optimize the air conditioning pack and air distribution system. Air conditioning pack architecture design Requirements This study focuses on the following requirements: • A/C schematic configuration (see Figure). • Thermo-acoustic insulation U factor. • Electrical equipment dissipated power (see Table 1). • Temperature requirements for cabin/ cockpit. • Environmental envelope (see Figure 3). • The certification and performance requirements of ECS are reported below: o Minimum fresh flow per passenger: 0.55 lb/min. o Minimum fresh flow per crew member: 10 cfm. o Minimum fresh flow per galley 15 cfm. o Maximum ratio recirculation / total flow 0.4. o Maximum fresh flow per passenger/crew member for single pack operations 0.4. o Cabin stabilized temperature between 21°C -27°C. o Cockpit stabilized temperature between 21°C-27°C. Methodology The design of the air conditioning pack architecture has been reached through the following steps: • Definition of air conditioning pack monodimensional model. • Definition and validation of heat exchanger mono-dimensional model. • Definition of A/C cabin thermal monodimensional model. • Optimization of heat exchanger design, in order to meet certification and performance requirements.
Fig. 3 - Environmental envelope
Fig. 4 - ECS pack 1D- model
Fig. 5 - Heat exchanger size
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18 - Newsletter EnginSoft Year 9 n°4 • Steady state, cruise cold day (40 kft, -70 °C, Mach 0.85, 20% passengers) The heat exchanger has been defined in terms of its geometrical characteristics and number of plates. As shown in Figure 7, the analysis results confirm the compliance of the air conditioning pack architecture with the certification and performance requirements.
Fig. 6 - A/C mono-dimensional thermal model
Air distribution line design and trade-off study In order to determine the air conditioning pack architecture, the second step focused on the definition of the air distribution system. The latter depends on the following aspects: • Performance in terms of pressure losses. • Integration in aircraft. • Reliability and maintainability. Two different architectures have been analyzed. The first one (Architecture A) shown in Figure 8 is a parallel architecture composed of an underfloor line and a low pressure air distribution line that allow to distribute the airflow coming from the mixing chamber in parallel through the risers.
Fig. 7 - Performance of air conditioning pack
Fig. 8 - Air distribution system CAD model – Architecture A
Fig. 10 - Mono-dimensional model Architecture A.
Fig. 9 - Air distribution system CAD model – Architecture B
In order to design the air cycle machine and heat exchanger, the cabin aircraft mono-dimensional thermal model shown in Figure 6 has been built. It allowed to evaluate the cabin thermal environment and hence the compliance with varying pack performance depending on the heat exchanger design. The operating conditions analysed have been: • Steady state, ground hot day (ISA+25, 100% passengers) • Steady state, ground cold day (ISA-55, 20% passengers) • Steady state, cruise hot day (40 kft, -35°C, Mach 0.85, 100% passengers)
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Fig. 11 - Mono-dimensional modelArchitecture B.
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As boundary conditions we assumed the data reported below in various flight conditions, then the steady state analysis has been carried out: • Temperature, air flow, pressure and humidity coming from the air conditioning pack. • External conditions in terms of temperature. • Equipment and light heat load. • Passengers heat load. Figure 12 shows the analysis results in terms of pressure drop vs mass flow curve. In particular, the results highlight that the air distribution system pressure losses of Architecture A are higher than those of Architecture B.
Fig. 12 - Pressure loss vs massflow curves
The second one (Architecture B) shown in Figure 9 is a sequential architecture where the under floor is much limited, and the cabin air distribution system is developed above the floor. Starting from the CAD model shown above, a monodimensional model for each architecture has been built in LMS Amesim (see Figures 10 and 11). The mono-dimensional models are composed of the following parts: • Connection with air conditioning pack mono-dimensional model. • Cockpit line • Cabin line • Simplified A/C thermal model as thermal node. • Internal macro that allows to simulate the physiology of the passengers in terms of heat load and humidity released.
Fig. 13 - Technical performance measure
A comparison analysis has been performed by means of a Technical Performance Measure (TPM) methodology. First, all of the key requirements (performance, system integration in the aircraft, RMT) have been defined, categorized and weighted according to their degree of importance. Key factors and preferences have been established on the basis of Alenia’s experiences. Normalized weights of 0-1 range have been assigned as per the above to each key requirement. Then, each requirement has been split into sub-requirements, as follows: • Performance: o Pressure loss. • System Integration in the aircraft: o Influence on cabin noise; o Weight; o Ease of installation. • RMT o Reliability; o Maintainability. Each sub-requirement has been weighted according to its degree of importance compared to the others. Then, each weight has been normalized in absolute terms, in accordance with the key requirements. Also a score has been assigned to each sub-requirement, as follows: • 1 = VERY POOR: the proposed solution does not meet the system’s requirements; • 2 = POOR: the proposed solution does not meet the system’s requirements but the requirement deviation is acceptable;
Fig. 14 - CAD model for Outlet
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20 - Newsletter EnginSoft Year 9 n°4
Fig. 15 - Parametric model
• 3 = ACCEPTABLE: the proposed solution meets the system’s requirements, but with some risks. • 4= GOOD: the proposed solution meets the system’s requirements. Subsequently, attributes, weights and scores have been allocated, the quantitative frame which builds a rational evaluation has been defined, calculating the relevant weighted score for each sub-requirement. Figure 13 shows details of the TPM comparison analysis results. Following the outcome of the TPM approach, the results of architecture A of the air distribution system are preferred. Multidisciplinary optimization of air distribution system components The shape optimization of the air vent outlet has been carried out through the following phases: 1. Mesh accuracy study 2. Input sensitivity study 3. Design of Experiment (DOE) Analysis 4. Optimization 5. Automatic updating of the party in the product Design specifications Based on the flow of incoming air assigned to the maximum operative mass flow rate, the shape of the air vent outlet has been optimized (Figure 14) with the objective of minimizing pressure losses and noise levels. To achieve these goals, the geometry for the surface connection between the inlet and outlet of the nozzle has been parameterized.
Among the geometric parameters that were evaluated for the optimization is the angle Alpha; it is important to mention that this angle is formed by the axis coming from the centre of the inlet and the centre of the outlet, it changes the direction in which the air flow enters the cabin. Parameterization For the parameterization 6 points have been identified; these 6 points are located on the intersection of a virtual plane perpendicular to the line joining the centres of the inlet and the exit outlet. The 6 splines in Figure 15 have been initially identified as points A, B, C, D, E, F. As these point change their locations, the area of the opening will be adapted for the purpose of the optimization. Based on this configuration and by changing the location of the points, it becomes possible to update the area of the opening and in this way to modify the purpose of the optimization. modeFRONTIER Model In the modeFRONTIER model the geometric inputs are held constant while varying only the parametric data for the CAE model. The process flow consists of three blocks: 1. CATIA process: it opens the file CatiaV5 CATPart geometry of the nozzle, then it converts files into IGS and sends them to the next process. 2. STAR Process: StarCCM+ runs a mesh with Base Size Length which is assigned to the CAE_Input, then it automatically performs the calculations. It estimates the time taken (CPU_Time), and sends the simulation file (SIMfile) for the next process. 3. Process PostPRO: StarCCM+ checks for the simulation file, and if there are further calculations to determine the pressure and noise levels, in particular, according to the PostPRO_Input, a visual representation is saved in a jpeg file containing the pressure, the speed or noise level, as well as images of the mesh and the graph of the residue. The variables monitored are CPU processing time in seconds, CPU_Time, and total pressures in Pascal in and out of the nozzle: p_in p_out respectively.
Fig. 16 - modeFRONTIER model for shape and noise optimization of the outlets
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Design Of Experiment (DOE) Analysis In modeFRONTIER (whose workflow is shown in Figure 16) a DOE analysis has been performed taking into account the 3 free parameters dx_CF, dy_AB, and dy_DE, while, dx_AB, dx_DE, and dy_CF remain constant or the abscissas of points A, B, D and E. The ordinates of tpoints C and F remain stationary as assigned by the geometry.
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Table 2 - Table of results for optimal pressure and optimal noise reduction based on DOE
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Table 3 - MDO results based on the NSGA-II analysis
The range of variations of the free parametersis as follows: • dx_CF varies from -5 mm to +25 mm in steps of 10 mm (5 mm, +5 mm, +15 mm, +25 mm) • dy_AB ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) • dy_DE ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) The challenge of the optimization has been a multidisciplinary and multi-objective problem: the disciplines involved have been fluid dynamics and acoustics, the objectives were minimizing the pressure drop (p_in - p_out) and minimizing the level of noise emitted from outlets and walls.
Fig. 18 - Parallel Coordinates Chart optimization
Fig. 18 - Acoustic analysis for the outlet Fig. 17 - Parallel Coordinates Diagram for the restriction of the domain space of pressure loss and noise
Results A 4 level full factorial DOE has been carried out on the 3 variables, which means that 64 configurations have been tested (43 = 64 experiments). Following are the results which represent a significant improvement to the previously adopted design. The minimum pressure drop (corresponding to the configuration process number 9) and the minimum sound level (corresponding to the configuration process number 59) are shown in Table 2. From the table, it becomes clear that the two objectives cannot be achieved simultaneously, as the minimum pressure drop is far from the minimum level of noise produced by the walls (Table 2). Therefore, the analysis moved on to a Multidisciplinary Design Optimization MDO. Outlet MDO To refine the research of the investigation it has been decided to filter the results by imposing the limits of acceptance for the pressure drop in relation to the level of noise emitted from the walls. The filtering action narrowed the range of variations. This effect is shown in the filters operating diagrams in Figure 17, where the parallel coordinates were
Fig. 19 - Outlet CFD analysis for pressure drop
reduced to a range of 3 to 28 dB noise levels and a maximum pressure drop of 4 Pa. As before, the three parameters that vary have been dx_CF, and dy_AB dy_DE, while the other 3 parameters, dx_AB, and dx_DE dy_CF, remain constant, or the abscissas of points A, B, D and E. • dx_CF ranges from +12.5 mm to +25.0 mm in steps of 2.5 mm • dy_AB varies from -2.5 mm to +12.5 mm in steps of 2.5 mm • dy_DE varies from -2.5 mm to +12.5 mm in steps of 2.5 mm The optimization has been performed by implementing the Non-dominated Sorting Genetic Algorithm II (NSGA-II) with
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22 - Newsletter EnginSoft Year 9 n°4 treatment) of roughly 2 million cells has been constructed. • Boundary condition definition: all operating conditions. In this paper, we show the results of the boundary conditions, they are reported in Figure 20. Furthermore, an internal macro has been developed and embedded into StarCCM+ in order to simulate the physiology of the passenger in terms of heat load and % of humidity released. • Physics model: steady state, KEpsilon with two layers, all Y+ wall treatment, multi-phase model (air/water), segregated flow with radiation model.
Fig. 20 - Simplified CAD model and Boundary condition
10 generations in a population of 8 configurations chosen from the best, previously tested in the DOE analysis. Results The results of the best iteration in minimum pressure drop (corresponding to the configuration process number 130) and in minimum sound level (corresponding to the configuration process number 82) are presented in Table 3.
The aim of the analysis has been the study of the A/C cabin, we have analyzed and verifyied the following parameters: • Velocity field (see Figure 21) • Relative humidity pattern (see Figure 22) • Temperature pattern in cabin zones (see Figure 23). • Cabin average temperature
The Parallel Coordinates in the diagram of Figure 18 illustrate the results for the r80 run configurations generated for the optimization. Figure 18 shows the acoustic FEA analysis, and Figure 19 shows the CFD pressure losses analysis. Evaluation of the A/C cabin thermal environment and the occupants’ thermal comfort Once the design of the air distribution system and of the air conditioning pack were completed, the final steps have been the evaluation of the cabin thermal environment and the passengers’ comfort assessment. This activity has been developed through the following steps: • Tri-dimensional cabin thermal model development. • Assemby of a complete mono-dimensional model. • Comparison between the two approaches. Tri-dimensional CFD cabin thermal model The tri-dimensional cabin thermal model has been developed in the StarCCM+ environment, through the following steps: • Domain definition: due to its symmetry, a 2 meter long section of the cabin has been analyzed. • Mesh construction: in order to study, in adequate detail, the distribution of velocity, temperature and humidity, a polyhedral mesh (with a prism layer for turbulence
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Fig. 21 - Velocity field
Fig. 22 - Relative humidity pattern
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temperature calculated with the CFD analysis is comparable with the average temperature calculated with the mono-dimensional model, assuming the same input conditions. The CFD model allowed to obtain a detailed evaluation of the cabin thermal environment, the temperature stratification, the stagnation zones, and the thermal environment near the passengers for evaluating the status of the passenger comfort. The mono-dimensional thermal model allowed, in a sufficiently accurate way, to obtain a fast evaluation of the cabin thermal environment in terms of average temperature and % of humidity. Fig. 23 - Temperature pattern
Passenger comfort requirements imposed by the aeronautical rules are: • Differential temperature between aft and forward side are not to exceed 2°C • Differential temperature between head and feet are not to exceed 3°C. • Differential temperature between left and right side are not to exceed 2°C. Considering as boundary conditions the data reported in Figure 20, our CFD model provides the following results: • Average relative humidity: 36.37% • Cabin average temperature: 23.8°C • As shown in Figure 23, the compliance with comfort requirements described above could be guaranteed. Complete ECS system mono-dimensional model. The complete mono-dimensional model has been obtained by linking the air conditioning pack model (see Figure 4) with the air distribution system model (see Figure 10), and with the A/C thermal model shown in Figure 6. The aim of the analysis was to study the A/C cabin thermal environment, analyzing and verifying the following parameters: • Average relative humidity • Cabin average temperature The analyses have been performed at different A/C and flight conditions. Considering as boundary conditions the data reported in Figure 20, our mono-dimensional model delivered the following results: • Average relative humidity: 40% • Cabin average temperature: 24.1°C. Results In order to evaluate the mono-dimensional model results (low fidelity model), its results have been compared with the CFD tri-dimensional model results (high fidelity model). The performed analysis has highlighted that the average
Conclusions Various new frontiers are currently emerging in the aerospace industry. They require new initiatives and approaches for the role of engineering design and analysis, mainly due to the profound knowledge of the importance of cross-firms and cross-disciplines collaboration in large scale engineering design processes, such as aircraft design. This kind of collaboration and interaction is now more possible than ever before due to the current state of digitization of engineering design data, an IT infrastructure that enables a universal communication of data, the current engineering platforms which support collaboration, and the increasing computational power, which allows us to integrate multidiscipline, multi-physics and engineering data in one shared environment. This state-of-art design environment is leading to a new opportunity, and to a challenge. As the present study shows, process integration between different design disciplines is an essential factor for automating design processes. The design process presented in this paper is actually used in the Environmental Control System department of Alenia Aermacchi, where fluid dynamic problems are approached with innovative tools and innovative methodologies that allow to define the architecture and to optimize the performance from the early stages of the system design. The described approach allowed to achieve the following reported goals: • Reduction/elimination of physical tests and related costs during the development phase. • Minimization of certification tests. • Minimization of risks and costs linked to the re-design of parts in the manufacturing phase. Alenia Aermacchi S.p.A. – G. Mirra, P. Borrelli, A. Romano Politecnico di Torino – M. Tosetti, L. Pace Università del Salento – B. Palamà, A. Camillò For more information: Francesco Franchini, EnginSoft [email protected]
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How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor return stable coupling of fixed parts, adequate freedom of moving parts and appropriate room to house electrical parts. For simplicity, we will call “functioning measurements” all those the contactor dimensions from which its reliable operation depends. In other words, if one or more functioning measurements is not comprised between assigned limits, the contactor assembly does not work properly and has to be rejected. Lovato Electric has been a prestigious Italian company operating Generally speaking, overall dimensions (including the in the electromechanical and electronic components market for functioning measurements) of a multi-part assembly depend on more than 90 years. Its wide catalog includes magneto-electric how both surfaces and edges of adjacent parts touch switches, contactors, sensors, digital multi-meters, soft-starters, themselves. From this point of view, the study of the assembly relays, automatic power factor correctors and other devices. Top geometrical properties becomes a tridimensional problem, whose quality, reliability and product variety make Lovato Electric a complexity grows with the number of contacts and shape of the star player in the world market. Company success is gained involved features. If parts had nominal shape, then the through constant valorization of internal competences and assembly would be univocally determined and solved by using parallel effective collaboration with customers and suppliers. any CAD tool. Real assembly conditions are far from the ideal In a past engineering service, EnginSoft was requested by ones, because real geometries exhibit a certain dispersion due Lovato Electric to investigate how the operation of an to the manufacturing processes. As a consequence, the assembly electromechanical contactor is influenced by dimensional and output is no longer univocally determinable and functioning geometrical tolerances of its components (GD&T analysis). measurements become dispersed as well. The contactor designer Electromechanical contactors constitute a relevant fraction of controls and limits the variability of the functional Lovato Electric production, so that the topic was perceived as of measurements (trying to keep them between the acceptance primary importance. limits) by assigning proper An electromechanical contactor is a dimensional and geometrical compact device including an tolerances to the components. The electromagnetic actuator investigation of how tolerances affect mechanically connected to a set of the dispersion of the functioning contacts. When the command signal measurements is carried out through a (a low power current) activates the statistical approach. internal inductor, a piston moves and change the connected contact status. The contactor that has been analyzed in the consulting service is composed Typically, this device is used to break a power circuit from changes by existing parts (i.e. taken from other production lines) and specifically location, without manually accessing designed new parts. EnginSoft the switch. The contactor is contribution has made possible to composed by both plastic and predict both mean values and metallic components held together by dispersions of the 5 functioning snapfeatures and screws. Plastic parts are manufactured by injection dimensions selected by the customer and shown in Figure 1. At the same molding process, while metallic parts time, an extensive sensitivity analysis are manufactured by cold forming of has made possible to identify the sheets. The contactor works reliably if factors influencing these dimensions, the assembly process creates both which are the key information to precise clearances and precise assess corrective strategies in case of interferences between parts, where unsatisfying distribution of the they are necessary. Fig. 1 - Contactor section highlighting the 5 outputs. Indeed, these geometrical conditions functioning measurements
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Newsletter EnginSoft Year 9 n°4 -
The service was completed through different tasks. First, the 3D CAD model was analyzed in detail to understand how the components interact and to select the surfaces involved in the contacts. Then, the dimensional chains were written accordingly. Each dimensional chain provides a vectorial representation of the geometrical relationships between component dimensions and functional measurements. For the analyzed device, it was found that 35 dimensions (among hundreds available) were affecting the functional measurements. As expected, the 5 dimensional chains resulted to be interdependent, since some dimensions were simultaneously included in more than one relationship. At the end of the problem definition, a virtual model of the contactor was developed, and the values of the 5 functioning measurements were calculated. A model used to investigate GD&T problems needs to faithfully reproduce geometrical interactions between parts. In order to meet such requirement, the virtual assembly is performed by putting into contact both surfaces and edges, instead of aligning planes and axes as we normally do in a CAD environment. The hardest phase of such work, which is also the deeper added value of this service, is really the mathematical description of the tridimensional interactions between component features. The model is finally parameterized, so that it includes the variability (in terms of position and size) of all geometrical details involved in the contact definition. Virtual measurements can be taken easily, in accordance to the model purposes. It is not difficult to see that a model with the mentioned characteristics, virtually reproduces any possible configuration of the multi-part assembly. From a different perspective, we could look at the model as to a numerical representation of the dimensional chains previously identified: it correlates the outputs (i.e. the functioning measurements), to the inputs (i.e. the component dimensions). The statistical investigation of the GD&T problem was carried out by assigning a normal distribution to each dimension of the components. This was an arbitrary choice, since we did not have information about. Obviously, we could have assigned any kind of distribution to each dimension. Mean values were picked in the middle of the corresponding tolerance ranges, while standard deviations were assumed as equal to 1/6 of the widths. These assumptions relate to the quality of the manufacturing processes we consider. By filling the tolerance range with 6 standard deviations, we implicitly assume that just 1 component out of every 370 has the considered dimension out of its tolerance. We investigated how tolerance effects propagate to the functioning dimensions, by generating a huge number of device configurations in a limited time. Distributions of the 5 outputs were then compared with the given acceptance limits, in order to identify the percentages of devices fulfilling the requirements. Main results are collected in Figure 2, the distributions of the 5 functioning measurements are compared to the corresponding requirements. All distributions are still of normal type, with symmetric shape. Plots highlight that significant fractions of the entire production are not meeting the operational requirements.
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Fig. 2 - Distributions of functioning measurements in the virtual production
The probability for a contactor to not be accepted after assembly is about 37%, mainly because the measurement n. 4 goes out of its acceptance limits. Plots of Figure 2 shows that non conformities can be caused by both an excessive width of the distribution (FUNC.MEAS.3) or a misalignement of the mean value with the acceptance range (FUNC.MEAS.2 and FUNC.MEAS.4). The statistical sensitivity analysis carried out on the population has made possible to select the dimensions (among the 35 involved) with the highest influence on the 5 outputs. Thus, appropriate adjustments were assessed to reduce the risk of non-conformity. In particular, the mean value of FUNC.MEAS.4 was moved to right (almost making null the area lying out of the acceptance bounds) by adjusting the nominal value of 2 component dimensions. This result really highlights the power of the GD&T analysis: an assembly issue is fixed with no need to narrow tolerance ranges. In other words, the reduction of rejected devices is obtained without increasing manufacturing costs. In this example, the collaboration between Lovato Electric and EnginSoft has returned valuable benefits. EnginSoft has simulated the assembly process through advanced numerical tools, providing crucial information about the relationships between component dimensions and final contactor performances. As issues were identified, proper corrections were planned and verified immediately. This has allowed Lovato Electric to shorten the physical prototyping phase, which turned into an effective reduction of overall production costs. For more information: Fabiano Maggio - EnginSoft [email protected]
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26 - Newsletter EnginSoft Year 9 n°4
Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot A novel slot-coupling feeding technique for wideband dualpolarized patch antennas is presented. A square patch is fed through a square ring slot excited by two non-overlapping feeding lines printed on the same side of a single-layer substrate. Reflection coefficient, port isolation and radiation patterns are evaluated by numerical simulations with ANSYS Designer and compared with measurements on an antenna prototype operating at the WiMAXTM 3.3-3.8 GHz frequency band (14% impedance bandwidth). Based on the slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly-polarized square patches, a single-feed circularly-polarized square patch, also in a stacked version, a 2x2 array of dual-polarized circular patches fed through a circular slot, a 2x1 array of stacked square patches fed through square slots. 1. INTRODUCTION The last years have seen a significant exploitation of printed antenna technology in mass production of planar arrays for base stations and subscriber units of cellular communication systems. Indeed, microstrip antennas are characterized by low profile, light weight, easy construction, and high flexibility in designing shaped-beam and multiband antennas. Although there are some considerable concerns regarding the microstrip antenna inherently resonant feature, a number of efficient techniques have been proposed to meet the large impedance bandwidth requirement of modern broadband communication systems. Furthermore, several dual-polarized patch
Fig. 1 - Some configurations of dual-polarized slot-coupled patch antennas, with different positions of the two coupling slots with respect to the patch center. Feeding lines with the same color are printed on the same side of the dielectric slab; in X1 an air bridge is needed to avoid line overlapping.
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configurations have been designed to be used as radiators in arrays for polarization-diversity based radio links. A common feeding technique for wideband antennas is based on slotcoupling, where a microstrip line is coupled to the radiating patch through a slot in a metallic ground plane, as first proposed by D.M. Pozar. Slot-coupled patches can exhibit a quite large impedance bandwidth at the cost of an affordable construction complexity, and allow for more space for the feed network with respect to microstrip fed arrays (the latter being an important need especially for dual-polarized dense phased arrays). Moreover, the metallic slot plane prevents the spurious radiation from the feed network and then reduces the amplitude of the cross-polar components. Finally, the two-layer structure allows for using a thick low-permittivity substrate for the patch (which guarantees a larger impedance bandwidth and a higher efficiency) and a thin high-permittivity substrate for the feed circuitry (as required to suppress radiation from the feed line and to save space for the feed circuitry). To extend the singlefeed, single-polarization design to the dual-polarization antenna design, a large number of aperture-coupled patch antennas have been presented in the open literature (most of them are shown in Figure 1). Dual-polarized microstrip antennas require the excitation of the two orthogonal fundamental modes of a microstrip patch. Dualmode excitation can be obtained by coupling the radiating patch to the feeding network through two orthogonal slots in a metallic ground plane: either a cross-shaped slot or separated orthogonal slots have been used. Besides gain and radiation pattern values, design concerns are also about the port isolation and the cross-polarization level, since they impact on the communication system performance. Both above properties are markedly related to the electrical and the geometrical symmetry properties of the antenna layout with respect to the principal radiation planes. Moreover, a symmetry property of the antenna with respect to the two input ports is also a valuable feature, as in this case the two polarization ports exhibit identical impedance and radiation characteristics. In this paper a novel dual-polarized slot-coupled feeding technique is presented. With respect to other slot-coupling feeding techniques for dual-polarized patch antennas, the proposed configuration exhibits a simple structure and a valuable
Newsletter EnginSoft Year 9 n°4 -
symmetry property with respect to the two feeding ports, while preserving a satisfying isolation between them (greater than 20 dB). A square patch is coupled to a pair of microstrip feeding lines by a square ring slot realized in a metallic ground plane, and both feeding lines are printed on the same side of a singlelayer substrate. Antenna layout performance is shown for a design relevant to a patch operating in the 3.3-3.8 GHz WiMAXTM frequency band. Simulation data agree with measurements on an antenna prototype. The proposed coupling technique is suitable for the design of large planar arrays with dual linear polarizations (vertical/horizontal polarizations or 45° slanted polarizations). Dual circular polarization can also be implemented by adding a 90° hybrid coupler. ANSYS Designer is the electromagnetic simulator code used for all patch antennas design. The physical quantities taken into account in all projects are the reflection coefficient, the isolation between the two channels in the dual polarization configurations, the axial ratio for circular polarized antennas, the gain and directivity, the 3D radiation patterns and the Eθ and Eφ components in the two principal antenna planes, the back radiation, the side lobes level. Each antenna element is parameterized in order to analyze each parameter effect on the antenna performance and in order to simplify the optimization process. For example, thanks to the parameterization, modifying the distance between two array elements elements is not necessary to re-design the feeding network. The simulated results are very close to the prototype measurements, also avoiding systematic errors that are committed in the measurement process, as implementation prototype errors, welds discontinuities, etc. The article is organized as follows. The novel slot-coupling feeding technique and its working principle are illustrated in Section 2 together with simulated results obtained with a fullwave commercial tool and with measurements on an antenna prototype. Section 3 describes the new feeding technique applications to some circular polarized arrays and stacked antenna. Finally, concluding remarks are drawn in Section 4. 2. A Square Ring Slot Feeding Technique The novel dual-polarized slot-coupled patch antenna fed through a square ring slot is shown in Figure 2. Both feeding lines are printed on the same side of a single layer substrate and a metallic reflector is added to limit the back radiation. It is apparent that the layout is symmetric with respect to the two input ports, which means that identical radiation and input impedance properties are expected. The latter represents a useful feature when designing a circular polarized patch (requiring an additional feeding circuit to generate two signals with the same amplitude and a 90° phase shift), or when designing the feeding network of a dual-polarized array. Moreover, since the slot and patch phase centers overlap, the radiation pattern main direction is not depointing at any frequency. The radiating elements are fed in ANSYS Designer through an edge port inserted between the microstrip line (printed on the dielectric substrate upper surface) and the antenna ground plane (on the other side of the same substrate). The proposed
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Fig. 2 - The square patch fed through a square ring slot: (a) stackup and (b) layout. Dimension of the geometrical parameters for a 3.5 GHz WiMAXTM antenna: P=22 mm, L=17 mm, K=0.5 mm, W1=2.5 mm, W2=3.7 mm, S1=2 mm, S2=6 mm, H1=22 mm, H2=11 mm.
feeding technique allows to simultaneously feed the patch by using two orthogonal microstrip lines, furthermore the above lines can be properly connected to get circular polarization. To evaluate the isolation between these two channels and to analyze separately the Eθ and Eφ components contribution generated by the two microstrip lines, it was necessary to insert two edge ports. To show the working principle and the radiation properties of the proposed slot-coupled patch, a sample antenna operating at the 3.3-3.8 GHz WiMAXTM frequency band has been designed, fabricated and characterized. It is worth noting that the proposed geometry can be used for any application requiring a planar dual-polarized antenna with a 10-15% fractional bandwidth (larger impedance bandwidth can be also obtained by adding a square stacked patch) and a 20 dB port isolation. In the sample antenna, both microstrip lines are printed on the same 90x90 mm2 Rogers RO4003 laminate (εr=3.55, tanδ=0.0027, thickness=1.524 mm), available in the ANSYS Designer material library. The low loss Roger RO4003 used for the antenna active part, although more expensive, allows to obtain higher antenna gain thanks to lower feeding line losses. Instead, the low cost FR4 was used to print the patches, electromagnetically coupled to the microstrip line. The stackup is shown in Figure 2a. The square ring slot has a perimeter of 68 mm (Figure 2b) and it is etched on the other side of the above substrate, namely on the metallic ground plane separating the feed lines from the square patch. As in other slot-coupled patch configurations, the ground plane prevents spurious radiation from the feed network and the length of the open-circuited stub behind the slot is optimized for input impedance tuning. A 160x160 mm2 square aluminum reflector is placed at a distance of 22 mm from the feed lines to reduce back radiation and increase the antenna gain. The 22x22 mm2 copper patch is printed on the bottom layer of a 90x90 mm2 FR4 laminate, which is 1.6 mm thick (it also acts as a cover for the antenna). The air gap between the patch and the slot plane is 11 mm thick. Figure 3 illustrates the electric field distribution inside the square ring slot when Port1 of the patch in Figure 2 is fed. It is apparent that the field distribution resembles that of the fundamental resonating mode of a ring slot. This is in agreement with the slot perimeter length that is close to the guided wavelength λg of a slotted line with the
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28 - Newsletter EnginSoft Year 9 n°4 same geometrical and electrical parameters as those of the slot: Oviedo. The frequency set for the mesh was thus chosen as 5 λg=66 mm at 3.5 GHz. The electric field distribution shown in GHz, which was a good compromise between mesh accuracy and Figure 3 reveals a number of interesting features. The side of simulation times (Figure 5). The sweep analysis was varied from the ring slot that is directly fed and that one parallel to it (i.e. 3000 to 4000 MHz. the vertical sides of the ring slot shown in Figure 2b) are both excited, and the electric field induced into the two slot sides Both measured and Designer simulated results for the reflection are in phase and with a similar amplitude; as a consequence, coefficient and port isolation are shown in Figure 6, and they due to above phase relationship and the symmetric position of exhibit a reasonable agreement. For both polarizations, the the vertical sides with respect to the reflection coefficient is less than -10 dB, patch center, the resonant mode of the from 3.3 GHz to 3.8 GHz (percentage patch (that one associated to Port1) is impedance bandwidth is 14%). The port properly excited and low crossisolation is greater than 20 dB in the whole polarization is expected. Moreover, the 3.5 GHz WiMAXTM frequency band. electric field distribution induced into the In Figure 7, the co-polar and cross-polar two sides of the slot orthogonal to the components of the radiation patterns, in the previous ones (i.e. the horizontal sides of θ=45° and θ=-45° radiation planes, are the ring slot shown in Figure 2b) are out shown, when Port2 is fed (indeed, dual-linear of phase and do not excite the orthogonal polarized antennas are usually used to resonant mode of the patch (that one Fig. 3 - Direction and amplitude of the electric implement base station antennas with ±45° associated to Port2). Finally, the induced field inside the square ring slot, when Port1 of slanted polarizations). Measured half power electric field does vanish close to the the antenna in Figure 2 is fed (ANSYS Designer beamwidth at 3.55 GHz is around 56° in both data). center of the horizontal sides of the slots; planes and cross-polar components are below
Fig. 4 - A square ring slot antenna prototype for 3.5 GHz WiMAXTM applications.
Fig. 5 - Antenna mesh at 5 GHz.
it means that a relatively high port isolation is expected when that point is used to couple the slot ring to the orthogonal feed line corresponding to Port2. It is worth noting that since the slot perimeter is less than the free-space wavelength (actually it is around a slot-line guided wavelength) and the patch perimeter is almost double the free-space wavelength, the whole square ring slot does always remain under the patch, for any design frequency. Finally, due to the perfect symmetry between the two ports, the same radiation patterns (in both E and H planes) and the same gain for the two ports are expected in the whole antenna frequency bandwidth. The presented novel layout can be seen as an advancement of “O” configuration in Figure 1. Indeed, it is apparent that the four-slot arrangement, symmetric with respect to the patch center, resembles the ring slot geometry. The significant difference is that in the novel configuration all four sides of the ring slot contribute effectively and correctly to the excitation of the two orthogonal fundamental patch resonant modes, while in the “O” configuration two of the four slots are parasitic elements. A 3.5 GHz WiMAXTM prototype (Figure 4) has been realized and measured in the anechoic chamber at the Department of Electrical Engineering of the University of
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Fig. 6 - Measured and simulated S-parameters of the square ring slot patch.
-18 dB in the broadside direction. Measured gain is between 8 dB and 8.7 dB in the band of interest (Figure 8). Similar results are obtained when Port1 is fed. 3. Square Ring Slot Technique Applications Basing on the ring-slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly polarized square patches (Figure 9), a single-feed circularly polarized square patch, also in a stacked
Fig. 7 - Measured and simulated co-polar and cross-polar components for the square slot patch in Figure 2, at f=3.55 GHz when Port2 is fed: (a) θ=45° plane and (b)θ=-45° plane.
Newsletter EnginSoft Year 9 n°4 -
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version (Figure 10), a 2x2 array of dualdesigned to increase the percentage polarized circular patches fed through a bandwidth up to 44.5% in order to be circular slot (Figure 11), a 2x1 array of used at base stations where wideband stacked square patches fed through square antennas are needed (e.g. base stations slots (Figure 12). In Figure 9, the sequentially for GSM, PCS, UMTS, WLAN applications). rotated 2x2 array prototype with a complete The simulation times, for all the microstrip feeding network is shown. Each antennas designed and presented in this dual-linear polarized patch has been fed paper, vary between 15 and 60 minutes, through a reactive 3 dB power divider in order depending on the antenna operating to have a single feeding line. The feeding band and the radiating elements number network consists of microstrip lines whose Fig. 8 - Measured and simulated gain of the in the configuration. The ANSYS Designer square ring slot patch in Figure 2, when Port2 lengths have been adjusted to achieve the is fed. simulation process has saved a lot of required 90° current phase difference time: the prototype procedure (up to between adjacent elements. To get a wide impedance and wide connectorization process) and measured process is very axial ratio bandwidth, a sequential rotation feeding technique onerous: the prototype process was about 60 minutes, the has been adopted. A single feed slot-coupling solution has radiation patterns measurements component for a single plane been applied to gain circular polarization. A meandered slot is at a single frequency was about 2 minutes). Then this procedure designed to excite two orthogonal modes and the same kind of was repeated for each plane, both the components and the perturbation is applied to the patch. To preserve the antenna entire band of interest. Moreover, it is necessary to take symmetry, two identical meanders have been added on two account of the entire prototyping and measurement cost (the opposite sides of the square ring. Both width and length of the materials cost, the instrumentation, the available facilities). It above slots have been optimized. To improve axial ratio was therefore fundamental to get to the measurement stage performance, a stacked solution has been proposed (Figure 10) with reliable projects, obtained with ANSYS Designer. to get a 12% 3 dB axial ratio bandwidth. Basing on Figure 9, the configuration shown in Figure 11 is 4. CONCLUSIONS designed with both circular slot and patch. The performances of A novel wideband slot-coupled patch fed through a square ring the two configurations are shown and compared for two slot has been presented and design criteria have been fabricated prototypes. Antennas shown in Figure 9 and Figure discussed. Owing to its simple structure, the patch described 11 have been designed to operate in the WiMAXTM frequency here can be used as the radiating element of medium and large band around 3.5 GHz. The configuration shown in Figure 12 is planar arrays with dual linear polarizations (vertical/horizontal a 2x1 array of square stacked patches. This antenna has been polarizations or ±45° slanted polarizations). Antenna performance in terms of port isolation and cross-polar component level has been shown through the design, fabrication and characterization of a patch operating at the 3.3-3.8 GHz WiMAXTM frequency band. A 20 dB port isolation has been obtained, in a 500 MHz frequency band (14% fractional bandwidth), with cross-polar level less than -18 dB at the broadside direction. We have also experienced that the final design of the proposed solution is a result of a trade-off between frequency bandwidth enlargement and isolation improvement. Impedance bandwidth enlargement can be Fig. 10 - Single-feed circularly polarized achieved by adding either stacked patches or other parasitic Fig. 9 - 2x2 array of dual-feed stacked square patch for 3.5 GHz circularly polarized square patches elements close to the main radiating patch, while preserving WiMAXTM applications. for 3.5 GHz WiMAXTM applications. the original symmetry properties. Finally, due to the symmetry of the antenna layout with respect to the two feed ports, good axial ratio performance can be obtained when it is used to radiate a circularly polarized field.
R. Caso, A. Buffi, P. Nepa - Department of Information Engineering, University of Pisa A. Serra - EnginSoft Fig. 11 - 2x2 array of dual-polarized circular patches fed through a circular slot for 3.5 GHz WiMAXTM applications.
Fig. 12 - 2x1 array of stacked square patches fed through square slots for GSM, PCS, UMTS, WLAN applications.
For more information: Andrea Serra, EnginSoft [email protected]
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30 - Newsletter EnginSoft Year 9 n°4
Grapheur for Material Selection In this article the criteria of mechanical behavior of the MCDM for Material selection woven textile composites during the draping and the further When multiple criteria from different disciplines are to be involved simulations and analysis are included in the process satisfied in a material selection problem, often complexities of the optimal design and decision making. For this purpose, the advanced software architecture of Grapheur for interactive optimization and MCDM is utilized. In this software the identified challenges of utilizing MCDM are improved via connecting the data mining/visualization and optimization through the user interaction. For the optimal Fig. 1 - Simulation of the draping process design of composites, with the aid of advancement of interdisciplinary and data analysis tools, a series of criteria including mechanical, electrical, chemical, cost, life cycle assessment and environmental aspects aspects can now be simultaneously considered. As one of the most efficient approaches, the MCDM applications can provide the ability to formulate and systematically Fig. 2 - A combination of four different simulation criteria including the compression, bend, compare different alternatives against the large stretch, and shear form the draping a) Mechanical modeling of the bending; the behavior of sets of design criteria. However, the mechanical textile under its weight is simulated by manipulating the related geometrical model within behavior of woven textiles during the draping the CAGD package. b) Geometrical model increase due to criteria conflicts. Many applications and process has not yet been fully integrated into the optimal algorithms of MCDM have been previously presented to deal design approaches of the MCDM algorithms. with decision conflicts often seen among design criteria in material selection. However, many of the identified Introduction In the integrated engineering design process and optimal drawbacks and challenges are associated with the applicability. design, the material selection for the composite can determine the durability, cost, and manufacturability of final products. The process of material selection begins with Draping indentifying multiple criteria properties of mechanical, The manufacturing of woven reinforced composites requires a electrical, chemical, thermal, environmental and life cycle forming stage so-called draping, in which the preforms take costs of candidate materials. However, the mechanical the required shapes. The main deformation mechanisms behavior of woven textiles during the draping process has during forming of woven reinforced composites are not yet been fully integrated into the optimal design compression, bend, stretch, and shear which cause changes approaches of the MCDM algorithms. in orientation of the fibers. Since fiber reorientation
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Newsletter EnginSoft Year 9 n°4 -
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Fig. 3 - Geometrical modeling of double dome utilizing the Khabazi [11] algorithm.
influences the overall performance, it would be an important factor that should be taken into account along with the other criteria. Mechanical modeling and simulation of the draping The mechanical models of drape involve much higher computational cost when compared to the kinematic models; yet, they offer the benefit of representing the non-linear material behavior. Moreover the mechanical simulation, as the most promising technique, gives a real-life prediction of the fiber reorientation. Geometrical modeling and simulation of the woven textiles Moreover, of all the approaches for the geometrical modeling of woven textiles presented so far, the Spline-based methods are the most effective technique. In fact, the Spline-based geometrical representation of a real-life model of any type of flat-shaped woven textile, is realized by implementing the related computer-aided geometrical design (CAGD) code. However, the mathematical representation of a woven multiple-dome shape, in the practical scale, may not be computationally valid. In order to handle the computational complexity of geometrical modeling the multiple-dome woven shapes, utilizing the NURBS-based CAGD packages are essential. Khabazi introduced a generative algorithm for creating these complex geometries. His improved algorithm is capable of producing the whole mechanism of deformation with combining all details of compressed, bended stretched and sheared properties. It is assumed that if the mechanical behavior of a particular woven fabric of a particular type and material is identified then the final geometrical model of the draping could be very accurately approximated. In this
technique the defined mechanical mechanisms of a particular material, in this case glass fiber, is translated into a geometrical logic form integrated with the NURBS-based CAGD package through a process called scripting. Integration the MCDM-assisted material selection with draping simulation In order to select the best material of a woven textile, the draping simulation needs to be carried out for a number of draping degrees. The results of all the draping simulations of different drape angles are gathered as a challenge and opportunity Nowadays, more and more enterprises can afford to enlarge their data storage means at will. Information that a few years ago would have been thrown away is now kept in the main storage area, ready to be retrieved and analyzed. Enterprises are now discovering that they lack the means to draw insights from this large amount of data: while storage room builds up nicely, communications and processing power needed to extract useful information from data is beyond their reach. Such power is now made available thanks to parallel processing platforms such as Apache Foundation’s Hadoop, however their use remains a big challenge for most organizations. The LION difference: machine learning and optimization Consider a web server farm as used by many enterprises. Every webpage accessed by a visitor results in the addition of a line of text to a log file recording the instant of of the request, its source, and many other pieces of information (similar logs are produced by activity in social networks like Twitter, Facebook, etc). Server logs keep growing and, to avoid unusably large files, they are broken into smaller files and eventually moved to different disks. When the LIONsolver machine learning and optimization platform is combined with a Hadoop implementation for web log analysis, previously unknown patterns emerge that show the behavior of customers in a website. For example, event data,
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such as video views, email registrations, or literature downloads can be correlated to engagement (time on site), pages visited and interacted with (suggesting the efficacy of web design) and ultimately with purchase follow through. As shown below, LIONsolver drives the flow of data and computation in the Hadoop system, visualizes the results once they are made
available by the framework, develops models by 'learning from data' and suggests improving strategies. LIONsolver goes beyond simple visualizations to show correlations that impact business decisions to inform customer and content targeting, web design, business rules, and so on. For more information, visit http://lionsolver.com/ or contact us at [email protected]
Newsletter EnginSoft Year 9 n°4 -
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Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura Nello studio di processo di produzione per deformazione a caldo di una forcella in acciaio C25 è stato affrontato anche il problema della resistenza a frattura duttile degli stampi. Eseguendo una preventiva analisi del processo di produzione di una Forcella, è stato possibile valutare l’influenza dei diversi parametri dell’intero processo produttivo, successivamente sono state condotte analisi FEM delle diverse fasi di progetto per poter definire gli stati tensionali e deformativi del materiale in deformazione e degli stampi, mediante codice numerico. Si sono potute così valutare le diverse cause del fenomeno di bassa durata produttiva degli stampi, calcolando i valori di intensificazione delle tensioni nei punti in cui nella realtà si verifica l’innesco della cricca. E’ stata inoltre studiata l’ottimizzazione dell’intero processo, per ottenere un prodotto integro da difetti, un miglioramento del comportamento a fatica degli stampi ottenendo benefici produttivi sia economici che energetici. Introduzione I processi di lavorazione per deformazione plastica sono un campo di estremo interesse per le moderne tecniche CAE vista la complessità teorica dei singoli processi e l’influenza dei vari parametri. In particolare il processo di deformazione a caldo di acciaio in stampi chiusi è stato storicamente uno dei primi processi investigati attraverso le tecniche di simulazione numerica. Ciò soprattutto per l’elevato grado di ripetibilità della “massiva” produzione di dato processo e dei numerosi parametri in gioco. Un approccio di tipo FEM (Finite Element Method) è il più adatto allo studio del processo nel suo dettaglio, con la possibilità di previsione delle tensioni e delle deformazioni indotte dalla lavorazione per deformazione plastica a caldo. L’applicazione di tale metodologia è assai complessa, vista la non linearità di comportamento del materiale che viene schematizzato con un modello elasto-visco-plastico. Il problema che il tecnologo di produzione si trova ad affrontare è quello di definire le diverse fasi di stampaggio per trasformare il disegno del pezzo finito nel disegno del grezzo e della
cavità degli stampi, con un procedimento che segue diverse fasi di progetto. Lo stampaggio prevede un ciclo di lavoro molto complesso, con aspetti che richiedono competenza scientifica ed esperienza per la definizione delle diverse fasi in maniera corretta sia per l’ottenimento di un corretto manufatto esente da difetti, sia nella scelta della soluzione più economica. Lo studio condotto si prefigge l’obiettivo di dare un contributo significativo allo sviluppo di tecniche per la progettazione e l’ottimizzazione dei processi di lavorazione per deformazione di acciai. L’intero progetto ha lo scopo di poter migliorare il controllo del processo di deformazione, l’analisi delle difettosità, delle forze e delle sollecitazioni a fatica degli stampi su base ripetibile in ambiente produttivo della moderna realtà industriale. Il componente forgiato preso in esame è una forcella, organo meccanico di collegamento atto alla trasmissione di forze statiche e dinamiche, prodotto in tre passaggi: Preformatura, Abbozzatura e Finitura. Nella prima parte dell’attività si è esaminato lo stato dell’arte del processo di produzione del particolare preso in considerazione, conducendo studio FEM del processo reale: studio della parte “teorica” di processo, introduzione ed approfondimento delle basi della fisica, meccanica e strutturale per comprendere le dinamiche della deformazione plastica a caldo di un materiale metallico, le metodologie e le operazioni che li caratterizzano. Nell’ultima fase di stampaggio, Finitura, dopo un numero esiguo di prodotti, si riscontra nella realtà produttiva il fenomeno di rottura dello stampo superiore in una regione ben localizzata di concentrazione degli sforzi. Lo studio si è focalizzato sull’analisi di tale fenomeno, il quale inficiava la produttività reale del processo, ponendosi l’obiettivo di minimizzare il carico pressa necessario alla deformazione, e ottimizzare il binomio processo/prodotto variando le condizioni a contorno, nel pieno rispetto dei vincoli di completo riempimento e nulla difettologia sul forgiato finale.
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34 - Newsletter EnginSoft Year 9 n°4 L’ottimizzazione è stata condotta sull’intero processo, concatenando le diverse operazioni di forgiatura intimamente accoppiate con l’evoluzione termica del componente in deformazione e nelle fasi intermedie di passaggio da una all’altra operazione. I risultati hanno permesso di correlare la variazione dei principali parametri di processo ai benefici ottenuti: risparmio di materiale (benefit economico) e diminuzione di onerosità di processo (benefit energetico-economico-ecologico). Nella parte finale dello studio, ci si è concentrati nell’analisi di sollecitazione degli stampi con approccio disaccoppiato. Si è testato attraverso analisi FEM, dapprima la riproduzione di sollecitazione e plasticizzazione dello stampo nelle aree di innesco rottura, con verifica del numero di cicli e previsione di vita utile prima di arrivare a rottura duttile; in un secondo momento si è testato come le condizioni di ottimo apportassero significative migliorie anche al fenomeno di “rottura a fatica”. Processo di deformazione plastica a caldo Le lavorazioni per deformazioni plastica di materiali metallici hanno origini lontanissime nella storia della tecnica. Sottoposto all’azione di forze esterne tramite presse o magli, il materiale varia permanentemente la sua forma originale; tale trasformazione avviene allo stato solido-viscoso. I processi di lavorazione per deformazione possono essere suddivisi in: • primari, utilizzando materiale da fusione e ottenendo semilavorati commerciali destinati ad uso diretto o ad ulteriori deformazioni; • secondari, da prodotti di deformazione primaria si ottengono manufatti di forma e dimensioni finite.
stampaggio a caldo è una tipica lavorazione per produzione di grande serie. Di contro lo svantaggio è quello di necessitare di energia per il riscaldo, favorire l’ossidazione del metallo ed inoltre risulta difficile prevedere la precisione dimensionale ottenibile. La billetta iniziale è uno spezzone quadro (sezione 120x120 mm, raccordo R20, lunghezza 327 mm, peso 36 kg) proveniente da deformazione primaria, in C25/1.0406, il volume della billetta
Fig. 2 - Bielletta iniziale in C25. Forcella Forgiata - Prodotto Finito
tiene conto anche della maggiorazione della percentuale di perdita di materiale per ossidazione (calo termico); mentre il prodotto finale di forgiatura è una forcella di trasmissione meccanica (Fig.2). Lo spezzone di acciaio viene riscaldato in forno con lo scopo di arrivare alla temperatura idonea di stampaggio, che deve essere la più alta possibile, rimanendo tuttavia distante dal punto di La corretta progettazione dello stampaggio deve assicurare un fusione per evitare liquefazioni e bruciature di materiale: circa corretto e completo riempimento degli stampi, studiandone i parametri ed i fattori che lo influenzano: 1250°C. Tale temperatura deve essere maggiore di quella critica di transizione vetrosa per poter sfruttare la migliore deformabi• deformabilità e resistenza allo scorrimento; lità, il materiale a tale temperatura ha una caratteristica elasto• uso di lubrificanti; • temperatura della parte deformabile e degli stampi; visco-plastica. Il tempo che intercorre dall’uscita forno al primo step di deformazione provoca una caduta termica della superfi• forma del pezzo finale; • calcolo della forza necessaria. cie della billetta che scambia calore con l’aria circostante (minimizzazione del tempo di fuori forno). Nella maggior parte dei casi di processo di stampaggio è necesI processi di deformazione a caldo avvengono ad una temperasario deformare progressivamente il materiale di partenza, per tura maggiore della temperatura critica di ricristallizzazione, i garantire un riempimento accurato degli stampi e per ottenere vantaggi di tale metodo sono sia le minori forze e potenze riuna valida distribuzione delle fibre all’interno del prodotto finachieste, sia la possibilità di indurre grandi deformazioni e l’ottele. La non uniformità di deformazione influenza negativamente nimento di forme anche complesse, grazie alla maggior duttilità le caratteristiche meccaniche finali dello stampato, per cui eledei metalli alle alte temperature (Fig1). Limitando le forze nevata cura va profusa nello studio dell’intero processo. Spesso si cessarie e sfruttando la migliore deformabilità del materiale, lo necessita quindi di sbozzati intermedi la cui forma e dimensione è mediata tra lo spezzone iniziale e lo stampato finale, attraverso stampi sbozzatori, con caratteristiche simili a quelli finitori, possono essere ottenuti tali sbozzati. Il processo industriale reale è uno stampaggio in tre fasi deformative: Preforma, Abbozzatura e Finitura. Tutte e tre le fasi di Fig. 1 - Deformazione Plastica di un Materiale metallico e proprietà. Effetti dell’incrudimento sulle stampaggio sono ottenute dall’azione della caratteristiche meccaniche. Effetti della temperatura sulle caratteristiche meccaniche di un materiale Pressa Meccanica (Fig.3) che impartisce il metallico.
Case Histories
Newsletter EnginSoft Year 9 n°4 -
Fig. 3 - Pressa Meccanica. Sx Schema di una pressa meccanica ad eccentrico. Dx Cinematismo Biella-Manovella
cinematismo. La pressa meccanica utilizzata nel processo industriale analizzato ha le seguenti caratteristiche cinematiche: Raggio di manovella = 100 mm, Velocità di rotazione = 55 rpm, Rapporto (raggio di manovella)/(Lunghezza di biella) = 0.14285. L’organo mobile con un moto alternativo esercita una forza sul materiale da deformare, durante la sua corsa attiva fino al Punto Morto Inferiore. In tale punto di lavoro la forza disponibile tende all’infinito, ma i costruttori limitano con dispositivi di protezione, la forza massima esprimibile in deformazione ad un valore detto nominale. La forza richiesta dal processo di deformazione deve essere sempre inferiore a quella disponibile. La prima deformazione è in gergo una tipica ricalcatura dello spezzone per discagliatura successiva al riscaldamento in forno ed un miglior posizionamento all’interno della sagoma della stazione di deformazione successiva. La billetta deformata viene collocata sullo stampo inferiore di Abbozzatura, in modo da poter coprire il più possibile il vuoto ricavato nello stampo, e quindi la figura da dover ottenere. In questa seconda fase, al contrario di quella di Ricalcatura in cui gli stampi sono piani, il materiale deve riempire il vuoto fra gli stampi, e quindi deve scorrere sulla loro superficie sotto l’azione della Pressa Meccanica che impartisce il cinematismo. La fase di Abbozzatura presenta un posizionamento della billetta ricalcata che non è univoco, infatti non sono state predisposte sullo Stampo Inferiore delle staffe di appoggio e trattenimento della billetta deformata proveniente dalla fase di Ricalcatura. E’ stata fatta la scelta di posizionare la billetta in modo che la superficie superiore coincidesse con la fine della superficie cava dello stampo inferiore, il robot antropomorfo ha un errore trascurabile nella determinazione di tale posizione. A fine deformazione l’abbozzato ha una forma moto simile a quella del prodotto finito, ma, in questa fase di deformazione, naturalmente, non viene richiesto né un riempimento ottimale né l’assenza di difetti, quali ripieghe. L’abbozzato viene tolto dalla cavità degli stampi tramite l’ausilio di un apposito estrattore, il manipolatore lo posiziona nella cavità dello stampo finitore; avendo una forma molto simile la figura riesce ad auto centrarsi per gravità nella posizione corretta desiderata. Sotto l’azione della stessa Pressa Meccanica, il manufatto viene portato a dimensioni nominali di progetto, il fi-
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nito rispetta la condizione di completo riempimento degli stampi, non presenta difetti nelle parti in cui non possono essere tollerati nella qualità di produzione ed ha un’altezza di bava pari a 5 mm. Il finito di stampaggio verrà successivamente sottoposto al processo di eliminazione della bava, sempre in linea quindi a caldo, trattamento termico, pulitura superficiale, coniatura e controllo prima di essere inviato alle macchine utensili per le lavorazioni per asportazione di truciolo. Sebbene il processo non presenta difetti di stampaggio, si nota prima di tutto che il materiale iniziale utilizzato per lo spezzone di billetta potrebbe essere minimizzato, visto il peso rilevante occupato dalla bava; secondariamente, in ordine di tempo ma non di importanza, si evidenzia come dopo un numero di cicli esiguo per una larga produzione di serie si arrivi alla rottura degli stampi. Studio di Processo attraverso Analisi FEM Lo studio del processo reale è stato condotto attraverso codice numerico che permettesse dapprima di poter definire tutti i parametri di processo e poi poterne studiare, secondo la loro variazione, le influenze nel processo stesso. E’ stato implementato l’intero ciclo di stampaggio partendo dalla billetta fredda dimensionata secondo progetto reale ed il suo inserimento in forno, fino alla completa deformazione in fase di Finitura; nel Codice Numerico è stato implemento un chaining delle varie fasi di stampaggio, in modo da poter automaticamente far calcolare l’intera sequenza e seguire in essa l’evoluzione del comportamento del materiale in deformazione, con particolare attenzione alla termica del processo, alle tensioni ed alle sollecitazioni. La modellazione del processo nelle sue diverse fasi prevede non solo quella geometrica, di facile implementazione con i moderni CAD, ma anche quella fisica, in cui il materiale, la termica ed i contatti rivestono ruoli primari. Il materiale della parte deformabile è descritto tramite il modello di Hansel Spittel (Fig.4), mentre gli stampi in ogni fase di stampaggio sono considerati come elementi indeformabili, infinitamente rigidi ed a temperatura costante (temperatura a regime). Lo scambio termico è definito in modo da descrivere il fenomeno sia quando la billetta è a contatto con gli stampi (αT = 2.0e+04 W/m²°K; effus = 1.176362e+04), sia quando non lo è e quindi scambia calore con l’ambiente circostante (αText = 10.0e+00 mW/mm/°C); per la velocità di esecuzione di proces-
Fig. 4 - Coefficienti del modello di Hansel Spittel del C25/ 1.0406
Case Histories
36 - Newsletter EnginSoft Year 9 n°4 so di deformazione alla pressa meccanica, ci si aspetta che l’influenza dello scambio termico sia di bassa rilevanza tra i diversi parametri in gioco. Attraverso la Legge di Coulomb-Tresca, l’attrito è stato definito in maniera conforme alla realtà dei diversi setup delle fasi di processo reale; in fase di abbozzatura non viene interposto alcun lubrificante, mentre le fasi successive di abbozzatura e finitura hanno una lubrifica spinta per poter far scorrere il materia- Fig. 6 - Lo stampo superiore, nella fase di finitura, presenta rottura dopo un numero esiguo di le in deformazione nelle parti vuote dello stampate, rispetto alla totale produzione, concentrata in una determinata zona ben visibile. Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC. stampo. E’ stato quindi implementato un coefficiente alto di attrito in fase di abbozzatura (m = 0.6; µ = 0.3) stampo in fase di finitura (quello che nella realtà subiva la rote più basso in fase di abbozzatura e finitura (m = 0.1; µ= 0.05) tura dopo un esiguo numero di cicli di stampaggio). A tale scorispettando l’omogeneità di distribuzione dei lubrificanti che po si è adottato un modello dello Stampo di Finitura deformabinella realtà è ottenuta in maniera automatizzata. le, sia elasticamente che elasto-plasticamente, ed è stato calcoTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la lato il grado di sollecitazione e deformazione elasto-plastica traperfetta implementazione cinematica del manovellismo della mite la proiezione su di esso delle forze ricavate dal modello a pressa meccanica precedentemente descritto. Tra una fase di stampi rigidi. Dall’analisi delle sollecitazioni dello stampo dustampaggio e quella successiva è stato implementato il calcorante la fase di finitura si evidenzia, nella parte finale di deforlo della caduta termica in aria per un tempo necessario alla mazione, la concentrazione di elevati valori della tensione prinmovimentazione reale della billetta, ottenendo quindi una cipale (1srPrincipalStressTensor) in quella che nella realtà appamappa della temperatura più adiacente alle condizioni reali di re come la linea di innesco della frattura (Fig.6); se positivo, il stampaggio. 1srPrincipalStressTensor rappresenta il massimo sforzo di trazione, ed il superamento di valori critici è il primo fattore di rottuTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la ra fragile. I valori pur non superando quelli critici hanno caratperfetta implementazione cinematica del manovellismo della tere ciclico, per cui la fenomenologia da indagare è quella di rotpressa meccanica precedentemente descritto. Tra una fase di tura per fatica oligociclica. stampaggio e quella successiva è stato implementato il calcoLo stampo superiore, nella fase di finitura, presenta rottura dolo della caduta termica in aria per un tempo necessario alla po un numero esiguo di stampate, rispetto alla totale produziomovimentazione reale della billetta, ottenendo quindi una ne, concentrata in una determinata zona ben visibile. Il materiamappa della temperatura più adiacente alle condizioni reali di le stampo è X37CrMoV5 H11 bonificato 42 HRC. stampaggio. I risultati ottenuti dal calcolo FEM, sono stati confrontati con quelli reali di stampaggio validando la scelta dei nuFenomeno di Rottura per Fatica Oligociclica merosi parametri di processo assunti nelle varie fasi. La forma fiLo studio condotto ha permesso di legare la fatica ai fenomeni nale dello stampato, la sua mappa termica e le forze di stampagdi micro-deformazioni plastiche cicliche locali indotte dal ciclo gio calcolate sono identiche a quelle ottenute nella realtà, così di sollecitazioni, il cui valore di sforzo localmente può superare come i difetti di ripieghe sono collocati negli stessi punti, cioè il carico di snervamento anche se il carico macroscopico esterno in bava e nelle zone di lavorazione meccanica successiva. rimane sempre al di sotto di esso. Il danneggiamento per fatica Tale studio preliminare condotto ha avuto l’obiettivo di modelprocede attraverso un primo assestamento microstrutturale, che lare le condizioni reali di processo, fino a poter valutare il grastabilizza il ciclo di isteresi plastica dello stampo metallico e, di do di sollecitazione degli stampi durante il processo deformaticonseguenza, stabilizza alcune caratteristiche meccaniche e fisivo. Gli stampi, come precedentemente affermato, sono stati asche dello stesso. Si generano microintagli dovuti a slittamenti sunti come infinitamente rigidi ed indeformabili, per cui la se'disordinati' dei piani cristallini del metallo che nella successiconda fase di studio, partendo dai risultati validati, ha valutato, va fase di nucleazione andranno a costituire l'innesco del dancon approccio disaccoppiato, lo stato di sollecitazione dello neggiamento per fatica. Gli sforzi risultano amplificati per effetto d'intaglio cosicché facilmente il materiale in quel punto cede e si formano delle microcricche. Queste tendono a riunirsi andando a formare la cricca vera e propria, che si considera ormai nucleata quando raggiunge la profondità di circa 0,1 mm. Dopo la nucleazione della cricca, la sua propagazione avviene in maniera fragile e in senso perpendicolare a quello del massimo sforzo. L'avanzare della cricca porta ad una progressiva diminuzione di sezione resistente: quando questa diventa inferiore alla Fig. 5 - Risultati delle simulazioni di stampaggio
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Newsletter EnginSoft Year 9 n°4 -
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sezione critica, si ha la frattura finale di schianto per sovraccarico (statico). La resistenza a fatica degli stampi è frutto della combinazione di stress meccanici e termici, in Fig.7 è rappresentata qualitativamente la metodologia di Valutazione composita delle componenti meccaniche e termiche della deformazione, ciò ha permesso di stimare la vita utile dello stampo studiandone la sollecitazione ed i suoi effetti di fatica (Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC). Al fine di valutare eventuali variazioni termiche sullo stampo, sono state analizzate le temperature della billetta in corrispondenza della zona maggiormente sollecitata ed i fattori metallur- Fig. 7 - Valutazione composita delle componenti meccaniche e termiche della deformazione gici di influenza Il limite di fatica si lega inevitabilmente: Con algoritmi di tipo MAES (Meta-model Assisted Evolution • alla tensione di rottura Rm ed ai fattori che la modificano; Strategies MAES) si utilizza una valutazione delle minimizzazio• fattori meccanici legati all'esercizio e al dimensionamento ni e dei vincoli per selezionare gli individui che si vogliono efdel prodotto metallico; fettivamente calcolare. Ci sono differenti tecniche per costruir• la finitura superficiale e la corrosione. lo e il tempo di valutazione usando il Meta Model varia in funzione della tecnica scelta ma in tutti i casi esso è molto più breAnche la forma del pezzo ha importanza sulla vita a fatica, ogni ve della semplice analisi FEM ed è quindi possibile incrementalieve variazione di sezione, determinando delle concentrazioni di re la dimensione della popolazione mantenendo il tempo per tensioni e localizzando le deformazioni, agisce sempre nel senl’ottimizzazione pressoché costante. so di una netta diminuzione del limite di fatica, per questo hanno un'azione dannosa fori, intagli e spigoli vivi. Ottimizzazione di Processo Lo studio di lavorazione per deformazione fin qui descritto è stato propedeutico alla ricerca del miglior setup per l’individuazione dell’ottimo binomio prodotto/processo ed all’analisi avanzata dell’influenza dei vari parametri. Si è proposto quindi l’impiego di un approccio statistico da correlare alla fase di raccolta dati che permettesse alla progettazione di raggiungere i seguenti risultati: • riduzione dei tempi di sviluppo dei processi; • uso più efficiente delle risorse; • maggiore affidabilità dei processi. Nell'ambiente industriale la complessità dei fenomeni impedisce il pieno controllo dei fattori sotto indagine e una conoscenza teorica completa: ciò significa che non sempre è nota a priori la relazione di causa-effetto tra i fattori che influiscono sul processo in esame e le variabili da ottimizzare, una delle tecniche di progettazione per massimizzare le informazioni derivanti da dati sperimentali è il Design of Experiments (DOE), metodo che consta di due fasi principali: • fase di screening: identificazione dei fattori significativi e loro correlazione; • fase di ottimizzazione: identificazione della risposta. La scelta dell’algoritmo nel codice numerico utilizzato è di tipo generico: • iniziare da una popolazione: un numero predefinito di individui che può essere definito prima generazione; • valutarli (calcolarli e valutare minimizzazioni e vincoli); • selezionare i migliori, riprodurli e creare una nuova generazione.
Fig. 8 - Scelta casuale della popolazione iniziale rispetto al numero dei parametri
Tali algoritmi presentano la limitazione di richiedere diverse centinaia di valutazioni e di simulazioni complete; la Strategia di Evoluzione Assistita da Meta-Model (MAES) rende possibile ridurre considerevolmente il numero dei calcoli effettivi. Si possono ottenere buoni risultati all’interno di poche decine di calcoli e grazie al calcolo parallelo, le analisi/simulazioni possono essere condotte allo stesso tempo riducendo il tempo di ottimizzazione. Gli algoritmi evolutivi (ES) consistono tipicamente di tre operazioni: selezione, ricombinazione e mutazione, per ridurre il numero di valutazione di funzioni. Lo studio di ottimizzazione condotto sul processo deformativo preso in considerazione può essere riassunto nella scelta dei target della funzione Obiettivo da minimizzare, parametri di variazione e vincoli da rispettare: Target Obiettivo di ottimizzazione • Minimizzazione volume iniziale billetta. • Minimizzazione carico pressa durante la fase di abbozzatura. • Minimizzazione carico pressa durante la fase di finitura. Vincoli di ottimizzazione • Completo riempimento stampi in fase di finitura. • Assenza di difetti di stampaggio in fase di finitura.
Case Histories
38 - Newsletter EnginSoft Year 9 n°4 Analizzando non solo i setup efficaci, ma l’intera popolazione di parametri scelti nei ranges di interesse, si sono valutate le influenze che la variazione di parametri scelti hanno sul carico degli stampi in fase di abbozzatura e soprattutto di finitura, visto che questa è la fase in cui la rottura degli stampi avviene dopo un numero esiguo di cicli di stampaggio. Fig. 9 - Intera popolazione di individui di ottimizzazione. La variazione di massa della billetta iniziale riflette una variabilità estremamente accentuata della forza di stampaggio nella fase di abbozzatura, mentre nella fase di finitura, così come ci si aspetta dalla configurazione della fase di stampaggio, presenta una più modesta minimizzazione. Il grafico di Fig.9 riporta la totalità dei casi analizzati. Nel grafico di Fig.10 si riporta l’andamento Fig. 10 - Individui che soddisfano i vincoli della forza di stampaggio in funzione della massa iniziale di billetta, solo per i 21 casi (su 40) soddisfacenti il vincolo di completo riempimento e nessuna ripiega in finitura, si evidenzia come la ricerca dell’ottimo, pur spaziando su tutto il range, si concentra nella zona di minimo carico e minimo volume. Nel grafico di Fig.11 si riporta l’andamento della forza di stampaggio in funzione del posizionamento della billetta in fase di abbozzatura rispetto alla posizione originaria. Si nota Fig. 11 - Influenza della variazione di posizione della billetta in fase di abbozzatura sulla forza di stampaggio nella fase di abbozzatura e sulla fase di finitura. Individui che soddisfano i vincoli come la forza di stampaggio risulta essere non correlabile alla variabile posizionamento, infatti la billetta ricalcata posizionata sullo stampo inferiore di Parametri di ottimizzazione abbozzatura tende sempre a “scivolare” verso la parete di ap• Lunghezza billetta = min 94% lunghezza originale, corripoggio perdendo la variazione di posizionamento. I risultati dispondente a una riduzione massima di peso di 2 kg. mostrano come la convergenza dell’algoritmo MAES porti ad una • Posizionamento billetta: traslazione massima 15,5 mm lungo soluzione soddisfacente in cui il vincolo di riempimento è sodasse X (Xg = -2mm). disfatto dopo la prima generazione dell’algoritmo, e le generazioni successive permettono di minimizzare l’acciaio impiegato L’algoritmo MAES è stato organizzato con una popolazione di 10 e di minimizzare la forza impiegata nelle fasi di Abbozzatura in famiglie di 4 individui ciascuna, per un totale di 40 casi di commaniera significativa e di Finitura in misura minore (Fig12). In binazioni. Ogni combinazione prevede lo sviluppo di tutto il proquesta fase gli stampi accolgono tutto l’abbozzato andando a cesso di forgiatura e quindi le varie fasi di Ricalcatura, contatto con lo stesso direttamente sulla bava, il materiale in Posizionamento billetta ricalcata nella fase di Abbozzatura, deformazione è costretto a riempire, ma non può fluire verso Abbozzatura e Finitura, per un totale di 160 simulazioni complel’esterno. Le cavità degli stampi sono già completamente riemte di forgiatura. pite quando al cinematismo mancano ancora 3,5 mm di corsa, durante la quale il carico della pressa non aumenta, vista la suRisultati perficie ormai tutta in presa, bensì aumentano gli sforzi di traL’interfaccia grafica di visualizzazione dei risultati del codice zione massima sugli stampi nella sezione in cui si innesca la numerico utilizzato è estremamente intuitiva, attraverso rancricca. Tale ultimo risultato, unitamente alla deformazione e king dei diversi casi, permette di valutare immediatamente la riempimento visualizzabile step by step, ha posto le basi di imsoluzione migliore. Il ranking viene organizzato in maniera auplementazione di ottimizzazione successiva: partendo dalla sotomatica mediante una funzione di costo, che valuta il rispetto luzione migliore di prima ipotesi ed indagando un range di vadei vincoli inseriti ed il risultato ottenuto in termini di miniriazione del volume iniziale della billeta che minimizzasse ultemizzazioni richieste. Analizzando i numerevoli risultati prodotriormente il risultato ottenuto, ed aggiungendo ad essi una difti, automaticamente si riesce a distinguere, in verde, i setup che ferente geometria del preformato di Abbozzatura. hanno rispettato i vincoli di processo imposti, cioè il completo La nuova fase di abbozzatura studiata prevede un prodotto pririempimento e l’assenza di difetti nei volumi ove ciò è richievo di bava, la forma è molto meno vicina al finito di stampagsto, dalle soluzioni in arancione in cui le impostazioni non sogio, quindi più intermedia. Questa soluzione registra una noteno sufficienti a soddisfare tali vincoli.
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Newsletter EnginSoft Year 9 n°4 -
vole diminuzione del carico pressa in fase di Abbozzatura, ma anche in fase di Finitura. La modifica al processo, dopo l’analisi di ottimizzazione e le valutazioni delle influenze dei parametri, ha permesso una distribuzione più omogenea degli sforzi e delle deformazioni nelle diverse fasi di processo, studiando una preformatura che permettesse di utilizzare ancor meno materiale (Fig.13), garantendo un completo riempimento ed assenza di difetti nel prodotto finale. Per minimizzare il rischio di rottura duttile nello stampo di finitura è stato accentuato il raggio di raccordo nel punto di innesco (R1) per non favorire la concentrazione localizzata degli sforzi di trazione, gli altri parametri geometrici (R2 ed L1) non sono significativi, così come la temperatura iniziale (T1) dello stampo perché bassa, mentre è da monitorare la temperatura finale (T2) perché ad un suo aumento corrisponde una maggiore deformabilità del materiale fino a valori critici.
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Fig. 12 - a) Diverso posizionamento in fase di Abbozzatura. b) Contatti e riempimento in Finitura del Caso Iniz. e del Caso Ott. c) Carico in Abbozzatura per il Caso Iniz. e per il Caso Ott. d) Carico in Finitura per il Caso Iniz. e per il Caso Ott.
Conclusioni Lo studio condotto sul processo di stampaggio a caldo di acciaio si è incentrato su un’analisi numerico sperimentale, i cui obiettivi principali sono stati l’ottimizzazione del processo prendendo in esame le variazioni dei parametri nei range di analisi; tale approccio ha consentito di dare rigore a quelle soluzioni nel processo in esame che discendevano dalla Fig. 13 - Influenza dei parametri geometrici dello stampo su resistenza a Fatica Termo Meccanica. semplice esperienza degli operatori ed ha con- Risparmio di materiale dopo due studi di ottimizzazione di processo. sentito l’ottimizzazione del ciclo di produzione di un componente di geometria complessa. La modellazione numerica, analizzando i fattori più influenti, ha L’ottimizzazione multi-obiettivo è stata condotta sull’intero prodato l’opportunità di proporre ulteriore minimizzazione del macesso ed i risultati hanno permesso di correlare i principali pateriale e suggerire variazioni delle geometrie degli stampi al firametri di processo ai benefici desiderati ed ottenuti: risparmio ne di avere un prodotto che in fase di finitura richieda una midi materiale (benefit economico) e diminuzione di onerosità di nore drasticità di applicazione del carico pressa, intimamente processo (benefit energetico-economico-ecologico): collegato al fenomeno di rottura degli stampi in quella • Ottimizzazione del materiale: faseL’ottima rispondenza nel confronto numerico sperimentale • -27% di risparmio di materiale scartato dopo Prima ha consentito di desumere l’affidabilità dei risultati forniti, il Ottimizzazione che potrà portare alla possibilità di migliorare cicli già esisten• -49% di risparmio di materiale scartato ti, ma anche di progettare nuovi componenti e cicli di produziodopo Seconda Ottimizzazione ne con vantaggi in termini di tempo ed economici. La sperimen• Ottimizzazione del carico pressa pari a: tazione virtuale non è più considerata come una fase di test vol• 1399 T fase di abbozzatura: - 24 % dopo Prima ta a verificare se l'implementazione pratica di un nuovo procesOttimizzazione so/prodotto risponde effettivamente agli obiettivi fissati in fa• 1200 T fase di abbozzatura: - 31,4 % dopo se di progettazione. Essa apporta valore aggiunto se pensata Seconda Ottimizzazione non solo come conferma di quanto previsto ma soprattutto co• 1500 T fase di finitura: - 4,2 % dopo Prima me potenziale fonte di opportunità di miglioramenti non intuiOttimizzazione bili a priori. • 1400 T fase di abbozzatura: - 10,4 % dopo A.Pallara - EnginSoft, Seconda Ottimizzazione Y.Cogo, S. Mazzoleni - Feat Group • Assenza di difetti e di ripieghe nella soluzione ottimizzata. Per ulteriori informazioni: • Completo riempimento in fase di finitura della soluzione Marcello Gabrielli, EnginSoft ottimizzata. [email protected]
Case Histories
40 - Newsletter EnginSoft Year 9 n°4
Nella International CAE Conference si è tenuto il Meeting Italiano degli utilizzatori di Forge Il 23 ottobre, all'interno della International CAE Conference, il centro di competenza simulazione di processo - forgiatura di Enginsoft ha voluto invitare tutti gli utilizzatori del software Forge/ColdForm per una sessione di aggiornamento sui prodotti. Transvalor, la casa produttrice del software, ha voluto essere presente con il dott. Jean Fourniols e l'ing. Laetitia Pegie, che hanno illustrato la roadmap di sviluppo dei prodotti e suggerito il 'modus operandi' di utilizzo. L'incontro, al quale hanno assisitito una quarantina di persone, ha visto protagonisti anche alcuni utenti, che hanno presentato il proprio lavoro: l'ing. Sartori di Muraro-Stipaf (nella foto) ha raccontato come intere linee di laminazione circolare vengono progettate in virtuale, tenendo conto di tutte le fasi e della metallurgia del materiale, l'ing. Pallara di Enginsoft ha mostrato un caso pratico di ottimizzazione di una forcella in acciaio stampata a caldo da FEAT
Group, il dott. Michele Francesco Novella del DII - Università di Padova ha mostrato come è possibile prevedere l'evento di frattura duttile nello stampaggio a freddo ed infine l'ing Inaki Perez di Tecnalia ha illustrato come nei laboratori spagnoli si utilizzano questi strumenti per simulare il complesso processo di rotary forging. I partecipanti hanno potuto apprendere informazioni utili per l'uso quotidiano di Forge e ColdForm, ma soprattutto conoscersi e scambiarsi consigli su come far rendere al meglio questi strumenti. Il centro di competenza di Enginsoft sulla forgiatura (in foto da sinistra a destra l'ing. Andrea Pallara, l'ing. Marcello Gabrielli e l'ing. Federico Fracasso) ha nelle pause approfondito tematiche individuali, con il supporto di Transvalor. Appuntamento per tutti all'edizione numero 10 dell'Italian Forge Users' Meeting, nel 2013. Per ulteriori informazioni: Marcello Gabrielli, EnginSoft [email protected]
Events
EnginSoft al Convegno AIM di Trento Dal 7 al 9 novembre si è svolto a Trento il 34° Convegno Nazionale di A.I.M. (Associazione Italiana Metallurgia), che ha visto la partecipazione di oltre 300 persone provenienti sia dal mondo universitario e della ricerca, che dal mondo industriale. Enginsoft ha voluto essere presente a questo importante evento in una duplice veste, come sponsor e portando dei contributi scientifici nelle sessioni tecniche. E' stato quindi allestito uno stand, dove si sono alternati Marcello Gabrielli, Piero Parona e Giampietro Scarpa, che hanno dato informazioni in merito alle diverse attività di simulazione e di ottimizzazione che Enginsoft è in grado di affrontare. Per le sessioni tecniche, Marcello Gabrielli ha presentato nella sessione Acciaieria un lavoro di ottimizzazione condotto in collaborazione con FEAT Group dal titolo 'Studio di fattibilità produttiva attraverso simulazione numerica', mentre Giampietro Scarpa ha illustrato nella sessione Pressocolata, che ha visto come chairman Piero Parona (Presidente del Centro di Studi Pressocolata di AIM) il lavoro 'Analisi delle difettologie nel processo di pressocolata: contributo della simulazione numerica'.
Enginsoft è stata invitata a tenere una lezione al Corso di 'Siderurgia e fonderia' del 5° anno Corso di Laurea Magistrale in Ingegneria dei Materiali. Il 20 novembre l'ing. Marcello Gabrielli è stato invitato dal prof. Giovanni Staffelini a tenere una lezione agli studenti del 5° anno di Laurea Magistrale dell'Università di Trento - Facoltà di Ingegneria del Materali. La lezione ha riguardato una panoramica dei processi di solidificazione in lingottiera e di colata continua, affrontati dal punto di vista della simulazione numerica. Il docente ha illustrato quanto sia difficile definire un materiale per questo tipo di simulazioni, per poter ottenere dei risultati prossimi alla realtà produttiva. La presentazione di alcuni casi reali ha stimolato la discussione in aula e l'interesse dei ragazzi, che hanno visto applicate nella pratica le nozioni apprese durante il loro percorso di studi. Sono emersi anche alcuni temi di interesse, che saranno approfonditi in prossimi lavori di tesi, nei quali la simulazione potrà avere un ruolo importante.
Newsletter EnginSoft Year 9 n°4 -
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Multidisciplinary optimization for a IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform INTRODUCTION TO THE RUBEECOMP PROJECT THE OBJECTIVES RuBeeCOMP is a research project co-funded by the Regione Toscana (Italy) in the frame of the POR CReO funding program.
which were installed into the vehicle as illustrated in the concept picture in Figure 1, enable these measurements. The main objective of the RuBeeCOMP project is to define the best possible configuration for the composite structure and the wireless tag. For the specific work and the required data, a numerical platform was developed that coordinates both, the geometrical/functional parameters of the tag and the composite laminate. The technological platform was developed in order to integrate the data obtained during the project’s preliminary phases and from the parametric FE models, to achieve the best configuration for the executive design.
Fig. 1 - Simulation of a submarine mission for the inspection of the seabed
The aim of the project is to study, test and assess materials, systems, technologies as well as design methodologies for the manufacturing of composite material components. Wireless communication systems able to operate in radiofrequency unfriendly environments, such as oil or water, are also included in the study and project activities. At first, the composite demonstrator with the wireless communication system has been installed into a submarine vehicle, which is able to explore the seabed and to monitor the submarine environment by performing optical and sound surveys, and physical and chemical analyses. Suitable sensors
Fig. 2 - 3-point-bending test realized on composite virgin and aged specimens
Fig. 3 - Environment tests on composite specimens containing the wireless tag (a) and electromagnetic setup of the communication systems (b)
Research & Technology Transfer
42 - Newsletter EnginSoft Year 9 n°4 The five main Project “Work Packages” completed during the last two years allow to define the optimum solution for the technological demonstrator realized, guaranteeing the highest achievable level of performances in terms of structural and electromagnetic response.
Fig. 5 - Structural FE model developed in ANSYS Mechanical and ANSYS ACP environments
EXPERIMENTAL ANALYSIS Once the functional requirements of the wireless tag and the whole vehicle are defined on the base of mission length, depth and velocity expected and amount of information collected, a preliminary study of the vehicle geometry is carried out, of Fig. 6 – Draping and Flat Wrap analysis realized in ANSYS ACP on the rear double-curved surfaces the candidate wireless communication systems and of a set of candidate composite laminate, several full parametric models are realized using an materials through a rich experimental campaign. On the hybrid approach (numerical and empirical) verified within composite materials chosen, a set of physical and mechanical ANSYS Maxwell and ANSYS HFSS simulation environments. The tests are realized on virgin and aged specimens, with or main variables evaluated for the electromagnetic issue are without the wireless tag. magnetic field and inductance, functions used hereinafter in the optimization environment to select the best allowed configuration. The first model represents the prototype of an antenna with a 42mm radius multi-turn coil made of 33 loops of a copper wire (section radius equal to 0.25mm). The second model is a multi-turn printed loop on a 0.8mm thick FR4 laminate. The CPW fed antenna is made of 16 properly distanced 0.6mm wide microstrip copper line turns. The background scenario was modeled by imposing radiation boundaries to the problem region in order to simulate free emission into space. In the operational environment, the latter could be a lossy and/or conductive media like sea water Fig. 4 - Electromagnetic F models developed in ANSYS HFSS simulation or oil and it should be consequently modeled with the environment correspondent electric characteristics. To evaluate the established communication degree, two different multi-turn tags are tested: a 33-turn copper wire coil STRUCTURAL MODELS and a multi-turn microstrip coil. All the composite specimens The numerical platform developed for the RuBeeCOMP research are tested through thermal and moisture loads, structural project allows to maximize the structural and electromagnetic loads (time-increasing distributed pressure, bending), performances through suitable optimization tools, analyzing vibrations and shockproof, monitoring internal and external custom FE models built in ANSYS environment. The damages using an ultrasound waves control. The tests realized technological demonstrator’s geometry, containing the allow to make an accurate mechanical characterization of the wireless communication system, is defined during the first composite materials, analyzing the electromagnetic preliminary study on the base of the results obtained through performances of the multi-turn tags and the agreement fluid-dynamic analysis. Once the demonstrator’s geometry is between communication systems and composites as well. defined, it is imported and analyzed within the platform using the ANSYS code and in particular its ACP module - ANSYS ELECTROMAGNETIC MODELS Composite Prep/Post – which represents the most suitable tool to evaluate the whole composite structure’s performances. The The IEEE 1902.1 “RuBee” communication standard defines the ACP’s features allow to manage in an efficient and flexible way air interface for radiating transceiver radio tags using long all the pre and post-processing phases, evaluating the wavelength signals, up to 450 kHz. These devices have a very industrial feasibility according to the assumed production low power consumption (a few microwatts), they operate over process (ACP’s Draping & Flat wrap functions). Moreover, other medium ranges (0.5 to 30 meters) and at low data transfer specific features allow to verify damage conditions deriving speeds (300-9600 bps). To design and optimize the from in-plane and out-of-plane stress distributions, through communication systems dipped in a multi-layer composite
Research & Technology Transfer
Newsletter EnginSoft Year 9 n°4 -
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interface to build the laminate’s stacking sequence for each design during the optimization process. Through this interface the definition of the laminate layup is driven by a customized algorithm that allows to create a symmetric and balanced laminate, using practical engineering rules based on sublaminate approach, in order to guarantee an easy implementation from the production point of view. In this way the problems caused by technological effects are completely deleted, avoiding the need to insert any constraint after the definition of the composite layup within the optimization process.
Fig. 7 – Sub-laminate approach used by ESAComp-modeFRONTIER interface for the definition of the laminate’s stacking sequence for each optimization design
PLATFORM USER INTERFACE In order to create an accessible and easy-to-use technological platform and a comprehensible multidisciplinary design procedure, a Java language user interface is created through a customization focused on the logical procedure and on the specific electromagnetic and structural issues studied. When using the user interface, the designer does not need to edit the programming code manually; the code allows to manage automatically the numerical FE models, the input variables, the objective functions and the file transfers. Through the interface, the user can edit the ESAComp composite materials
customized multi-failure criteria, such as Max Stress, Max Strain, Tsai Wu, Tsai Hill, Puck 2D/3D, Hashin 2D/3D, LArC, Cuntze and so on. During the platform and user interface development, the debugging of the platform that implements the design procedure is realized using a simplified geometry in which the wireless system is contained. Once the main platform requirements are obtained in terms of effectiveness, efficiency and flexibility, its robustness and accuracy are evaluated analyzing the whole prototype structure. The technological platform allows to study the mechanical behavior of the submarine vehicle optimizing the performances, according with the objective functions related to structural stiffness and Fig. 9 – Analysis of results obtained through advanced post-processing tools in modeFRONTIER environment strength. EFFICIENT LAMINATE DEFINITION PROCEDURE One of the main results obtained during the development of the project is the processing and implementation of the ESAComp-modeFRONTIER interface within the technological platform. Within the design procedure, ESAComp fulfills the role of a library, in which the composite material data collected from the experimental campaign are contained. The material library is used by the ESAComp-modeFRONTIER
library, some geometrical and functional parameters of the wireless tag, the technological demonstrator’s geometry and the loads and constraints operating conditions. The platform allows to obtain the best solution maximizing or minimizing the objective functions linked with the structural performances considering several load cases at the same time.
Fig. 8 – User interface and modeFRONTIER workflow that manage the information and the variables of the numerical platform’s logical flow
MULTIOBJECTIVE AND MULTIDISCIPLINARY OPTIMIZATION Once all the main design parameters are defined by the interface, the numerical platform applies the implemented design procedure working independently. The information present in the material library are used to define for each design the laminate’s stacking sequence with the rules set in the ESACompmodeFRONTIER interface; the current composite laminate configuration is translated and exported for the next
Research & Technology Transfer
44 - Newsletter EnginSoft Year 9 n°4 realized, a final experimental campaign on the whole structure has been achieved to verify the quality of the electromagnetic signal within an unfriendly environment. The dissemination activities have brought a high visibility and prestige to the partial and final results obtained: the work progresses have been presented in dedicated sessions at the “International CAE Conferences” in 2009, 2010 and 2011. At this year's International Conference, the final results have been presented during the “Composite Session” where the presenters showed the technological demonstrator in a dedicated space within the ESAComp stand. Fig. 10 – Experimental tests realized on technological demonstrator in unfriendly environment
steps, represented by ANSYS HFSS (for the electromagnetic analysis) and ANSYS ACP (for the structural simulations). The numerical models built are solved and evaluated based on the strength of the objective functions’ values obtained, then available modeFRONTIER post-processing features allow to classify the results with multidimensional diagrams and charts. For the RuBeeCOMP research project, the postprocessing tools allow to evaluate the electromagnetic response of the multi-turn printed tag dipped in the fiber-
Fig. 11 – Exhibition of technological demonstrator at International CAE Conference 2012
reinforced composite laminate and the fiber-reinforced composite laminate and the structural performances of the technological demonstrator in several operating load conditions. In this case the objective functions are represented by the antenna inductance (L), magnetic field intensity (H), weight of the structure (W), displacements (D), Inverse Reserve Factor distribution (IRF). The information collected through the experimental campaign, preliminary design analyses and the results obtained through the platform, allow up to identify the best configuration to realize the executive design. CONCLUSIONS AND DISSEMINATION ACTIVITIES The RuBeeCOMP research project carried out during the last two years has enhanced the already robust relationship between EnginSoft, WASS and IDNOVA. The most important result is the production of the technological demonstrator, according to the executive design, containing the wireless communication system integrated within the composite demonstrator component. Once the demonstrator has been
Research & Technology Transfer
For more information: Fabio Rossetti, EnginSoft [email protected]
Meeting conclusivo del progetto 'RuBeeCOMP' Il Competence Center fiorentino di EnginSoft ha ospitato il ‘meeting’ conclusivo del progetto 'RuBeeCOMP' – attività di ricerca finanziata dalla Regione Toscana nelle modalità del programma POR CReO 2007-2013. Obiettivo principale della indagine tecnica è lo sviluppo di metodologie finalizzate alla progettazione integrata prodotto-processo per la realizzazione di componenti in materiale composito, caratterizzati da sistemi di comunicazione wireless; quest’ultimi sono concepiti al fine di operare correttamente in ambienti ostili alla radiofrequenza, come ad esempio l’acqua, l’olio, ecc. Il sistema RuBeeCOMP costituirà elemento principale di eccellenza dell’allestimento tecnologico della piattaforma AUV (Automonous Underwater Vehicle) denominata V-Fides Progetto di Ricerca al quale partecipa anche EnginSoft – e destinato alla gestione delle comunicazioni da e verso la piattaforma di lancio in acqua e/o a terra. Al sistema è infatti deputato l'onere di ricevere le informazioni dalla base, quindi la trasmissione alla stessa dei dati raccolti dal drone nel corso della missione subacquea finalizzata ad operazioni di detezione, esplorazione del fondale marino EnginSoft ha contribuito al progetto in modo poliedrico; lo sforzo tecnico spazia infatti dalla progettazione e simulazione dell’antenna di trasmissione/ricezione all’ottimizzazione del processo di produzione del supporto in materiale composito. All’incontro hanno partecipato tutti i partner che hanno collaborato allo studio e alla realizzazione del progetto: Whitehead Sistemi Subacquei (Wass), IDNova ed EnginSoft; inoltre alla riunione erano presente l’ing Vittorio Falcucci, attualmente Direttore tecnico di Eurotorp ma all’inizio dell'attività mentore e fortissimo sostenitore in Wass della liceità e delle prospettiche aspettative positive del progetto stesso e, il Professor Giuseppe Martini quale supervisore designato dalla Regione Toscana: tale ruolo, va detto, è stato interpretato in forma progressiva e stimolante, sicuramente percepibile nel corso dei meeting per la puntualità e la competenza dei chiarimenti tecnici richiesti.
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Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 La nuova release 14.5 di ANSYS Workbench, uscita a Novembre 2012, presenta numerose novità utili nella quotidianità delle applicazioni ingegneristiche. In particolare, analizzando l’ambiente Mechanical, si possono individuare diverse nuove funzionalità, sia per quanto riguarda la gestione della geometria, la generazione della mesh, la definizione dei contatti, che per quanto riguarda la soluzione vera e propria del problema e il post-processamento dei risultati. Si accenna qui alle più importanti novità rinviando i lettori interessati al servizio di assistenza tecnica EnginSoft per gli approfondimenti. Per quanto riguarda la geometria, è possibile ottenere in DesignModeler, modelli di più rapida gestione sia in fase di importazione che in fase di Fig. 1 - Gestione della geometria fino a 10 trasferimento a volte più rapida Simulation (velocità fino a 10 volte superiore per modelli di grandi dimensioni!). Questo è reso possibile dal fatto che la conversione a Parasolid non avviene più al momento dell’importazione dell’intero assieme come avveniva nelle release precedenti, ma solo al momento in cui si definiscano in DesignModeler delle modifiche alla geometria, e solo limitatamente alle zone interessate da tali modifiche (fig.1) Riguardo ai contatti, una “matrice dei contatti” configurabile consente una miglior comprensione delle connessioni tra le parti. Tale matrice è completamente personalizzabile e consente di gestire sia contatti veri e propri, che connessioni generiche quali spot weld, joint e spring. E’ possibile inoltre evidenziare i contatti presenti solo su un singolo corpo o su una named selection, in modo da facilitare la comprensione delle connessioni anche per assiemi complessi (fig.2).
Fig. 2 - Matrice dei contatti
Al fine di facilitare la leggibilità di modelli complessi, sono disponibili nella nuova release sia filtri basati sul nome dei componenti o delle named selections, sia la possibilità di utilizzare colori diversi in maniera random per plottare diverse condizioni di carico, vincolo, diverse named selection così da renderle facilmente identificabili (fig.3).
Fig. 3 - Colori random per il plottaggio di named selections
Per semplificare l’imposizione di condizioni al contorno o di carico simili, quasi tutti gli oggetti inseribili in Simulation possono essere riprodotti e copiati secondo diversi pattern, mantenendo però inalterati i dettagli dell’oggetto originario. E’possibile copiare in questo modo, per esempio, l’imposizione del medesimo precarico su un insieme di viti o ripetere gli
Software Update
46 - Newsletter EnginSoft Year 9 n°4
Fig. 4 - pattern di bolt pretension
stessi controlli di mesh su corpi simili (fig.4). Eseguire sub-model consente di risparmiare tempo quando si è interessati a ciò che accade in dettaglio su una porzione del modello. Oggi in WB è completamente implementata la procedura di sub-model per modelli 3D, in via completamente nativa. La rimappatura degli spoFig. 5 - Vantaggi derivanti dall’utilizzo della stamenti nelle zone di tecnologia GPU taglio non è eseguita con comandi APDL ma attraverso procedure interne a WB, e ciò consente di utilizzare le potenzialità di rimappatura già implementate per l’importazione di carichi ottenuti da solutori esterni (coefficienti convettivi, forze, temperature di bulk,..). Per quanto riguarda la fase di soluzione, il metodo “sparse solver” adesso può utilizzare GPU multiple al fine di ridurre il tempo di soluzione (fig.5). Per ridurre le dimensioni dei file dei risultati ottenuti durante il run, inoltre, la memorizzazione di essi viene effettuata a singola precisione per quanto riguarda le grandezze derivate, come le tensioni e le deformazioni (variabili di elemento). Per lo stesso motivo, le tensioni principali non vengono salvate nel file dei risultati, ma vengono rivalutate qualora se ne richieda il plot come quantità di post-process. In questo modo si riescono ad ottenere file di risultati fino al 50% più piccoli rispetto al passato. Per modelli con geometria ciclica, al fine di minimizzare lo spazio di memoria richiesto in fase di plottaggio, i risultati possono essere mostrati ed animati su una frazione di tutto il corpo simmetrico, scegliendo il numero di settori che si vogliono visualizzare. Spesso è utile inserire carichi o vincoli particolari, che possono essere presen-
Software Update
ti in numerose analisi che si vogliono impostare, come opzione dell’ambiente di simulazione. Nuovi carichi e condizioni al contorno possono essere aggiunti ad ANSYS- Mechanical tramite il nuovo modulo di personalizzazione ACT (per esempio condizioni al contorno acustiche). E’ possibile inoltre creare risultati personalizzati, come ad esempio il plot di criteri di massimo ammissibile basati su un rapporto di tensioni vs una proprietà del materiale, e inserirli nell’albero come un qualsiasi risultato standard. E’ possibile, sempre grazie ad ACT, utilizzare WB per lanciare solutori esterni o inserire add-on esterni nell’interfaccia Mechanical. E’ spesso necessario indagare, possibilmente in modo semplice, le conseguenze di cricche che compaiono in un componente a causa del processo di manifattura o a causa della fa-
Fig. 6 - effetto della presenza di una cricca in un sub-model
tica, al fine di evitare rotture premature dello stesso. Nella nuova release 14.5 cricche ellittiche possono essere inserite in geometrie nominali importate in WB, semplicemente definendo un centro di posizionamento associato ad un sistema di riferimento e le dimensioni della cricca che si vuole rappresentare. La mesh è quindi gestita automaticamente dal software senza la necessità di ulteriori azioni da parte dell’utente. I parametri di cricca (K1 per il modo 1, K2, K3, Stress intensity factor, Mixed mode J-integral, …) possono essere postprocessati e visualizzati lungo il path che segue il fronte della cricca, al fine di agevolare la comprensione dei risultati. Una cricca può essere introdotta anche all’interno di un submodel per ridurre il tempo computazionale totale e allo stesso tempo incrementare l’ accuratezza locale dei risultati ottenuti (fig.6). Si ricorda che è sempre possibile trovare informazioni relative alle novità inserite nella release 14.5 all’interno dell’help sotto la voce “Release Notes”. Per maggiori informazioni: Valentina Peselli - EnginSoft [email protected]
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Simulating Gear Pairs within SIMPACK
SIMPACK, a Multi-Body Simulation software tool, enables complete mechatronic systems which include high fidelity drivetrains to be accurately simulated. The individual forces acting between the gear wheel teeth can be easily visualized with force arrows and plotted. The SIMPACK Gear Pair element enables full three dimensional behavior such as dynamically changing angular and radial misalignments to be investigated. HISTORY Fig. 1 - Bevel gear with crowning Initially developed for Formula 1 high performance engines back in 2003 (by Lutz Mauer, an used for achieving the optimum balance between solver executive board member of SIMPACK AG), the SIMPACK speed and accuracy. For example, simple one-dimensional Gear Pair functionality has since been used in a large elements may be used for torsional analyses whereas variety of industrial sectors, e.g. automotive, wind, rail, gearbox elements (e.g. planetary gear stage) may be used shipping, aerospace, concrete mills, material handling, for more detailed analyses when reaction moments on the etc. housing are required. For simulations where individual tooth contact forces are required, the SIMPACK Gear Pair GENERAL force element, FE 225, may be used. This element enables the additional analyses of the meshing forces and In SIMPACK, a large variety of elements are available for moments, shaft bending, bearing forces, and a host of the simulation of torque converters. Depending upon the task at hand, elements of various level of detail may be other pertinent analyses (Fig. 2). Gear Pair FE 225 is an analytical element, and therefore, extremely fast simulation times can be achieved. Graphical primitives are defined for the gear wheels which are subsequently used for the force calculations. This results in accurate animation of the gear tooth contacts and play. The Gear Pair FE 225 includes the following: Gear Types: • Involute spur • Helical • Ring • Rack and Pinion • Bevel
Fig. 2 - Gear box with Gear Pair forces and other resultant forces
Input: • Profile Shift • Backlash
Software Update
48 - Newsletter EnginSoft Year 9 n°4 All modification types can be input for the right and left flanks or for both together.
Fig. 3 - Motion of floating sun within a planetary stage (© IMM, TU Dresden)
GEAR PAIR FORCE ELEMENT HIGHLIGHTS For simulating gear pairs with non-parallel axes, “slicing” of the gear wheel contact area is necessary. This is achieved by setting a single parameter (i.e. “Number of slices”) within the gear pair force element. The handling of the offset angles for helical gears is now fully automatic. Slicing is also necessary if flank modification is used. Shuttling forces, i.e. the axial displacement of the contact forces, is included. In the case of helical gears, this will result in an additional tilt moment. Users can easily switch on and off, and choose between, various output value types. This enables easier handling and a more efficient use of data storage space. The different types of output are described below. GEAR PAIR DATA CHECK In order to check the input parameters and initial conditions of the gear pairs within a model, a user can perform a “Test Call”. This will result in a list being generated for each gear pair consisting of important input parameters and calculated data. Information such as the theoretical center distance, radial offset, axial offset, transverse contact ratio, overlap ratio, and total contact ratio will now be readily available.
Fig. 4 - Bevel gear primitives
• Viscous and Coulombic damping • Tooth profile and flank modification. Simulated Behavior: • Meshing frequencies • Shuttling forces • Dynamically changing misalignments (radial and angular). GEAR PAIR PRIMITIVES For all gear pair types, tooth and flank modification is available. The modifications are primarily used for smoothing the non-linear internal excitations due to the continually changing number of teeth in contact. The following modification types have been added: • Tip (Fig. 5) • Root • Circular • Left and Right Side • Lead Crowning (Fig. 6) • Input Function Array
GEAR PAIR OUTPUT VALUES By way of parameterization, a user can choose for which gear pairs the “Basic Output Values” will be generated. These values include such data as the relative angles and angular velocities, “total normal contact stiffness” and the “dynamic transmission error”. Similarly, a user can also choose which “Advanced Output Values” are to be saved (Fig. 8). These values are primarily used for analyzing the coupling forces of the gear pairs, either for the sum of all teeth in contact or the individual tooth-pair contacts. In addition the “Advanced Fig. 5 - Tip profile modification Output Values” enable easy animation of the force arrows in the PostProcessor (Fig. 9). After an integration run is complete a user can subsequently choose which output values to generate. Re-running the time integration is not necessary. Only re-performing “measurements” is required.
Fig. 6 - Crowning, left and right flank
Software Update
CONCLUSION The SIMPACK Gear Pair Force Element is an important component in the analysis of drivetrains. Full three
Newsletter EnginSoft Year 9 n°4 -
dimensional non-linear dynamic behavior can be investigated. Customer specific tooth profile and flank modification enables accurate simulation of meshing frequency excitations. Easy animation and plotting of contact forces accelerates comprehension of the dynamic non-linear behavior. Although major milestones in the development of the SIMPACK Gear Pair element have already been achieved, further development will continue to be implemented, enabling the Gear Pair to fulfill the even more demanding customer requirements of the future.
For more information: Fabiano Maggio, EnginSoft [email protected]
Fig. 7 - Rack and pinion gear
Fig. 8 - User choice for advanced output values
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TechNet Alliance Fall Meeting 2012 26th -27th October, Kassel - Germany The Fall Meeting of the TechNet Alliance, one of the world's largest networks of engineering solution providers, has taken place at the Schlosshotel Bad Wilhelmshöhe in Kassel on the last days of October. Apart from the many interesting lectures, the leading theme of the meeting was a full immersion into the HPC environment for technical computing. To update the audience from around the world on the latest developments in this area, three exciting presentations were delivered: 1. Herbert Güttler from MicroConsult provided a detailed history of HPC and a comparison chart which allowed the delegates to “travel” through the years, various versions and hardware of HPC and GPU performances in ANSYS. 2. Dejan Milojicic from Hewlett Packard spoke about his comparisons of different commercial cloud computing solutions for true HPC calculations in the engineering market. 3. Johannes Heydenreich, PhilonNet Engineering Solutions, presented his company’s experiences in setting up a remote cluster utilization at the University of Athens. Mr Güttler’s speech was an extremely deep analysis of multi GPU performances on single and multi-node clusters. It covered a very complex benchmark which was impressive in terms of its good scaling results in the thermo-elastic-plastic mechanical scenario. Already during the presentation, it became clear that it would be quite time consuming to carry on the work. Key points of the presentation where, among others, the speed performances of releases 14 and 14.5 on the new Intel platforms E5-26XX (due to compiler optimized code) and GPU/CPU scaling in both the PCG and Direct Matrix Solver. Dejan Milojicic presented a wide spectrum of benchmarks performed on commercial cloud computing services with respect to performances of multi-core scientific (chemical and number crunching) calculations. The findings were, as a professional user would expect, the following: - Commercial real HPC cloud computing can only be delivered by a limited number of providers - All web offers are only able to provide, in most cases, 4 cores and no real high speed interconnection. - True HPC for scientific computing has to be provided by specialized companies. Mr Heydenreich’s brief presentation was about the real use case of setting up a remote visualization for scientific computing at the University of Athens. He presented web components that have been chosen to deliver services to students and professors on a centralized cluster system for both calculation and visualization.
Fig. 9 - Animation arrows of normal loads “Indiv. load (fl_n) i,k”
For more information: Gino Perna, EnginSoft - [email protected]
Software Update
50 - Newsletter EnginSoft Year 9 n°4
ENGINSOFT coordinates the new “MUSIC” European Project
After a long procedure, the “MUSIC” project times, and shorter intervals between (the acronym stands for: “Multi-layer successive generations of products. control & cognitive System to drive a metal Therefore, MUSIC is strongly aimed at and plastic production line for Injected leading EU-HPDC/PIM factories, for a Components”) has finally received the cost-based competitive advantage positive approval of a technical and through the necessary transition to a scientific Committee. The decision-makers demand-driven industry with lower waste are responsible for selecting Collaborative generation, higher efficiency, robustness IP Projects in the FoF-ICT sector (Factory of and minimum energy consumptions. The Future and Information & Communication Fig. 1 - MUSIC PROJECT LOGO development and integration of a Technologies) applied to energy-aware, completely new ICT platform, based on agile manufacturing and customization. an innovative Control and Cognitive system linked to real time The core concept of the project focuses on the result of the monitoring, allows an active control of quality, avoiding analysis and the possible improvements that can be achieved defects or over cost by directly acting on the process-machine and applied to the two most representative large-scale variables optimization or equipment boundary conditions. The production-lines in the manufacturing field: High Pressure Die Intelligent Manufacturing Approach (IMA) works at machineCasting (HPDC) of light alloys and Plastic Injection Moulding mould project level to optimize the production line starting (PIM). Both are of strategic importance to the EU industry from the management of manufacturing information. An which is largely dominated by SMEs. Intelligent Sensor Network (ISN) monitors the real-time Due to the high number of process variables involved and the production acquiring the multi-layers data from different non-synchronization of the process control units, HPDC and devices and an extended meta-model correlates the input and PIM are most “defect-generating”. Moreover, “energy sensors data with the quality indexes, energy consumption consumption” processes in the EU industries provide less cost function. Data homogenization, centralization and flexibility to any changes in product and process evolution. synchronization are the key aspects of a control system to Owing to both of these factors, sustainability requires that collect information in a structured, modular and flexible machines/systems are able to efficiently and ecologically database. support the production with higher quality, faster delivery Process simulation, data management and meta-models are the key factors to generate an innovative Cognitive system to improve the manufacturing efficiency. The MUSIC project is an FP7 European project that introduces new ICT technologies at manufacturing plants with introduces significant potential impacts: (i) it can strengthen the global position of the European manufacturing industry; (ii) it can create a larger European market for advanced technologies such as electronic devices, control systems, new assistive automation and robots; (iii) it improves the intelligent management of manufacturing information for customization and environmental friendliness. The MUSIC project’s final target is the transformation of an extremely conventional manufacturing sector such as HPDC of light alloys and PIM of polymers into an Intelligent Manufacturing System, capable of zero-defect production, Fig. 2 - MUSIC core concept
Research and Technology Transfer
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Fig. 3 - MUSIC project structure in EUCOORD
energy saving and cost reduction. The achievement of this target passes through multi-level objectives, contributing to a knowledge-based and dynamic management of HPDC/PIM manufacturing data. The MUSIC Project started on September 1st, 2012 and will run for 4 years, under EnginSoft Coordination and Management, with more than 9 million Euros of costs, two thirds funded by the European Commission. MUSIC is a fully integrated project, since the Consortium is constituted by 16 complementary European members (ENGINSOFT SPA, ELECTRONICS GMBH, HOCHSCHULE AALEN, MAGMA GMBH, UNIVERSITA DEGLI STUDI DI PADOVA – DTG, FUNDACION TEKNIKER, FUNDACIO PRIVADA ASCAMM, OSKAR FRECH GMBH CO KG, TOOLCAST SNC, MAIER, S.Coop. AUDI AKTIENGESELLSCHAFT, RDS MOULDING TECHNOLOGY SPA, MOTUL SA, REGLOPLAS AG, FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V, ASSOMET SERVIZI S.R.L) which cover with their different activities and know-how, the entire value-chain, from RTD to demonstration, from prototyping to standardization, as described in the 8 work-packages into which the project is subdivided. For a more efficient and easy management of the project, EUCOORD is proving a very useful tool, since it is a web-based collaborative tool specifically designed for Project Management and Financial Accounting. It assists Coordinator and Partners in keeping the project on track, allowing project structure handling (details on Workpackages, Tasks, Milestones, Deliverables, in terms of technical content, leadership, duration and deadlines), correct data collection (partners information, profiles, contacts, detailed activities assignment with related resources), accounts management (inputs of costs and effort provided by partners are stored and validated by the coordinator), reports generation and disseminations planning, web-site creation, management and customization, including also a passwordprotected area for internal communication and document sharing, also of confidential nature. The starting point of the project was marked in Vicenza, on September 17th and 18th 2012, when the Kick-off Meeting took place. A group of 60 people representing the 16 partners engaged in the project, gathered at the University of Padova located in Vicenza, for a two-day meeting. The meeting content was articulated in three different sessions aiming respectively at:
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1. Analyzing the state of the art of the control for different devices in the production line. 2. Providing attendees with general information concerning management & coordination, communication strategies, project content and structure, partners’ interactions and contributions, responsibilities and duties in compliance with the contract and its annexes. 3. Presenting WP1 tasks and objective so to focus and structure the first RTD objectives to be discussed and performed. The activities performed by now are mainly concentrated in the technical and scientific tasks of WP1 and management (WP8) as well. First project dissemination activities have been promoted so to give visibility to project existence by presenting the public summary and objectives in two different international event, ALUMINUM 2012 (Düsseldorf Messe, 9-11 October 2012) and INTERNATIONAL CAE Conference (Lazise – Verona, 22-23 October 2012). As soon as first results and achievements will be available, further actions will be planned for targeted knowledge transfer and sharing. In this perspective the project has been submitted to NAFEMS World Congress of next year (Salzburg – June 2013). The MUSIC Project web site has been submitted to the European Commission on November
Fig. 4 - The kick-off meeting in Vicenza
15th, 2012. It describes the structure, contents and functionalities of the Project portal: http://music.eucoord.com/ and its connection with the EUCOORD platform for Project Management. This first meeting has been very successful, especially because all of the participants were enthusiastic to start the new challenge and at the same time could share with each other their cutting-edge technologies and knowledge. These exchanges among the partners are fundamental for a positive beginning of the project. The enthusiastic and promising assertiveness is essential for good and profitable results to move from “music” to “symphony” in manufacturing production lines! For more information: Nicola Gramegna, EnginSoft [email protected]
Research and Technology Transfer
52 - Newsletter EnginSoft Year 9 n°4
Modellazione e Progettazione Ottimale di Strutture Ceramiche Un progetto di ricerca e innovazione nell’ambito dei Partenariati e percorsi professionali industria-università Il gruppo di ricerca in Meccanica dei Solidi e delle Strutture del Dipartimento di Ingegneria Meccanica e Strutturale dell’Università di Trento coordina il progetto INTERCER2, finanziato dalla Comunità europea nell’ambito degli IAPP (Partenariati e percorsi professionali industria-università). Il gruppo di ricerca è guidato dai professori Davide Bigoni e Luca Deseri e include tra i suoi componenti il professor Massimiliano Gei e i ricercatori Francesco Dal Corso, Andrea Piccolroaz e Roberta Springhetti. Il progetto INTERCER2 mira ad un approfondimento della conoscenza scientifica del processo produttivo della ceramica, con il duplice scopo di ottimizzare la produzione e sviluppare nuove strategie tecnologiche ed industriali che consentano di ridurre i costi di progettazione e fabbricazione dei componenti ceramici, migliorandone contemporaneamente la prestazione e l’affidabilità. Gli obiettivi verranno raggiunti sia attraverso la modellazione della compattazione delle polveri e del processo produttivo sia mediante lo sviluppo di strutture e materiali ceramici multifunzionali avanzati.
L’industria ceramica è un settore ampiamente consolidato in Europa e le ceramiche avanzate sono cruciali nello sviluppo di nuove tecnologie, con applicazioni alla nanotecnologia; tuttavia la produzione industriale delle componenti ceramiche si basa ancora spesso su processi empirici, non sempre sufficientemente razionalizzati e difficilmente controllabili, con la conseguente generazione di quantità rilevanti di scarti e residui di produzione. Il progetto di ricerca è focalizzato sulla modellazione meccanica, implementazione numerica e simulazione dei processi produttivi, con particolare riguardo alla simulazione dei processi di formatura delle polveri ceramiche, dove il gruppo di Meccanica dei Solidi e delle Strutture ha già un’esperienza ben consolidata. Usando tecniche moderne basate sulla teoria dell’elastoplasticità si è infatti sviluppato un modello costitutivo che, tarato su prove meccaniche con protocollo preparato ad hoc, permette la simulazione di processi di formatura a freddo rendendo possibile la determinazione dello ‘spring-back’, delle distribuzioni di densità, stress residui e delle caratteristiche elastiche interne al pezzo a fine forma-
Fig. 1 - Grafici, da sinistra: distribuzioni di stress residuo, densità di vuoti e modulo di elasticità tangenziale nel componente ceramico a termine del processo di formatura. I risultati sono ottenuti da simulazioni numeriche in cui è implementato un modello costitutivo specifico per le polveri ceramiche compattate a freddo sviluppato dal gruppo di Meccanica dei Solidi e delle Strutture dell’Università di Trento.
Research and Technology Transfer
Newsletter EnginSoft Year 9 n°4 -
tura. Attraverso lo strumento su cui il gruppo di ricerca sta lavorando è possibile ottimizzare la forma dello stampo e la composizione delle polveri per ridurre lo scarto e ottenere pezzi di caratteristiche meccaniche ottimali. Più nel dettaglio, gli argomenti che saranno sviluppati nel progetto di ricerca sono i seguenti: Formatura di polveri ceramiche. Si svilupperanno strumenti per la modellazione e la simulazione del processo di formatura, basandosi su teorie costitutive innovative per la descrizione delle proprietà meccaniche dei materiali ceramici. Tali modelli saranno fondamentali per l’implementazione in codici numerici e la loro applicazione allo sviluppo di nuove e più efficienti tecnologie di produzione. Trattamento di composti ceramici. Una profonda comprensione dell’influenza dei parametri del materiale alla scala micrometrica all’interno del processo permetterà di raggiungere elevati standard di qualità nella produzione e sinterizzazione della ceramica. Miglioramento delle proprietà delle ceramiche. Si affronteranno problematiche legate alla meccanica della frattura ed alla caratterizzazione delle ceramiche e dei materiali compositi, impiegando in maniera duale l’approccio sperimentale e tecniche numeriche. In particolare si svilupperà una tecnica speciale per la simulazione delle proprietà ceramiche capace di descrivere i complicati processi di nucleazione del danno e di propagazione della frattura. I risultati numerici verranno verificati mediante varie tecniche a raggi x in-situ ed in laboratorio ricreando ambienti realistici. Modellazione di componenti meccaniche in presenza di difetti. Strutture ceramiche con difetti e interfacce imperfette, con enfasi sull’interazione fra incrinature e microstruttura, verranno analizzate mediante modellazione analitica e numerica. Nuove applicazioni tecnologiche per i materiali ceramici. L’obiettivo è la modellazione e progettazione di prodotti ceramici innovativi contenenti strati sottili d’interfaccia ed aventi proprietà multifunzionali. Il progetto è inoltre volto a stimolare la mobilità intersettoriale e a migliorare la condivisione delle conoscenze tra i partner del consorzio, in particolare mediante l’assunzione di ricercatori esperti, il distaccamento di personale dall’accademia al settore industriale e viceversa e l’organizzazione di conferenze internazionali, workshop e seminari. Il consorzio responsabile del progetto di ricerca, oltre all’Università di Trento, vede la partecipazione delle università britanniche di Liverpool e Aberystwyth e di due industrie. I partner industriali sono la EnginSoft, che si occupa degli aspetti computazionali della modellazione di componenti ceramiche, e la Sacmi, gruppo internazionale e leader mondiale nel settore delle macchine per la produzione di ceramici.
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Davide Bigoni e Luca Deseri Università di Trento Gruppo di ricerca in Meccanica dei Solidi e delle Strutture http://ssmg.unitn.it/ Sito del Progetto INTERCER2 http://intercer2.unitn.it/
EnginSoft ed il progetto INTERCER2 EnginSoft contribuirà al progetto collaborando con le Università e con Sacmi per lo sviluppo e l’implementazione di modelli di simulazione del processo di formatura del materiale ceramico. A partire da modelli esistenti in letteratura, che faranno da banco di prova, fino ad arrivare all’implementazione delle equazioni costitutive innovative per la descrizione delle proprietà meccaniche della ceramica che andranno declinate all’interno dello strumento FEM in relazione ai tipi di analisi richieste. Non solo, EnginSoft potrà contribuire anche alla caratterizzazione degli stessi materiali sulla base di dati sperimentali e utilizzando ove necessario tecniche DOE (Design of Experiment) per la definizione di un preciso piano di esperimenti siano essi fisici o virtuali atti a comprendere al meglio la sensibilità dei più significativi parametri di uscita rispetto a quelli di ingresso Una volta disponibili modelli rappresentativi del fenomeno sarà possibile anche implementare metodologie utilizzabili al livello industriale, ed atte alla ottimizzazione del processo di produzione delle ceramiche o parti di esso, processo che ha come fine ultimo lo sviluppo di prodotti ceramici innovativi. Il progetto pur operante sul piano della ricerca e difatto rilasciando indicazioni ingegneristiche di contenuto innovativo è già noto nelle problematiche ed in metodologia per effetto di recenti attività svolte dal team di EnginSoft Il contenuto delle attività di analisi è la realizzazione di una procedura numerica tale da consentire la determinazione della forma dello stampo di un semplice componente ceramico per ottenere una precisa geometria della ceramica a valle del processo produttivo di essicazione e cottura. Tuttavia lo studio è da intendersi come preliminare, in quanto le leggi che descrivono il comportamento del materiale in queste due fasi, sono ricavate da modelli semi-empirici noti in letteratura. Tali leggi potranno essere sostituite da modelli più accurati in eventuali fasi successive di analisi. In estrema sintesi lo studio si sviluppa sulla capacità di riprodurre una geometria in formato 3d in seguito ad una serie di analisi pilotate autonomamente ed automaticamente dal software e a partire da una popolazione di forma iniziali fino ad arrivare alla forma ottima in grado cioè di ridurre al minimo la differenza tra la forma finale ottenuta numericamente e quella obiettivo desiderio del marketing. Per ulteriori informazioni: Francesco Franchini, EnginSoft [email protected]
Research and Technology Transfer
54 - Newsletter EnginSoft Year 9 n°4
Corsi di Addestramento Software 2013 L'attività di formazione rappresenta da sempre uno dei principali obiettivi di EnginSoft. Per ciascuno dei possibili livelli cui la richiesta di formazione può porsi (quella del progettista, dello specialista o del responsabile di progettazione), EnginSoft mette a disposizione la propria esperienza per accelerare i tempi del completo apprendimento degli strumenti necessari con una gamma completa di corsi differenziati sia per livello (di base o specialistico), che per profilo professionale dei destinatari (progettisti, neofiti od analisti esperti). La finalità è sempre di tipo pratico: condurre rapidamente all'utilizzo corretto del codice, sviluppando nell'utente la capacità di gestire analisi complesse attraverso l'uso consapevole del codice di calcolo. Per questo motivo ogni corso è diviso in sessioni dedicate alla presentazione degli argomenti teorici alternate a sessioni 'hands on', in cui i partecipanti sono invitati ad utilizzare attivamente il codice di calcolo eseguendo applicazioni guidate od abbozzando, con i suggerimenti del trainer, soluzioni per i problemi di proprio interesse e discutendone impostazioni e risultati. Anche per il 2013 EnginSoft propone una serie completa di corsi che coprono le necessità di formazione all'uso dei diversi software commercializzati. Le novità proposte, confermano che l’idea che EnginSoft ha della formazione non è una realtà statica che si ripropone uguale a se stessa di anno in anno, ma è un divenire, guidato dall'esperienza accumulata negli anni, dall'evoluzione del software e dalle esigenze delle società che si affidano a noi per la formazione del proprio personale. In tale contesto EnginSoft organizza e sviluppa anche attività didattiche attraverso un programma formativo personalizzato, soluzioni di progettati in relazione alle necessità e alle specifiche esigenze aziendali del committente.
Training
In particolare, l’offerta dei corsi ANSYS viene ridefinita ogni anno per adeguarsi, sia all’evoluzione del software ed alle caratteristiche dell’ultima versione disponibile, che all’introduzione di nuovi moduli e solutori. In tale senso si segnala: • in campo fluidodinamico-strutturale l'introduzione, accanto ai corsi tradizionalmente erogati, del corso ANSYS CFX - MECHANICAL: Corso Interazione FluidoStruttura. • in campo fluidodinamico l'introduzione del corso ANSYS CFD: Corso Avanzato di Aeroacustica. Sono stati inoltre rivisti ed aggiornati i corsi relativi a tutti gli altri software sostenuti da EnginSoft per adeguarli allo stato attuale delle relative distribuzioni. In particolare per quanto riguarda SCILAB si evidenzia l’introduzione di un nuovo corso: • SCILAB-03-IT: Introduzione a Xcos e Modelica. Dal punto di vista organizzativo nel 2013 tutte le sei sedi EnginSoft saranno impegnate nella formazione, dando la possibilità agli utenti di scegliere la location a loro più conveniente in termini di vicinanza geografica alla propria società. Tutto questo a riprova dell'impegno nella formazione che, per EnginSoft, è e rimane un punto fondamentale della politica aziendale, un impegno costante verso l'eccellenza, un servizio per fare crescere i suoi clienti e, se lo desiderano, crescere con loro.
www.enginsoft.it/formazione Segreteria organizzativa: [email protected]
GPU-POWERED G PU-POWERED SIMULATION SIMUL ATION M ORE DESIGN DESIGN V ARIATIONS MORE VARIATIONS IN L ESS TIME TIME LESS
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To learn more visit www.nvidia.com/maximus and http://www.hp.com/eu/workstations
© 2012 NVIDIA Corporation. All rights reserved. NVIDIA, the NVIDIA logo, NVIDIA Quadro, Tesla, and CUDA are trademarks and/ or registered trademarks of NVIDIA Corporation. All company and product names are trademarks or registered trademarks of the respective owners with which they are associated.
56 - Newsletter EnginSoft Year 9 n°4
International CAE Conference: like never before! More than 700 people from all over Europe attended the 28th edition of the International CAE Conference. Special guest Professor Parviz Moin, from Stanford (USA), presented innovation algorithms aimed to simulate large scale CFDs models. The edition 2012 of the “International CAE Conference”, was held October 22nd and 23rd, at the Hotel Parchi del Garda in Lazise, Verona – Italy. More than 700 people coming from all over the world and representing the fields of research, academic and the companies operating in the sector attend the Italian landmark event in the world of simulation technology and CAE (Computer Aided Engineering). Dozens of international companies and institutions engaged in the event, hardware vendors (HP, IBM) and CAE solution’s providers: EnginSoft, ANSYS, EESTECO, Mentor Graphics, Lms , AVL, SCSK and many others. Special guest, during the morning section, was Professor Parviz Moin, founder and director of the Centre for Turbulence Research at Stanford University (California). An initiative created in 1987 as a research consortium
between NASA and Stanford University and is dedicated to the study of turbulent motions; it concerns many different areas of our daily lives: from aviation to wind energy, from medicine to biology. Professor Moin has pioneered the use of Large Eddy Simulation, which is a particular methodology for the simulation of turbulence and a reference point in the sector. The conference opened with a letter by Giorgio Squinzi, President of Italian Industrial Association – CONFINDUSTRIA - who, despite his absence, wanted to express his good wishes. Squinzi highlighted the need on the part of companies 'to roll up their sleeves and tackle contingencies, without losing sight of the competitive environment in the medium term,' stressing that 'the issues addressed in the CAE Conference are undoubtedly exceptional competitive levers for the development of better products and reduced operational costs and times'.
Fig. 1 - Prof. Parviz Moin, University of Stanford, special guest of the 2012 CAE Conference
Events
Professor Moin, in his speech, emphasized the role played by simulation in terms of business and investment as well as in occupation. 'Simulation is important because it improves efficiency for companies and decreases costs he explained. Virtual testing today is used not only to validate laboratory experiments but mainly to make new discoveries, in addition, of course, to the work of designing new products. Simulations are more accurate; in particular the carrying out of the design phase has improved 20 thousand times since the origins. “Where is simulation used? As Moin explains, it
Newsletter EnginSoft Year 9 n°4 -
Fig. 2 - The Plenary Session
is an advanced technology that touches all sectors: from the design of aircraft turbines to the analysis of pollution, passing through automotive cooling systems. 'Virtual simulation can become an opportunity for employment for young people: 'Industry is adopting simulation in the process of design and production, so there are great opportunities for work - concluded Professor Moin. But it is essential to focus on a type of education that has a solid foundation in calculus, physics, and computer science'. Among the leading companies present at the event, is EnginSoft, a world leader in innovation consulting, testing and virtual CAE, as well as being a sponsor of the conference. Stefano Odorizzi, President and Founder of EnginSoft, highlighted, in his speech, that simulation has grown over the years and he especially emphasized the large number of areas where it can be applied.'Through numerical simulation it is possible to reproduce the behaviour of a particular subject in a potentially infinite number of diverse situations. From mechanics to fluid dynamics, from acoustics to the biomedical sector, simulation allows great strides forward, as it accurately reproduces reality. We have learned that networking is the key to promoting innovation, because each sector has something to offer in terms of know-how. By joining forces we can get better results'. Simulation has positive repercussions in the biomedical field, as testified by Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Remuzzi presented the research project for 'validation of computational models for surgical planning of vascular access in
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haemodialysis patients'. Currently there are about 2 million people worldwide suffering from end-stage renal disease, a condition that in most cases requires haemodialysis. As explained by Remuzzi, currently the leading cause of morbidity and hospitalization in haemodialysis patients consists of the short and long-term dysfunction in the vascular access used to connect the patient's bloodstream to the artificial kidney. 'Through this project - said Eng. Remuzzi – computational tools have been developed with the specific aim of preventing complications during surgery'. The next step will be to validate this study on the clinical front, in order to be able to understand the effectiveness, functionality and impact of this new tool that could pave the way for other simulation applications in the biomedical field. For more information: [email protected] www.caeconference.com
Fig. 3 - Attendees at the Technical Sessions
Fig. 4 - Attendees at the Exhibition Area
Events
58 - Newsletter EnginSoft Year 9 n°4
CAE Poster Award: A reward to the genius of young researchers As part of the CAE Conference, a prize has been awarded to the top six innovative ideas in the field of simulation. Amongst the winners: The University of Padua, the Mario Negri Institute and the Polytechnic of Milan. The CAE Poster Award is an award for the genius, the commitment and the resourcefulness of young people, researchers and businesses. Among this year's winning posters are: an innovative motorcycle helmet, a project that simulates the restructuring of the Arena of Verona, a method for the treatment of heart disease, new solutions in the automotive field. This award demonstrates that simulation can be a real opportunity for young people, in their exchange of ideas with companies and institutions, to reach new frontiers in occupation and employment. The Poster Award is a project promoted and sponsored by EnginSoft, a world leader in innovation consulting, with the aim of promoting and spreading the culture of simulation and of rewarding the quality of new developments by young researchers. Six of them have been rewarded for their innovative ideas in the use of virtual simulation technology. The competition was divided into two categories: Industry (for companies) and Academy (for universities) and saw the participation of more than 50 students and businesses from all over Italy and Europe. An initial selection of the 10 best posters in each category was made by a Scientific Committee, who later announced the three winners for the Industry and three students for the Academy section, who won a Tablet PC each. The event, hosted by Luca Viscardi, of Radio NumerOne, was attended by Stefano Odorizzi, president and founder of
Events
EnginSoft, and Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Odorizzi said that he was pleased with the competition: 'The Poster Awards were a success. Many projects were submitted, much beyond our expectations. Through this undertaking we wanted to create an opportunity for interaction between the business world and the universities.' Over 50 projects were presented, 31 of which reached the final stage. They are mostly posters created by young students from Italian universities, particularly from those of Padua, Salento, Basilicata and Ferrara, from the Milan and Turin Polytechnics, from the Universities of Bologna, Cassino and Pisa. One of the projects comes from the Mario Negri Institute, while, amongst the companies, we note Mox-Off, Pierburg Pump Technology and LyondellBasell. Eng. Remuzzi, representing the Mario Negri Institute, stressed the important role that virtual simulation can have in the biomedical sector, 'Biomedicine needs these new technologies to test new and different techniques, in order to achieve important results'. As for the students, the winners were: • Davide Bertini, from the University of Padua; Mr Bertini submitted a poster on the simulation of renovation of complex historical buildings, such as the Arena of Verona;
Newsletter EnginSoft Year 9 n°4 -
59
• Matteo Longoni of Mox-off; Mr Longoni implemented a project to simulate the comfort of a motorcycle helmet while aiming at reducing time and costs associated with the design phase; • Marco Stevanella, from Polytechnic of Milan; Mr Stevanella presented a study to detect and quantify aortic malformations, which affect about 2 percent of the European population. Amongst the companies and the research community, the winners were: • Massimo Nutini, who submitted a poster on the characterization of plastic reinforced with glass fibre, widely used in most industrial productions. Nutini works for LyondellBasell, the third largest independent chemical company in the world; • Lorenzo Botti, from the Mario Negri Institute, presented a study, on an open source software platform, concerning a system that simulates blood circulation; • Giorgio Peroni of Pierburg Pump Technology presented a poster on the vacuum pump, for automotive applications. For more information: EnginSoft Marketing Department [email protected]
EnginSoft sostiene le attività di Ricerca dell'Istituto Mario Negri di Milano Venerdì 30 Novembre Stefano Odorizzi, ha visitato la sede di Milano - Bicocca dell’Istituto Mario Negri per rinnovare la collaborazione tra EnginSoft e la Fondazione iniziata in occasione dell’International CAE Conference 2012. Silvio Garattini, fondatore e Direttore dell’istituto di ricerche farmacologiche, ha accompagnato il CEO di EnginSoft in una vista ai laboratori e agli strumenti in dotazione alle centinai di ricercatori che si adoperano quotidianamente nella comprensione degli intimi meccanismi di funzionamento degli organismi viventi ed individuare le ragioni per cui insorgono le varie malattie in seguito all'introduzione di sostanze estranee. Nel corso dell’incontro Odorizzi ha consegnato al Professor Garattini un contributo di destinato ad alimentare le attività della Fondazione. “Ringrazio EnginSoft, e la sensibilità dell’ingegner Odorizzi, per l’attenzione dimostrata al lavoro svolto dell’Istituto – ha dichiarato Silvio Garattini -. Il sostegno profuso da Aziende e privati cittadini è un pilastro fondamentale e strategico sul qual poggia il Mario Negri. Questa generosità consente a tutti noi di combattere, da oltre 50 anni, la quotidiana battaglia contro le malattie dell’uomo”. “EnginSoft sostiene da sempre la Ricerca e le iniziative atte a valorizzare il capitale intellettuale dei giovani ricercatori e riteniamo questa collaborazione con il Mario Negri un ottimo modo per farlo – afferma Stefano Odorizzi -. Ringraziamo il
Professor Silvio Garattini per averci dato questa preziosa opportunità e ci auguriamo che ci siano altri importanti progetti per unire le nostre forze”. L'Istituto di Ricerche Farmacologiche Mario Negri è un'organizzazione scientifica che opera nel campo della ricerca biomedica. È stato costituito giuridicamente nel 1961 e ha iniziato le attività nella sede di Milano il 1° febbraio 1963. L’impegno della fondazione guidata da Silvio Garattini si articola, oltre che sulla Ricerca Farmacologica, anche nell’Informazione e Formazione. Infatti l'Istituto svolge anche attività di insegnamento per la formazione professionale di tecnici di laboratorio e ricercatori laureati e contribuisce, con molteplici iniziative, alla diffusione della cultura scientifica in campo biomedico: sia in senso generale che a specifico sostegno della pratica sanitaria per un uso più razionale dei farmaci. Tutti possono contribuire a sostengo delle attività dell’Istituto Mario Negri. I contributi che Enti e Privati Cittadini offrono all'Istituto di Ricerche Farmacologiche Mario Negri sotto forma di liberalità, donazioni e lasciti ereditari sono devoluti a incrementare i programmi di ricerca per lo studio delle più gravi malattie che affliggono l'uomo e a istituire borse di studio per i giovani ricercatori cui saranno affidate le ricerche future. Dettagli sulle attività di Ricerca, e come sostenerle con un contributo tangibile, possono essere consultate sul sito web dell’Istituto: www.marionegri.it
Events
CAE Poster Award 2012: Winners
Dipartimento di Costruzioni e Trasporti
Introduction The simultaneous need to preserve historic heritage and to appreciate its seismic vulnerability requires the development of techniques and methods used to properly establish the structural behaviour of historical monuments .
Method
resulting from non-destructive diagnostic tests, carried out on the masonry structures of the building, which allow to detect the real mechanical behaviour without loss of their functionality and efficiency.
Steps of the work The work has required the completion of the following basic steps:
x creation of a Finite Element Model complete in terms of structural geometry, loads, constraints and material properties;
x recovery of data from experimental studies previously carried out in significant positions of the monument;
x calibration of the model on the basis of the results of tests in situ.
Assumptions The starting hypothesis on which is based the development of the entire modeling is the use of materials with a linear elastic constitutive law . This assumption is generally recommended especially for qualitative analysis designed to asses the structural behaviour of a complex building.
Simulation and experimental validation The Finite Element Model of the whole building was refined and calibrated on the basis of data from experimental investigations carried out on the so-called 'Ala' ,
t vibration modes, it was obtained a significant correspondence between simulation
what is left of external ring after destructive past earthquakes.
and experimental results which has allowed to judge the correctness of the dynamic
In 1996 were realized some tests to determine its structural behaviour in relation to
behaviour of the Finite Element Model.
dynamic stresses: the acquisition of the signals was made with four accelerometers placed in pre-selected points of the structure. The Frequency Response Function obtained represents the deformability of each point of the structure to vary the excitation frequency. Modal shapes resulting from dynamic simulation applied to the Finite Element Model
[m]
Mode 01
Mode 02
Mode 03
Frequency 1,68 Hz
Frequency 2,42 Hz
Frequency 4,91 Hz
Mode 04
Mode 05
Mode 06
Frequency 5,89 Hz
Frequency 6,20 Hz
Frequency 7,18 Hz
P03 P01
Experimental Frequency Response Function for control points P01 and P03
P04 P02
1.4E-04 1.2E-04 1.0E-04 8.0E-05 6.0E-05 4.0E-05 2.0E-05 0.0E+00 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
[Hz]
Findings The modeling has been conducted assuming a linear elastic behaviour of all materials. This approximation has proved to be very useful to develop a model sufficiently accurate, avoiding the complications introduced by the use of non-linear diagrams. The validity of elastic modeling is demonstrated by the fact that the starting model, without corrections for adaptation to experimental values, has directly provided results very close to reality.
Future developments The study could be further developed taking into consideration the real constitutive laws of materials and the localized phenomena of deterioration which may affect the structural behaviour of the building.
CAE Poster Award 2012: Winners A multiphysic approach to improve helmets comfort and reduce time and costs in design process Longoni Matteo1, Formaggia Luca2, Ferrandi Paolo1 1
Moxoff Srl, Via D’Ovidio 3, 20131 Milano, Italy 2 MOX - Modeling and Scientific Computing Dipartimento di Matematica “F. Brioschi”, Politecnico di Milano, Italy Motivation
Goal
Improve helmet comfort in every-day conditions Key issue: pleasure of driving and safety
Develop a support design tool for engineers Simulate helmet performances efficiently
Technology
Starting point: very latest research works Handling of real and complex CAD geometries Model coupling: aerodynamics 3D, thermofluid 2D and vibroacustics 3D Multiphase (water/vapour) flows in porous media (comfort tissue/human hair) Human head sweating model for heat generation Advanced numerical methods Improvement and development of robust simulation codes Mathematical model
Vibroacoustic model - WIP!
ThermoFluid dynamic problem Navier–Stokes coupled with Darcy–Forchheimer: Penalized NS 0003 0002 ρCF μ (ρ(u · ∇)u − μΔu) χΩf + ∇p + u + √ |u|u χΩp = 0 k k ∂T + Cf u · ∇T = ∇ · (λp ∇T ) − le s(h, w , T ) Temperature T : ∂t ∂h Humidity h: + u · ∇h = Dh Δh + s(h, T , w ) ∂t ∂w Sweat content w : = ∇ · (Dw ∇w ) − s(h, T , w ) ∂t 0004 Mv Evaporation rate s: s(h, T , w ) = E (psat (T ) − pv (h, T )) χw + 2πRT
Ωf ,p ,w = fluid , porous, wet domain ρ = air density u = flow velocity t = time μ = dynamic viscosity p = pressure k = permeability Dh = water diffusivity χ = indicator function Cf , λp , le = thermodynamics Mv , R, psat , pv = psychrometrics CF , Dw , E = coefficients
Elastodynamics equations: ⎧ ρ∂tt u − ∇ · σ(u) = f, in Ω × [0, T ] ⎪ ⎪ ⎪ ⎪ on ΓD × [0, T ] ⎪ u = 0, ⎪ ⎨ σ(u) · n = t, on ΓN × [0, T ] on ΓNR × [0, T ] ⎪ non-reflecting b.c., ⎪ ⎪ ⎪ in Ω × {0} ⎪ ∂ t u = u1 , ⎪ ⎩ in Ω × {0} u = u0 ,
u = displacement t = time n = unit normal σ = stress tensor u0,1 = initial conditions f = external force Ω = 3D domain Γ = boundaries
Discontinuous Galerkin formulation Space–Time formulation Multi-domain formulation 3D hexa mesh
Multiphysic approach
0002
0002
Results
Accurate and efficient simulations of the physics involved Evaluation tool for engineers to explore different design solutions Time and costs of the overall design process drastically improved Optimized process satisfying comfort requirements for a successful product.
References P.F.Antonietti et al., “Non-conforming high order approximations of the elastodynamics equation”, CMAME, 2012. C.Canuto and F.Cimolin, “A sweating model for the internal ventilation of a motorcycle helmet”, Computers & Fluids, 2011.
M.Longoni, L.Formaggia, P.Ferrandi Moxoff, MOX
09/2012
A multiphysic approach to improve helmets comfort
CAE Poster Award 2012: Winners ZZZ0011ELRPHFK0011SROLPL0011LW0003
Healthy and BAV-affected aortic root dynamics: Fluid-Structure Interaction simulations from MRI-based 3D models M. Stevanella1, F. Sturla1,2, C.A. Conti1, E. Votta1, A. Della Corte3, A. Redaelli1 1 Department of Bioengineering, Politecnico di Milano, Milan, Italy Division of Cardiovascular Surgery, Università degli Studi di Verona, Verona, Italy Department of Cardiothoracic and Respiratory Sciences, Seconda Università di Napoli, Naples, Italy 2
3
Results and Discussion
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3
Flash Virtual Simulation creates more and more interest in diverse industrial fields and among the young; it is a driving force for innovation, for employment and creates opportunities for companies.
It is in this spirit that we are approaching the New Year at EnginSoft. We invite our readers to enjoy the articles in this Newsletter and to contact us with feedback and ideas for collaboration.
With the CAE Poster Award, EnginSoft fosters and promotes collaborations between industry and universities. At the International CAE Conference 2012, the Award was presented for the first time to six outstanding Young Researchers and businesses for their highly innovative work in the field of simulation. Many of our guests with whom I spoke at the Conference shared the enthusiasm for innovative research and to create new business, to realize visions, to make the most out of the enormous resources we have available in our network.
This issue presents contributions on the use of modeFRONTIER for the optimization of a boomerang shape, the analysis work performed for a frequency-reconfigurable microstrip antenna and the Particle Finite Element Method, PFEM. The latter is an effective numerical technique for multidisciplinary engineering problems which involve fluidsoil-structure interaction. Alenia Aermacchi, Politecnico di Torino and the Università del Salento inform us about ECS System Simulation for architecture and performance optimization. Further case studies cover the development work of Lovato Electric, the Feat Group, the Department of Information Engineering of University of Pisa as well as the use of the Grapheur technology for material selection.
While the year turns to an end, we are building on these foundations, on the opportunities and new activities we have created together with our customers and partners. Success is possible – together.
We introduce the RuBeeCOMP, the INTERCER2 and the “MUSIC” (which stands for: Multi-layer control & cognitive System to drive metal and plastic production line for Injected Components) Research Projects. Our Software Updates feature the latest ANSYS Workbench 14.5 release and SIMPACK, a multi-body simulation tool. We report from the TechNet Alliance Fall Meeting in Germany, the Round Table Meeting of companies from Venetia and offer a comprehensive review of the International CAE Conference to which EnginSoft had the great pleasure to welcome more than 700 attendees. We encourage our readers to download the Conference Proceedings and to look at the inspiring work of the awarded young researchers, the six Posters we also highlight in this Newsletter. Please stay tuned to the EnginSoft Training Program and Event Calendar. We hope to welcome many of you to our CAE courses and events in 2013 and beyond. EnginSoft and the Editorial Team wish you and your families a very happy, healthy and a prosperous New Year!
Stefano Odorizzi Editor in chief
Ing. Stefano Odorizzi EnginSoft CEO and President
Flash
4 - Newsletter EnginSoft Year 9 n°4
Sommario - Contents
CASE STUDIES
6 10 14 16 24 26 30 33
Optimization of a Boomerang shape using modeFRONTIER The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Frequency-Reconfigurable Microstrip Antenna for Software Defined Radio ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot Grapheur for Material Selection Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura
RESEARCH & TECHNOLOGY TRANSFER
41
Multidisciplinary Optimization for an IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform
44
Meeting conclusivo del progetto 'RuBeeCOMP'
SOFTWARE UPDATES
45 47
Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 Simulating Gear Pairs within SIMPACK
RESEARCH & TECHNOLOGY TRANSFER
50 52 53
EnginSoft coordinates the new “MUSIC” European Project Modellazione e Progettazione Ottimale di Strutture Ceramiche EnginSoft ed il progetto INTERCER2
TRAINING
54
Corsi di Addestramento Software 2013
EVENTS
56 58 59 66 68
International CAE Conference: like never before!
70 71
Trainer europei di ANSYS alla scuola EnginSoft
CAE Poster Award. A reward to the genius of young researchers EnginSoft sostiene le attività di Ricerca dell’Istituto Mario Negri di Milano Le reti d’impresa? Serve un cambio di mentalità CAE Conference 2012 welcomed Sponsors from Japan. Post-conference interviews Event Calendar
Contents
Newsletter EnginSoft Year 9 n°4 -
5
Newsletter EnginSoft Year 9 n°4 - Winter 2012
PAGE 16 ECS SYSTEM SIMULATION OF AN ALENIA AIRCRAFT
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PAGE 24 HOW GEOMETRICAL DIMENSIONING & TOLERANCING INFLUENCES THE PERFORMANCES OF AN ELECTROMECHANICAL CONTACTOR
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PAGE 56 INTERNATIONAL CAE CONFERENCE 2012: MORE THAN 700 PARTICIPANTS The EnginSoft Newsletter editions contain references to the following products which are trademarks or registered trademarks of their respective owners: ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. [ICEM CFD is a trademark used by ANSYS, Inc. under license]. (www.ansys.com) modeFRONTIER is a trademark of ESTECO srl (www.esteco.com)
Cascade Technologies www.cascadetechnologies.com Reactive Search www.reactive-search.com SimNumerica www.simnumerica.it M3E Mathematical Methods and Models for Engineering www.m3eweb.it
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Flowmaster is a registered trademark of Menthor Graphics in the USA (www.flowmaster.com) MAGMASOFT is a trademark of MAGMA GmbH. (www.magmasoft.de) Forge and Coldform are trademarks of Transvalor S.A. (www.transvalor.com) LS-DYNA is a trademark of Livermore Software Technology Corporation (www.lstc.com) Grapheur is a product of Reactive Search SrL, a partner of EnginSoft (www.grapheur.com) Simpack is a product of SIMPACK AG (www.simpack.com) For more information, please contact the Editorial Team
RESPONSIBLE DIRECTOR Stefano Odorizzi - [email protected] PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA
Contents
Autorizzazione del Tribunale di Trento n° 1353 RS di data 2/4/2008
PAGE 41 MULTIDISCIPLINARY OPTIMIZATION FOR AN IEE 1902.1 “RUBEE” TAG
ESTECO www.esteco.com CONSORZIO TCN www.consorziotcn.it • www.improve.it
6 - Newsletter EnginSoft Year 9 n°4
Optimization of a Boomerang shape using modeFRONTIER A boomerang is a flying object apparently simple but particularly challenging for the complex physics modeling, since it should indeed involve: • six degrees of freedom body dynamics; • aerodynamics of rotational blades; • personal capabilities of the thrower; In this paper we show how the design optimization software modeFRONTIER, developed by ESTECO, can be employed for a non-standard problem consisting in the numerical simulation of the boomerang flight and the final optimization of its shape. The boomerang trajectory is obtained by means of a dynamic model integrated to a CFD analysis able to compute aerodynamic coefficients. To steer the complete optimization process modeFRONTIER is coupled to Catia v5 for the boomerang shape modification, to MATLAB for the dynamic simulation, and to Star-CCM+ for aerodynamic analysis. Moreover, dedicated RSM (Response Surfaces Methods) available in modeFRONTIER are used to extrapolate the aerodynamic coefficients as a function of the boomerang angle of incidence and velocity, as required by the dynamic model, allowing a reduced number of CFD analyses for each geometric configuration. Different design simulations are therefore automatically executed by modeFRONTIER, following a dedicated optimization strategy until the optimal geometry of the boomerang is found accordingly to the specified requirements, such as minimum energy for the launch and desired accuracy in returning. 1. Equations of the boomerang motion Considering that a boomerang spins fast, it is possible to write the so-calleds moothed boomerang equations in which the different quantities (velocities, angles, forces) are timeaveraged over a boomerang rotation:
where: Iz is the maximum boomerang principal moment of inertia; V is the velocity magnitude of the boomerang center
Case Histories
of mass; m the boomerang mass; ψ is the angle of incidence of the boomerang; ϑ, φ, ψ are the Euler angles of a xyz reference system partially fixed on the boomerang (such that the boomerang center of mass is always placed in the xyz origin, the z axis is always directed as the maximum boomerang moment of inertia axis, namely normal to the section plane shown in Fig.3, and the projection of the boomerang center of mass velocity on the xy planes is directed as the –x axis); ωz the boomerang angular velocity around the z axis; Tx, Ty, Tz, Fx, Fy, Fz, are torque and force components in the xyz reference system, basically due to the interaction between the boomerang and the air and the gravity force. The gravity force can be expressed in the xyz reference system as:
The absolute position of the boomerang center of mass can be found as function of the previous parameters by:
The equations of motion can be integrated numerically (high order Runge-Kutta method) once the initial conditions are provided and the forces and torques are available at any time step. A candidate boomerang trajectory can therefore be simulated through the flowing steps: i) for a certain number of Ψ and U pairs (where U=V/ωza), with a distance between the boomerang center of mass and the farthest boomerang point from the center of mass) the corresponding not-dimensional values of F and T are computed by CFD simulations: a dimensional analysis can prove indeed that F and T depend only on Ψ and U for a given boomerang geometry and for a Reynolds number range typical of boomerang flights; ii) response surfaces for F(Ψ,U) and T(Ψ,U) are built; iii) equations of motion are integrated starting from given initial conditions and using the response surfaces computed previously to express forces and torques at any position and time step. The trajectory of the boomerang is affected by the initial conditions, namely by the way the boomerang is launched.
Newsletter EnginSoft Year 9 n°4 -
7
Four launching parameters are considered (they will be automatically tuned for each candidate boomerang by the optimization methodology described in section 4): • V: initial boomerang translational velocity; • Spin: initial boomerang spin; • Aim: angle between the initial boomerang translational velocity and the horizontal plane; • Tilt: angle between the initial boomerang rotational plane and the vertical axis (0° tilt corresponds to a vertical boomerang plane of rotation). 2. Boomerang Parameterization The boomerang geometry chosen for the optimization will be the classical two arms “V” and “Ω” shape type. The most important parameters that affect the boomerang behavior are linked to the blades profile, the angle between the two arms and the dihedral of the arms. A total number of 9 input parameters has been defined. A. Blade profiles Changing the profile by playing with the angle of attack and cutting on the top of the leading and trailing edge can change a lot the lift provided by the arm. The lift in particular affects the turn capability of the Fig. 1 - Effect on blade profile of Bezier boomerang (precession control points effect). The arc blades are in general designed with a positive angle of attack; this helps the boomerang plane to lay down and to float in air. For the parametric boomerang geometry a flat bottom airfoil has been chosen. The blade profiles are built by a Bezier parametric curve, with 4 control points. The profile shape is modified by the changing vertical and horizontal position of the Bezier control points. In this way it is possible to change the angle of attack and the thickness of the blades (see Fig.1). The profiles of the leading and of the trailing arm are controlled by the same parameters, in order to reduce their total number. In particular the vertical position of the trailing arm is set as a fraction of the vertical position of the leading arm. B. Dihedral angle Boomerang arms usually have a positive dihedral angle of about 10°-15°; the dihedral affects both the lift and the lay down velocity of the rotation plane, keeping practically unchanged the mass of the boomerang. The boomerang parametric model is provided with the two parameters α and d that allow to change the dihedral by removing a small amount of material from the boomerang arms tips (Fig.2). The α parameter is basically the stabilizer’s angle of attack.
Fig. 2 - Leading and trailing edges; dihedral angle.
C. Angle between arms This angle usually ranges between 70° and 140°. In fact, this parameter has an important effect on the boomerang stability. The length of the arms is fixed to keep a constant overall size of the boomerang. 3. Aerodynamic forces computation details by CFD The CFD software employed is Star-CCM+. The approach we considered consists in using two reference systems - one external and inertial, the other fixed with respect to the boomerang and having its origin placed in the boomerang center of mass. Also, two domains and two grids are used: the first is spherical, having its origin placed in the boomerang center of mass and associated to the boomerang reference system; the second corresponds to an external parallelepiped shape associated to the external reference system. The internal spherical domain is provided with a rotation velocity around an axis normal to the boomerang plane and passing through the boomerang center of mass. The information exchange between the two domains is provided by an interface boundary that allows to interpolate the field values. In Star-CCM+, a polyhedral mesh with prisms layers at the boomerang walls is defined within the sphere around the boomerang and an hexahedral mesh is defined in the rest of the domain (Fig.3). The two-equations RANS SST (Shear Stress Transport) turbulent model, with wall functions, is chosen and a segregated solver with constant density is employed. A mesh size of about 2.5 millions of cells has been defined, this being a good tradeoff between Fig. 3 - Particular of a mesh section
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8 - Newsletter EnginSoft Year 9 n°4
Fig. 4 - CFD results on different revolution frames
accuracy and computational efforts. Fig.4 shows the pressure field on a boomerang surface in different time steps during a rotation. It is possible to notice that the pressure force on each arm changes a lot during the rotation according to the relative position of the blades with respect to the translational velocity. At the end of the numeric simulation (for a given Ψ,U pair) the averaged forces and torques acting during the rotation are computed and then the corresponding F and T are available. 4. Process flow automation in modeFRONTIER The whole process aiming at evaluating and optimizing the performances of the boomerang has been completely automatized through the software modeFRONTIER. In this modular environment, the complete process flow is defined by the user, who can select among several available optimization algorithms, including Genetic and Evolutionary Algorithms, Game Strategies, Gradient-based Methodologies, Meta-Models and Robust Design Optimization.
Fig. 5 - modeFRONTIER main workflow
modeFRONTIER effectively automates the computation of the boomerang trajectory through the following steps: 1. modify the boomerang Catia model parameters; 2. obtain the updated geometry (stl file) from Catia and transfer it to Star-CCM+ execution module; 3. launch Star-CCM+ to build the computational mesh; 4. launch different Star-CCM+ simulations using the same mesh prepared as above varying U and Ψ parameters for an appropriate number of samples; for each U and Ψ pair the corresponding forces and torques F and T are obtained;
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5. use the set of simulations computed in iv) as training set to build in modeFRONTIER response surfaces to obtain F(Ψ,U) and T(Ψ,U) over the whole range of variation of Ψ,U 6. pass the response surfaces and the boomerang inertia data to a MATLAB script to compute the trajectory by integrating equations of motion using a 4th order RungeKutta method; 7. run an internal optimization for the given configuration to tune the four launching parameters (by minimizing the arrival distance); 8. the main multi-objective algorithm assesses how good the trajectory is with respect to specified objectives (total energy needed for the launch to be minimized) 9. the steps i)-viii) are repeated automatically by the algorithm until one or more optimal configurations are obtained. The modeFRONTIER workflow is shown in Fig.5. In particular, on the top we find the nodes (green subsystem) that define the range of variations of all the geometrical parameters, then the process flow (black line) starts with the interfaces to select the optimization algorithms and set their options, to continue with the CATIA direct interface that allows to automatically update the geometric model at the variation of the parameters, obtaining as results the updated Stl model, which is transferred to the following script node used to run Star-CCM+ to create the mesh for the proposed geometry. The mesh (.sim file) is then transferred to the following application node, which basically launches in batch mode another modeFRONTIER project file, running a set of CFD computations through Star-CCM+ on the same mesh varying U and Ψ parameters, as described at point iv) above. The output of the internal modeFRONTIER project is a Response Surface (RSM) or Metamodel, based on the available training set, able to extrapolate F(Ψ,U) and T(Ψ,U) over the whole range of variation of the two parameters (fig.6). The algorithm used for the RSM training is Kriging and the model is automatically exported as a C-script, which can be read by MATLAB. The last application node in the process flow is another modeFRONTIER project node, called “launch_parameters_tuning”. This node actually runs another optimization project in batch mode, using as input variables the four launch parameters described in section 1. The boomerang shape is fixed and the objective is defined by the minimization of the distance from the arrival position and the launching position. For this purpose, a fast monoobjective algorithm is used (Simplex) and the project just executes a MATLAB script through the corresponding direct interface for each set of launching parameters; basically the script drives a Runge-Kutta integration to compute the
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Fig. 6 - Response surfaces of boomerang aerodynamic forces
boomerang trajectory (retrieving the needed F(Ψ,U) and T(Ψ,U) values for each integration time step directly from the Response surface available for each boomerang geometry). The final outcome of the modeFRONTIER Batch node in the main process flow for each boomerang geometry is therefore its tuned trajectory, whose performances are to be optimized in the external loop. For this purpose, from this node the following outputs are extracted: • Range: this is the maximum distance reached by the boomerang during its flight; it has just been considered as a constraint in the optimization, to penalize configurations of too small range;; • Accuracy: this is the difference between the position from which the boomerang is launched and the position where the boomerang returns (optimized by the internal loop as described above for each boomerang candidate solution) • Energy: this is the energy (translational plus rotational) necessary to launch the boomerang, that is a quantity to be minimized (to reduce the effort for the thrower). 5. Optimization Strategy and Optimization Results Several tests were performed in order to find the proper number of simulations required to create enough accurate response surfaces. It has been found that a matrix of 12 points guarantees an error of approximation lower than 5% and this was the size of the training set finally selected. This means that each boomerang trajectory computation needs 12 CFD simulations. For this reason a classical multi-objective optimization algorithm that may require hundreds of designs evaluations is not practically feasible, therefore a different strategy, based on the Game Theory (Hierarchical Games), has been chosen. As indicated in the previous chapter, two different objectives (returning accuracy and launch global energy) have to be considered. Actually, any candidate solution is first optimized by the internal workflow in order to tune the launching parameters (follower player); then, the identified optimal solution is evaluated by the external optimization workflow which handles the energy objective minimization by changing properly the geometrical parameters (leader player). Note that for both the internal and external optimizer the same modeFRONTIER algorithm, Simplex, has
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been used due to its efficiency to solve single-objective problems in few iterations. Fig.7 reports the global results of the optimization process, in the space of the objectives and constraints considered. In particular the abscissa reports the launch energy (Joule), the ordinate indicates the range (meters), and the color of the bubbles reports the returning accuracy for each design (distance in meters). At the end of the process, one of the optimal boomerang configuration has been chosen and its geometry and trajectory are also reproduced in Fig.8. The energy required to launch the boomerang is 3.5 J, the ratio of rotational with total energy is only 7% that corresponds to an initial spin of about 4 Hz and to an initial translational velocity equal to 15 m/s; the tilt angle is 0°, while the aim is about 20°. This set should make the boomerang launch pretty easy, with a range of 14.5 m. In conclusion, this paper has described an automatic and efficient methodology for the multi-objective optimization of a boomerang shape, resulting an interesting benchmark and proof of concept to illustrate the multi-objective and multidisciplinary capabilities of the optimization environment modeFRONTIER. Rosario Russo, Alberto Clarich - ESTECO Spa Enrico Nobile, Carlo Poloni - Università di Trieste For more information: Francesco Franchini, EnginSoft [email protected]
Fig. 7 - Optimization results
Fig. 8 - Optimal boomerang configuration and trajectory
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10 - Newsletter EnginSoft Year 9 n°4
The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Introduction The analysis of problems involving the interaction of fluids, soil/rocks and structures is relevant in many areas of engineering. Examples are common in the study of landslides and their effect on reservoirs and adjacent structures, off-shore and harbour structures under large waves, constructions hit by floods and tsunamis, soil erosion and stability of rockfill dams in overspill situations, excavation and drilling problems in civil and petroleum engineering, etc. The author and his group have developed in previous works a particular class of Lagrangian formulation for solving problems involving complex interactions between (free surface) fluids and solids. The so-called particle finite element method (PFEM, www.cimne.com/pfem), treats the mesh nodes in the fluid and solid domains as particles which can freely move and even separate from the main fluid domain representing, for instance, the effect of water drops. A mesh connects the nodes discretizing the domain where the governing equations are solved using a stabilized FEM. An advantage of the Lagrangian formulation used in PFEM is that the non-linear and non symmetric convective terms disappear from the fluid equations. The difficulty is however transferred to the problem of adequately (and efficiently) moving the mesh nodes. In the next section the key ideas of the PFEM are outlined. Next the basic equations for a general continuum using a Lagrangian description and the formulation are schematically presented. We present several examples of application of the PFEM to solve multidisciplinary FSSI problems such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the study of a landslide falling into a reservoir, the sinking of ships and the collision of ships with ice blocks.
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The basis of the particle finite element method In the PFEM both the fluid and the solid domains are modelled using an updated Lagrangian formulation. That is, all variables are assumed to be known in the current configuration at time t. The new set of variables in both domains is sought for in the next or updated configuration at time t + Δt. The finite element method (FEM) is used to solve the equations of continuum mechanics for each of the subdomains. Hence a mesh discretizing these domains must be generated in order to solve the governing equations for each subdomain in the standard FEM fashion. The quality of the numerical solution depends on the discretization chosen as in the standard FEM. Adaptive mesh refinement techniques can be used to improve the solution.
Fig. 1 - Scheme of a typical solution with PFEM. Sequence of steps for moving a “cloud” of nodes representing a domain containing a fluid and a solid part from time n (t=tn) to time n+2 (t=tn + 2Δt)
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For clarity purposes we will define the collection or cloud of nodes (C) pertaining to the analysis domain (V) containing the fluid and solid subdomains and the mesh (M) discretizing both domains. A typical solution with the PFEM involves the following steps. 1. The starting point at each time step is the cloud of points in the fluid and solid domains. For instance nC denotes the cloud at time t = tn (Figure 1). 2. Identify the boundaries for both the fluid and solid domains defining the analysis domain nV in the fluid and the solid. This is an essential step as some boundaries (such as the free surface in fluids) may be severely distorted during the solution, including separation and reentering of nodes. The Alpha Shape method is used for the boundary definition. 3. Discretize the fluid and solid domains with a finite element mesh. nM We use an effect mesh generation scheme based on the extended Delaunay tesselation. 4. Solve the coupled Lagrangian equations of motion for the overall continuum. Compute the state variables in at the next (updated) configuration for t + Δt: velocities, pressure and viscous stresses in the fluid and displacements, stresses and strains in the solid. 5. Move the mesh nodes to a new position n n+1C where n+1 denotes the time tn + Δt, in terms of the time increment size. This step is typically a consequence of the solution process of step 4. 6. Go back to step 1 and repeat the solution for the next time step to obtain n+2C (Figure 1). We emphasize that the key differences between the PFEM and the classical FEM are the remeshing technique and the identification of the domain boundary at each time step. Generation of a new mesh A key point for the success of the PFEM is the fast regeneration of a mesh at every time step on the basis of the position of the nodes in the space domain. In our work the mesh is generated using the so-called extended Delaunay tesselation (EDT). As a general rule for large 3D problems meshing consumes around 15% of the total CPU time per time step, while the solution of
Fig. 2 - Modelling of contact conditions at a solid-solid interface with the PFEM
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the equations (with typically 3 iterations per time step) and the system assembly consume approximately 70% and 15% of the CPU time per time step, respectively. These figures refer to analyses in a single processor Pentium IV PC and prove that the generation of the mesh has an acceptable cost in the PFEM. Indeed considerable speed can be gained using parallel computing techniques. Identification of boundary surfaces One of the main tasks in the PFEM is the correct definition of the boundary domain. Boundary nodes are sometimes explicitly identified. In other cases, the total set of nodes is the only information available and the algorithm must recognize the boundary nodes (Figure 2). In our work we use a Delaunay partition for recognizing boundary nodes and, hence, boundary surfaces. This is performed by using the so-called Alpha Shape method. This method also allows one to identify isolated fluid particles outside the main fluid domain. These particles are treated as part of the external boundary where the pressure is fixed to the atmospheric value. We recall that each particle is a material point characterized by the density of the solid or fluid domain to which it belongs. The mass lost when a boundary element is eliminated due to departure of a node from the analysis domain containing a fluid is regained when the node falls down and a new boundary element is created by the Alpha Shape algorithm. The boundary recognition method is useful for detecting contact conditions between the fluid domain and a boundary, as well as between different solids as detailed in the next section. Treatment of contact conditions in the PFEM Known velocities at boundaries in the PFEM are prescribed in strong form to the boundary nodes. These nodes might belong to fixed external boundaries or to moving boundaries. Contact between fluid particles and fixed boundaries is accounted for by the incompressibility condition which naturally prevents fluid nodes to penetrate into the solid boundaries. The contact between two solid interfaces is treated by introducing a layer of contact elements between the two interacting solid interfaces. This layer is automatically created during the mesh generation step by prescribing a minimum distance (hc) between two solid boundaries. If the distance exceeds the minimum value (hc) then the generated elements are treated as fluid elements. Otherwise the elements are treated as contact elements where a relationship between the tangential and normal forces and the corresponding displacement is introduced (Figure 2). This algorithm allows us to identify and model complex frictional contact conditions between two or more interacting bodies moving in water in an extremely simple manner. The algorithm can also be used effectively to model frictional contact conditions between rigid or elastic solids in structural mechanics applications. Modeling of bed erosion Prediction of bed erosion and sediment transport in open channel flows are important tasks in river and environmental
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12 - Newsletter EnginSoft Year 9 n°4 engineering. Bed erosion can lead to instabilities of the river basin slopes. It can also undermine the foundation of bridge piles thereby favouring structural failure. Modeling of bed erosion is also relevant for predicting the evolution of surface material dragged in earth dams in overspill situations. Bed erosion is one of the main causes of environmental damage in floods. In a recent work we have proposed an extension of the PFEM to model bed erosion. The erosion model is based on detaching elements belonging to the bed surface in terms of the frictional work at the surface originated by the shear stresses in the fluid. The resulting erosion model resembles Archard law typically used for modeling abrasive wear in surfaces under frictional contact conditions. Sediment deposition can be modeled by an inverse process. Hence, a suspended node adjacent to the bed surface with a velocity below a threshold value is attached to the bed surface.
Fig. 5 - Erosion of a soil mass due to sea waves and the subsequent falling into the sea of an adjacent lorry
Fig. 6 - Simulation of landslide falling on constructions using PFEM
Fig. 3 - Breaking waves on breakwater slopes containing reinforced concrete blocks
Examples Impact of sea waves on piers and breakwaters Figure 3 shows the analysis of the effect of breaking waves on two different sites of a breakwater containing reinforced concrete blocks (each one of 4x4x4 mts). The figures correspond to the study of Langosteira harbour in A Coruña, Spain using PFEM. Soil erosion problems Figure 4a shows the capacity of the PFEM for modelling soil erosion, sediment transport and material deposition in a river bed. The soil particles are first detached from the bed surface under the action of the jet stream. Then they are transported by the flow and eventually fall down due to gravity forces into the bed surface at a downstream point. Figure 4b shows the progressive erosion of the unprotected part of a breakwater slope in the Langosteira harbour in A Coruña, Spain. The non protected upper shoulder zone is progressively eroded under the sea waves. Falling of a lorry into the sea by erosion of the road slope due to sea waves Figure 5 shows a representative example of the progressive
Fig. 4 - (a) Erosion, transport and deposition of soil particles at a river bed due to an impacting jet stream (b) Erosion of an unprotected shoulder of a breakwater due to sea waves
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Fig. 7 - Lituya Bay landslide. Left: Geometry for the simulation. Right: Landslide direction and maximum wave level
erosion of a soil mass adjacent to the shore due to sea waves and the subsequent falling into the sea of a 2D object representing the section of a lorry. The object has been modeled as a rigid solid. This example and the previous ones, although still quite simple and schematic, show the possibilities of the
Fig. 8 - Lituya Bay landslide. Evolution of the landslide into the reservoir obtained with the PFEM. Maximum level of generated wave (551 mts) in the north slope
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height observed was 208 mts, while the PFEM result (not shown here) was 195 mts (6% error). Simulation of sinking of ships The PFEM can be effectively applied for simulating the sinking of ships under a variety of scenarios. Figure 9 shows images of the 2D simulation of the sinking of a cargo vessel induced by a breach in the bow region. Figure 10 displays a 3D simulation of the skinking of a simple fisherman boat induced by a hole in the side of the hull. These examples evidence the potential of PFEM for the study of the sinking of ships. Colision of boat with ice blocks Figures 11 shows an example of the application of PFEM to the study of the collision of a ship with floating ice blocks. The boat and the ice blocks have been modelled as rigid bodies in this example. Indeed, the deformation of the ship structure due to the ice-ship interaction forces can be accounted for in the analysis.
Fig. 9 - 2D simulation of the sinking of a cargo vessel due to a breach in the bow region. (a) Water streamline at different times. (b) Water velocity pattern at different times during sinking
PFEM for modeling complex FSSI problems involving soil erosion, free surface waves and rigid/deformable structures.
Conclusions The particle finite element method (PFEM) is a promising numerical technique for solving fluid-soil-structure interaction (FSSI) problems involving large motion of fluid and solid particles, surface waves, water splashing, frictional contact situations between fluid-solid and solid-solid interfaces and bed erosion, among other complex phenomena. The success of the PFEM lies in the accurate and efficient solution of the equations of an incompressible continuum using an updated Lagrangian formulation and a stabilized finite element method allowing the use of low order elements with equal order interpolation for all the variables. Other essential solution ingredients are the efficient regeneration of the finite element mesh, the identification of the boundary nodes using the Alpha-Shape technique and the simple algorithm to treat frictional contact conditions and erosion/wear at fluid-solid and solid-solid interfaces via mesh generation. The examples presented have shown the potential of the PFEM for solving a wide class of practical FSSI problems in engineering.
Modelling of landslides The PFEM is particularly suited for modelling landslide motion and its interaction with structures and the environment. Figure 6 shows a simulation using PFEM of a soil mass representing a landslide falling on four constructions modelled as rigid body solids. A case of much interest is when a landslide occurs in the vicinity of a reservoir. The fall of debris material into the reservoir typically induces large waves that can overtop the dam originating an unexpected flooding that can cause severe damage to the constructions and population in the downstream area. We present some results of the 3D analysis of the landslide produced in Lituya Bay (Alaska) on July 9th 1958 (Figure 7). The landslide was originated by an earthquake and Eugenio Oñate mobilized 90 millions tons of rocks that fell on the bay International Center for Numerical Methods originating a large wave that reached a hight on the opposed in Engineering (CIMNE), Spain slope of 524 mts. Figure 8 shows images of the simulation of the Universitat Politècnica de Catalunya (UPC), Spain Lituya Bay landslide with PFEM. PFEM results have been compared with observed values of the maximum water level in the north hill adjacent to the reservoir. The maximum water level in this hill obtained with PFEM was 551 mts. Fig. 10 - 3D simulation of the sinking of a boat induced by a hole in the side of the hull This is 5% higher than the value of 524 mts. observed experimentally. The maximum height location differs in 300 mts from the observed value. In the south slope the maximum water Fig. 11 - 3D simulation of a boat colliding with five ice blocks
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14 - Newsletter EnginSoft Year 9 n°4
Frequency-Reconfigurable Microstrip Antenna for Software-Defined Radio The increasing demand for portable devices with wireless connectivity within a wide frequency spectrum presents an ambitious challenge for the designer of the RF front-end who has to manage different wireless standards (GSM, UMTS, WiMAX, WiFi, Bluetooth, LTE). Covering several frequency bands simultaneously with a single antenna can be a very demanding task, which is why the employment of many different antennas integrated in the device and the use of multiband or broadband antennas might be a feasible solution for the problem. The use of different antennas implies an increase of the overall cost and space requirements. Broadband antennas transmit and receive signals within a large bandwidth but they may suffer an unbearable deterioration of the signal to noise ratio and thus a reduction of the overall efficiency of the system. Moreover, the electromagnetic spectrum is a shared resource that is more and more congested with the increasing number of users of wireless devices and the further exploitation of the available frequencies by other services poses practical and regulatory difficulties. To cope with this problem, the employment of an unused part of the spectrum or the opportunistic and temporary use of a shared portion may offer new resources.
upgrade, without changing the controlled hardware. This ambitious objective imposes strict requirements to the capabilities of the device radio front-end especially in terms of the requested frequency agility necessary for the smart and dynamic adaptation to the wireless environment. In particular, severe constraints are placed on critical components such as filters, matching networks and antennas. The SDR architecture requires a reconfigurable antenna which is able to modify one, or a combination, of its fundamental radiation properties depending on the adopted scheme [6]. A radiating device can exhibit a frequency agility, which allows to set its instant working frequency, a change in pattern shape, or an alteration of the electric field polarization. The reconfiguration is obtained by adjusting the path of currents on the antenna or even by altering the geometry of the radiating device. The three aforementioned degrees of reconfigurability can be realized by recurring to different technologies among which electrical RF switches such as PIN diodes and varactors, photoconductive elements or MEMS. Different kinds of antennas have been proposed for the enhancement of the SDR radio frontend including PIFAs, monopoles and patches.
The Cognitive Radio (CR) concept has been proposed as a Within this framework, we have recently developed a solution since the related CR radio network is able to evaluate reconfigurable microstrip patch antenna by using PIN diodes the instant occupancy of spectrum and decides on this basis as RF switches whose biasing network is how to allocate services on temporarily software-controlled via a PIC unoccupied parts of the EM spectrum. microcontroller. The microstrip patch This recent paradigm of communication antenna has been chosen for its low allows an efficient spectrum usage but profile, robustness and easy also poses some challenges, with regard manufacturing. The aim is to obtain an to hardware and software, which have antenna with a reconfigurable motivated the rise of the Software frequency response between 850 MHz Defined Radio (SDR) concept during the and 3.5 GHz by simply changing the last years. A device based on SDR is an state of the RF switches. After a integrated system which must exhibit preliminary optimization study based on extreme hardware performance to the cavity model of the patch antenna, support the necessary software-based we have considered the configuration signal processing and guarantee the shown in Fig. 1 in which five PIN diodes desired flexibility. The final goal is Fig. 1 - Top view of the frequency-reconfigurable microstrip patch antenna. The continuous circles are able to guarantee a proper sweep of therefore to implement most of the radio indicate group#1 whereas dashed circles designate the working frequency. The positions of system in software, easy to update or group#2.
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the RF switches have been chosen by inspecting the path of the currents on the patch surface to individuate the most suitable placement of the diodes to guarantee the current flow. The overall size of the patch antenna is 84 mm × 70 mm. It is worthwhile to mention that the size of each element in the antenna and the position of the PIN diodes were chosen under two imposed constraints. First of all, in order to reduce the complexity of the design, we aimed at a configuration where all the RF-switch biasing lines had to be placed on the top layer of the antenna substrate, avoiding any cut in the ground plane. Next, we also searched for a solution without any matching network thus requiring in each RF-switch state an impedance close to the 50 Ohm of the feeding line. Two shorting pins with a 1.0-mm-diameter were inserted as illustrated in Fig. 1, the former in one of the outer sections and the latter in the inner element. To obtain a correct evaluation of the antenna behavior, the diodes have been considered by using their circuit model in the Ansoft HFSS simulations (Fig. 2) instead of substituting them as an open circuit in the 'Off' case and as a short circuit when in 'On' state. The employed PIN diode is an Avago HSMP-4890 which presents Rs = 2.5 Ohm, L = 1 nH, CT = 0.3 pF and RP in the order of KOhm. The PIN diodes were placed by using silver conductive epoxy to avoid overheating of the device. Fig. 2 - PIN diode circuit In our design the five PIN diodes model for the 'On' state (a) have been divided into two groups and 'Off' state (b). (continuous and dashed circles as shown in Fig.1) thus providing four possible configurations. Each group allows current to flow when the diodes are in 'On' state whereas the propagation of the RF signal is interrupted when they are set to 'Off' state. The biasing network comprises two lines on the top of the dielectric substrate which connect each of the outer sections of the patch to the DC source. A RF block is necessary to isolate the RF and DC source on these biasing lines. Moreover, the inner element of the antenna and the other one inside the simil-loop element are connected to the ground plane by using the 1.0-mm-diameter via. This configuration allows modifying the state of the two RF-switch groups by simply changing the voltage between the ground plane and the two lines connected to each antenna side. In order to change on demand the instantaneous frequency, we have programmed a PIC16F688 flash microcontroller to switch among the four possible configurations described above and we have Fig. 3 - The antenna configuration is completely software-controlled by using the directly connected the PC which operates on the PIC microcontroller prototype board to a to change the state of PIN diodes.
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Fig. 4 - Frequency response of the antenna when PIN diodes belonging to group#2 are in 'On' state and others are in 'Off' state.
laptop through an USB interface (Fig. 3). Therefore the activation and deactivation of the RF switches is performed by a microcontroller which can change the working frequency on the basis of the information collected by another antenna (sensing antenna) which is scouting the available frequency slots, as proposed in the CR paradigm. A comparison between the simulated and measured S11 parameters for the configuration with group#1 in OFF state and group#2 in ON state is reported in Fig.4 and the agreement is satisfactory except for some frequency shifts which could be attributed to discrete component tolerances and soldering effects.
Fig. 5 - Comparison between the simulated (continuous line) and measured (dashed line with triangles) radiation patterns at 850 MHz: φ = 0 deg., φ = 90 deg.
The simulated and measured patterns on the xz (φ = 0) and yz (φ = 90) planes are reported in Fig. 5. From the inspection of the results it is apparent that there is no significant distortion of the antenna pattern caused by the PIC microcontroller and the biasing lines. Ing. Simone Genovesi, Prof. Agostino Monorchio Microwave and Radiation Lab., Dip. Ingegneria dell'Informazione (www.mrlab.it) Università di Pisa For more information, please contact: [email protected][email protected]
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16 - Newsletter EnginSoft Year 9 n°4
ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design In today’s aircraft thermal design, we can observe a trend towards electronics systems integration characterized by higher heat densities and a more frequent use of composite primary structures. All these factors require robust thermal management and thermal architecture design already at the preliminary design stages. The thermal architecture will have to be developed in order to mitigate thermal risks for temperature-sensitive equipment as well as to limit the aircraft systems overdesign. The improvement and optimization of the thermal architecture is regarded as one of the key success factors for future aircraft developments. It requires a complete pyramid of simulation tasks to be set up, from the individual equipment to aircraft section simulation, to the global aircraft thermal analysis. Many difficulties arise from this simulation framework due to the variety of physical models, partners, techniques and tools used at each level of the pyramid.
In this context, the aim of this paper is to describe an Environmental Control System design approach as applied in Alenia Aermacchi. The main technical challenges addressed in this paper are: • Air conditioning pack architecture design • Air distribution line design and trade-off study, • Multidisciplinary optimization of the air distribution system components • A/C cabin thermal environment evaluation and occupants’ thermal comfort. Background The air conditioning system is designed in such a way that it maintains the air within the pressurized fuselage
Fig. 2 - Thermal aircraft schematic
Fig. 1 - A/C air conditioning pack and air distribution system
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Table 1 - Electrical equipment dissipated power
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compartment at the required level of pressure, temperature, flow rate and purity. The air is supplied to the system from the engine compressor, the hot compressed air is cooled and conditioned in the air conditioning pack before being distributed to the various compartments through the air conditioning system (see Figure 1).
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As shown in Figure 4, the standard air condition pack architecture has been considered. Figure 4 illustrates also the mono-dimensional model built in LMS Amesim. The heat exchanger mono-dimensional model (low fidelity model) has been validated by comparing its results with CFD model results (high fidelity model). In Figure 5, we can see the validation analysis results.
Accordingly, in order to guarantee a comfortable A/C cabin environment, it is necessary to design and optimize the air conditioning pack and air distribution system. Air conditioning pack architecture design Requirements This study focuses on the following requirements: • A/C schematic configuration (see Figure). • Thermo-acoustic insulation U factor. • Electrical equipment dissipated power (see Table 1). • Temperature requirements for cabin/ cockpit. • Environmental envelope (see Figure 3). • The certification and performance requirements of ECS are reported below: o Minimum fresh flow per passenger: 0.55 lb/min. o Minimum fresh flow per crew member: 10 cfm. o Minimum fresh flow per galley 15 cfm. o Maximum ratio recirculation / total flow 0.4. o Maximum fresh flow per passenger/crew member for single pack operations 0.4. o Cabin stabilized temperature between 21°C -27°C. o Cockpit stabilized temperature between 21°C-27°C. Methodology The design of the air conditioning pack architecture has been reached through the following steps: • Definition of air conditioning pack monodimensional model. • Definition and validation of heat exchanger mono-dimensional model. • Definition of A/C cabin thermal monodimensional model. • Optimization of heat exchanger design, in order to meet certification and performance requirements.
Fig. 3 - Environmental envelope
Fig. 4 - ECS pack 1D- model
Fig. 5 - Heat exchanger size
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18 - Newsletter EnginSoft Year 9 n°4 • Steady state, cruise cold day (40 kft, -70 °C, Mach 0.85, 20% passengers) The heat exchanger has been defined in terms of its geometrical characteristics and number of plates. As shown in Figure 7, the analysis results confirm the compliance of the air conditioning pack architecture with the certification and performance requirements.
Fig. 6 - A/C mono-dimensional thermal model
Air distribution line design and trade-off study In order to determine the air conditioning pack architecture, the second step focused on the definition of the air distribution system. The latter depends on the following aspects: • Performance in terms of pressure losses. • Integration in aircraft. • Reliability and maintainability. Two different architectures have been analyzed. The first one (Architecture A) shown in Figure 8 is a parallel architecture composed of an underfloor line and a low pressure air distribution line that allow to distribute the airflow coming from the mixing chamber in parallel through the risers.
Fig. 7 - Performance of air conditioning pack
Fig. 8 - Air distribution system CAD model – Architecture A
Fig. 10 - Mono-dimensional model Architecture A.
Fig. 9 - Air distribution system CAD model – Architecture B
In order to design the air cycle machine and heat exchanger, the cabin aircraft mono-dimensional thermal model shown in Figure 6 has been built. It allowed to evaluate the cabin thermal environment and hence the compliance with varying pack performance depending on the heat exchanger design. The operating conditions analysed have been: • Steady state, ground hot day (ISA+25, 100% passengers) • Steady state, ground cold day (ISA-55, 20% passengers) • Steady state, cruise hot day (40 kft, -35°C, Mach 0.85, 100% passengers)
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Fig. 11 - Mono-dimensional modelArchitecture B.
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As boundary conditions we assumed the data reported below in various flight conditions, then the steady state analysis has been carried out: • Temperature, air flow, pressure and humidity coming from the air conditioning pack. • External conditions in terms of temperature. • Equipment and light heat load. • Passengers heat load. Figure 12 shows the analysis results in terms of pressure drop vs mass flow curve. In particular, the results highlight that the air distribution system pressure losses of Architecture A are higher than those of Architecture B.
Fig. 12 - Pressure loss vs massflow curves
The second one (Architecture B) shown in Figure 9 is a sequential architecture where the under floor is much limited, and the cabin air distribution system is developed above the floor. Starting from the CAD model shown above, a monodimensional model for each architecture has been built in LMS Amesim (see Figures 10 and 11). The mono-dimensional models are composed of the following parts: • Connection with air conditioning pack mono-dimensional model. • Cockpit line • Cabin line • Simplified A/C thermal model as thermal node. • Internal macro that allows to simulate the physiology of the passengers in terms of heat load and humidity released.
Fig. 13 - Technical performance measure
A comparison analysis has been performed by means of a Technical Performance Measure (TPM) methodology. First, all of the key requirements (performance, system integration in the aircraft, RMT) have been defined, categorized and weighted according to their degree of importance. Key factors and preferences have been established on the basis of Alenia’s experiences. Normalized weights of 0-1 range have been assigned as per the above to each key requirement. Then, each requirement has been split into sub-requirements, as follows: • Performance: o Pressure loss. • System Integration in the aircraft: o Influence on cabin noise; o Weight; o Ease of installation. • RMT o Reliability; o Maintainability. Each sub-requirement has been weighted according to its degree of importance compared to the others. Then, each weight has been normalized in absolute terms, in accordance with the key requirements. Also a score has been assigned to each sub-requirement, as follows: • 1 = VERY POOR: the proposed solution does not meet the system’s requirements; • 2 = POOR: the proposed solution does not meet the system’s requirements but the requirement deviation is acceptable;
Fig. 14 - CAD model for Outlet
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20 - Newsletter EnginSoft Year 9 n°4
Fig. 15 - Parametric model
• 3 = ACCEPTABLE: the proposed solution meets the system’s requirements, but with some risks. • 4= GOOD: the proposed solution meets the system’s requirements. Subsequently, attributes, weights and scores have been allocated, the quantitative frame which builds a rational evaluation has been defined, calculating the relevant weighted score for each sub-requirement. Figure 13 shows details of the TPM comparison analysis results. Following the outcome of the TPM approach, the results of architecture A of the air distribution system are preferred. Multidisciplinary optimization of air distribution system components The shape optimization of the air vent outlet has been carried out through the following phases: 1. Mesh accuracy study 2. Input sensitivity study 3. Design of Experiment (DOE) Analysis 4. Optimization 5. Automatic updating of the party in the product Design specifications Based on the flow of incoming air assigned to the maximum operative mass flow rate, the shape of the air vent outlet has been optimized (Figure 14) with the objective of minimizing pressure losses and noise levels. To achieve these goals, the geometry for the surface connection between the inlet and outlet of the nozzle has been parameterized.
Among the geometric parameters that were evaluated for the optimization is the angle Alpha; it is important to mention that this angle is formed by the axis coming from the centre of the inlet and the centre of the outlet, it changes the direction in which the air flow enters the cabin. Parameterization For the parameterization 6 points have been identified; these 6 points are located on the intersection of a virtual plane perpendicular to the line joining the centres of the inlet and the exit outlet. The 6 splines in Figure 15 have been initially identified as points A, B, C, D, E, F. As these point change their locations, the area of the opening will be adapted for the purpose of the optimization. Based on this configuration and by changing the location of the points, it becomes possible to update the area of the opening and in this way to modify the purpose of the optimization. modeFRONTIER Model In the modeFRONTIER model the geometric inputs are held constant while varying only the parametric data for the CAE model. The process flow consists of three blocks: 1. CATIA process: it opens the file CatiaV5 CATPart geometry of the nozzle, then it converts files into IGS and sends them to the next process. 2. STAR Process: StarCCM+ runs a mesh with Base Size Length which is assigned to the CAE_Input, then it automatically performs the calculations. It estimates the time taken (CPU_Time), and sends the simulation file (SIMfile) for the next process. 3. Process PostPRO: StarCCM+ checks for the simulation file, and if there are further calculations to determine the pressure and noise levels, in particular, according to the PostPRO_Input, a visual representation is saved in a jpeg file containing the pressure, the speed or noise level, as well as images of the mesh and the graph of the residue. The variables monitored are CPU processing time in seconds, CPU_Time, and total pressures in Pascal in and out of the nozzle: p_in p_out respectively.
Fig. 16 - modeFRONTIER model for shape and noise optimization of the outlets
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Design Of Experiment (DOE) Analysis In modeFRONTIER (whose workflow is shown in Figure 16) a DOE analysis has been performed taking into account the 3 free parameters dx_CF, dy_AB, and dy_DE, while, dx_AB, dx_DE, and dy_CF remain constant or the abscissas of points A, B, D and E. The ordinates of tpoints C and F remain stationary as assigned by the geometry.
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Table 2 - Table of results for optimal pressure and optimal noise reduction based on DOE
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Table 3 - MDO results based on the NSGA-II analysis
The range of variations of the free parametersis as follows: • dx_CF varies from -5 mm to +25 mm in steps of 10 mm (5 mm, +5 mm, +15 mm, +25 mm) • dy_AB ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) • dy_DE ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) The challenge of the optimization has been a multidisciplinary and multi-objective problem: the disciplines involved have been fluid dynamics and acoustics, the objectives were minimizing the pressure drop (p_in - p_out) and minimizing the level of noise emitted from outlets and walls.
Fig. 18 - Parallel Coordinates Chart optimization
Fig. 18 - Acoustic analysis for the outlet Fig. 17 - Parallel Coordinates Diagram for the restriction of the domain space of pressure loss and noise
Results A 4 level full factorial DOE has been carried out on the 3 variables, which means that 64 configurations have been tested (43 = 64 experiments). Following are the results which represent a significant improvement to the previously adopted design. The minimum pressure drop (corresponding to the configuration process number 9) and the minimum sound level (corresponding to the configuration process number 59) are shown in Table 2. From the table, it becomes clear that the two objectives cannot be achieved simultaneously, as the minimum pressure drop is far from the minimum level of noise produced by the walls (Table 2). Therefore, the analysis moved on to a Multidisciplinary Design Optimization MDO. Outlet MDO To refine the research of the investigation it has been decided to filter the results by imposing the limits of acceptance for the pressure drop in relation to the level of noise emitted from the walls. The filtering action narrowed the range of variations. This effect is shown in the filters operating diagrams in Figure 17, where the parallel coordinates were
Fig. 19 - Outlet CFD analysis for pressure drop
reduced to a range of 3 to 28 dB noise levels and a maximum pressure drop of 4 Pa. As before, the three parameters that vary have been dx_CF, and dy_AB dy_DE, while the other 3 parameters, dx_AB, and dx_DE dy_CF, remain constant, or the abscissas of points A, B, D and E. • dx_CF ranges from +12.5 mm to +25.0 mm in steps of 2.5 mm • dy_AB varies from -2.5 mm to +12.5 mm in steps of 2.5 mm • dy_DE varies from -2.5 mm to +12.5 mm in steps of 2.5 mm The optimization has been performed by implementing the Non-dominated Sorting Genetic Algorithm II (NSGA-II) with
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22 - Newsletter EnginSoft Year 9 n°4 treatment) of roughly 2 million cells has been constructed. • Boundary condition definition: all operating conditions. In this paper, we show the results of the boundary conditions, they are reported in Figure 20. Furthermore, an internal macro has been developed and embedded into StarCCM+ in order to simulate the physiology of the passenger in terms of heat load and % of humidity released. • Physics model: steady state, KEpsilon with two layers, all Y+ wall treatment, multi-phase model (air/water), segregated flow with radiation model.
Fig. 20 - Simplified CAD model and Boundary condition
10 generations in a population of 8 configurations chosen from the best, previously tested in the DOE analysis. Results The results of the best iteration in minimum pressure drop (corresponding to the configuration process number 130) and in minimum sound level (corresponding to the configuration process number 82) are presented in Table 3.
The aim of the analysis has been the study of the A/C cabin, we have analyzed and verifyied the following parameters: • Velocity field (see Figure 21) • Relative humidity pattern (see Figure 22) • Temperature pattern in cabin zones (see Figure 23). • Cabin average temperature
The Parallel Coordinates in the diagram of Figure 18 illustrate the results for the r80 run configurations generated for the optimization. Figure 18 shows the acoustic FEA analysis, and Figure 19 shows the CFD pressure losses analysis. Evaluation of the A/C cabin thermal environment and the occupants’ thermal comfort Once the design of the air distribution system and of the air conditioning pack were completed, the final steps have been the evaluation of the cabin thermal environment and the passengers’ comfort assessment. This activity has been developed through the following steps: • Tri-dimensional cabin thermal model development. • Assemby of a complete mono-dimensional model. • Comparison between the two approaches. Tri-dimensional CFD cabin thermal model The tri-dimensional cabin thermal model has been developed in the StarCCM+ environment, through the following steps: • Domain definition: due to its symmetry, a 2 meter long section of the cabin has been analyzed. • Mesh construction: in order to study, in adequate detail, the distribution of velocity, temperature and humidity, a polyhedral mesh (with a prism layer for turbulence
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Fig. 21 - Velocity field
Fig. 22 - Relative humidity pattern
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temperature calculated with the CFD analysis is comparable with the average temperature calculated with the mono-dimensional model, assuming the same input conditions. The CFD model allowed to obtain a detailed evaluation of the cabin thermal environment, the temperature stratification, the stagnation zones, and the thermal environment near the passengers for evaluating the status of the passenger comfort. The mono-dimensional thermal model allowed, in a sufficiently accurate way, to obtain a fast evaluation of the cabin thermal environment in terms of average temperature and % of humidity. Fig. 23 - Temperature pattern
Passenger comfort requirements imposed by the aeronautical rules are: • Differential temperature between aft and forward side are not to exceed 2°C • Differential temperature between head and feet are not to exceed 3°C. • Differential temperature between left and right side are not to exceed 2°C. Considering as boundary conditions the data reported in Figure 20, our CFD model provides the following results: • Average relative humidity: 36.37% • Cabin average temperature: 23.8°C • As shown in Figure 23, the compliance with comfort requirements described above could be guaranteed. Complete ECS system mono-dimensional model. The complete mono-dimensional model has been obtained by linking the air conditioning pack model (see Figure 4) with the air distribution system model (see Figure 10), and with the A/C thermal model shown in Figure 6. The aim of the analysis was to study the A/C cabin thermal environment, analyzing and verifying the following parameters: • Average relative humidity • Cabin average temperature The analyses have been performed at different A/C and flight conditions. Considering as boundary conditions the data reported in Figure 20, our mono-dimensional model delivered the following results: • Average relative humidity: 40% • Cabin average temperature: 24.1°C. Results In order to evaluate the mono-dimensional model results (low fidelity model), its results have been compared with the CFD tri-dimensional model results (high fidelity model). The performed analysis has highlighted that the average
Conclusions Various new frontiers are currently emerging in the aerospace industry. They require new initiatives and approaches for the role of engineering design and analysis, mainly due to the profound knowledge of the importance of cross-firms and cross-disciplines collaboration in large scale engineering design processes, such as aircraft design. This kind of collaboration and interaction is now more possible than ever before due to the current state of digitization of engineering design data, an IT infrastructure that enables a universal communication of data, the current engineering platforms which support collaboration, and the increasing computational power, which allows us to integrate multidiscipline, multi-physics and engineering data in one shared environment. This state-of-art design environment is leading to a new opportunity, and to a challenge. As the present study shows, process integration between different design disciplines is an essential factor for automating design processes. The design process presented in this paper is actually used in the Environmental Control System department of Alenia Aermacchi, where fluid dynamic problems are approached with innovative tools and innovative methodologies that allow to define the architecture and to optimize the performance from the early stages of the system design. The described approach allowed to achieve the following reported goals: • Reduction/elimination of physical tests and related costs during the development phase. • Minimization of certification tests. • Minimization of risks and costs linked to the re-design of parts in the manufacturing phase. Alenia Aermacchi S.p.A. – G. Mirra, P. Borrelli, A. Romano Politecnico di Torino – M. Tosetti, L. Pace Università del Salento – B. Palamà, A. Camillò For more information: Francesco Franchini, EnginSoft [email protected]
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24 - Newsletter EnginSoft Year 9 n°4
How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor return stable coupling of fixed parts, adequate freedom of moving parts and appropriate room to house electrical parts. For simplicity, we will call “functioning measurements” all those the contactor dimensions from which its reliable operation depends. In other words, if one or more functioning measurements is not comprised between assigned limits, the contactor assembly does not work properly and has to be rejected. Lovato Electric has been a prestigious Italian company operating Generally speaking, overall dimensions (including the in the electromechanical and electronic components market for functioning measurements) of a multi-part assembly depend on more than 90 years. Its wide catalog includes magneto-electric how both surfaces and edges of adjacent parts touch switches, contactors, sensors, digital multi-meters, soft-starters, themselves. From this point of view, the study of the assembly relays, automatic power factor correctors and other devices. Top geometrical properties becomes a tridimensional problem, whose quality, reliability and product variety make Lovato Electric a complexity grows with the number of contacts and shape of the star player in the world market. Company success is gained involved features. If parts had nominal shape, then the through constant valorization of internal competences and assembly would be univocally determined and solved by using parallel effective collaboration with customers and suppliers. any CAD tool. Real assembly conditions are far from the ideal In a past engineering service, EnginSoft was requested by ones, because real geometries exhibit a certain dispersion due Lovato Electric to investigate how the operation of an to the manufacturing processes. As a consequence, the assembly electromechanical contactor is influenced by dimensional and output is no longer univocally determinable and functioning geometrical tolerances of its components (GD&T analysis). measurements become dispersed as well. The contactor designer Electromechanical contactors constitute a relevant fraction of controls and limits the variability of the functional Lovato Electric production, so that the topic was perceived as of measurements (trying to keep them between the acceptance primary importance. limits) by assigning proper An electromechanical contactor is a dimensional and geometrical compact device including an tolerances to the components. The electromagnetic actuator investigation of how tolerances affect mechanically connected to a set of the dispersion of the functioning contacts. When the command signal measurements is carried out through a (a low power current) activates the statistical approach. internal inductor, a piston moves and change the connected contact status. The contactor that has been analyzed in the consulting service is composed Typically, this device is used to break a power circuit from changes by existing parts (i.e. taken from other production lines) and specifically location, without manually accessing designed new parts. EnginSoft the switch. The contactor is contribution has made possible to composed by both plastic and predict both mean values and metallic components held together by dispersions of the 5 functioning snapfeatures and screws. Plastic parts are manufactured by injection dimensions selected by the customer and shown in Figure 1. At the same molding process, while metallic parts time, an extensive sensitivity analysis are manufactured by cold forming of has made possible to identify the sheets. The contactor works reliably if factors influencing these dimensions, the assembly process creates both which are the key information to precise clearances and precise assess corrective strategies in case of interferences between parts, where unsatisfying distribution of the they are necessary. Fig. 1 - Contactor section highlighting the 5 outputs. Indeed, these geometrical conditions functioning measurements
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The service was completed through different tasks. First, the 3D CAD model was analyzed in detail to understand how the components interact and to select the surfaces involved in the contacts. Then, the dimensional chains were written accordingly. Each dimensional chain provides a vectorial representation of the geometrical relationships between component dimensions and functional measurements. For the analyzed device, it was found that 35 dimensions (among hundreds available) were affecting the functional measurements. As expected, the 5 dimensional chains resulted to be interdependent, since some dimensions were simultaneously included in more than one relationship. At the end of the problem definition, a virtual model of the contactor was developed, and the values of the 5 functioning measurements were calculated. A model used to investigate GD&T problems needs to faithfully reproduce geometrical interactions between parts. In order to meet such requirement, the virtual assembly is performed by putting into contact both surfaces and edges, instead of aligning planes and axes as we normally do in a CAD environment. The hardest phase of such work, which is also the deeper added value of this service, is really the mathematical description of the tridimensional interactions between component features. The model is finally parameterized, so that it includes the variability (in terms of position and size) of all geometrical details involved in the contact definition. Virtual measurements can be taken easily, in accordance to the model purposes. It is not difficult to see that a model with the mentioned characteristics, virtually reproduces any possible configuration of the multi-part assembly. From a different perspective, we could look at the model as to a numerical representation of the dimensional chains previously identified: it correlates the outputs (i.e. the functioning measurements), to the inputs (i.e. the component dimensions). The statistical investigation of the GD&T problem was carried out by assigning a normal distribution to each dimension of the components. This was an arbitrary choice, since we did not have information about. Obviously, we could have assigned any kind of distribution to each dimension. Mean values were picked in the middle of the corresponding tolerance ranges, while standard deviations were assumed as equal to 1/6 of the widths. These assumptions relate to the quality of the manufacturing processes we consider. By filling the tolerance range with 6 standard deviations, we implicitly assume that just 1 component out of every 370 has the considered dimension out of its tolerance. We investigated how tolerance effects propagate to the functioning dimensions, by generating a huge number of device configurations in a limited time. Distributions of the 5 outputs were then compared with the given acceptance limits, in order to identify the percentages of devices fulfilling the requirements. Main results are collected in Figure 2, the distributions of the 5 functioning measurements are compared to the corresponding requirements. All distributions are still of normal type, with symmetric shape. Plots highlight that significant fractions of the entire production are not meeting the operational requirements.
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Fig. 2 - Distributions of functioning measurements in the virtual production
The probability for a contactor to not be accepted after assembly is about 37%, mainly because the measurement n. 4 goes out of its acceptance limits. Plots of Figure 2 shows that non conformities can be caused by both an excessive width of the distribution (FUNC.MEAS.3) or a misalignement of the mean value with the acceptance range (FUNC.MEAS.2 and FUNC.MEAS.4). The statistical sensitivity analysis carried out on the population has made possible to select the dimensions (among the 35 involved) with the highest influence on the 5 outputs. Thus, appropriate adjustments were assessed to reduce the risk of non-conformity. In particular, the mean value of FUNC.MEAS.4 was moved to right (almost making null the area lying out of the acceptance bounds) by adjusting the nominal value of 2 component dimensions. This result really highlights the power of the GD&T analysis: an assembly issue is fixed with no need to narrow tolerance ranges. In other words, the reduction of rejected devices is obtained without increasing manufacturing costs. In this example, the collaboration between Lovato Electric and EnginSoft has returned valuable benefits. EnginSoft has simulated the assembly process through advanced numerical tools, providing crucial information about the relationships between component dimensions and final contactor performances. As issues were identified, proper corrections were planned and verified immediately. This has allowed Lovato Electric to shorten the physical prototyping phase, which turned into an effective reduction of overall production costs. For more information: Fabiano Maggio - EnginSoft [email protected]
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26 - Newsletter EnginSoft Year 9 n°4
Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot A novel slot-coupling feeding technique for wideband dualpolarized patch antennas is presented. A square patch is fed through a square ring slot excited by two non-overlapping feeding lines printed on the same side of a single-layer substrate. Reflection coefficient, port isolation and radiation patterns are evaluated by numerical simulations with ANSYS Designer and compared with measurements on an antenna prototype operating at the WiMAXTM 3.3-3.8 GHz frequency band (14% impedance bandwidth). Based on the slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly-polarized square patches, a single-feed circularly-polarized square patch, also in a stacked version, a 2x2 array of dual-polarized circular patches fed through a circular slot, a 2x1 array of stacked square patches fed through square slots. 1. INTRODUCTION The last years have seen a significant exploitation of printed antenna technology in mass production of planar arrays for base stations and subscriber units of cellular communication systems. Indeed, microstrip antennas are characterized by low profile, light weight, easy construction, and high flexibility in designing shaped-beam and multiband antennas. Although there are some considerable concerns regarding the microstrip antenna inherently resonant feature, a number of efficient techniques have been proposed to meet the large impedance bandwidth requirement of modern broadband communication systems. Furthermore, several dual-polarized patch
Fig. 1 - Some configurations of dual-polarized slot-coupled patch antennas, with different positions of the two coupling slots with respect to the patch center. Feeding lines with the same color are printed on the same side of the dielectric slab; in X1 an air bridge is needed to avoid line overlapping.
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configurations have been designed to be used as radiators in arrays for polarization-diversity based radio links. A common feeding technique for wideband antennas is based on slotcoupling, where a microstrip line is coupled to the radiating patch through a slot in a metallic ground plane, as first proposed by D.M. Pozar. Slot-coupled patches can exhibit a quite large impedance bandwidth at the cost of an affordable construction complexity, and allow for more space for the feed network with respect to microstrip fed arrays (the latter being an important need especially for dual-polarized dense phased arrays). Moreover, the metallic slot plane prevents the spurious radiation from the feed network and then reduces the amplitude of the cross-polar components. Finally, the two-layer structure allows for using a thick low-permittivity substrate for the patch (which guarantees a larger impedance bandwidth and a higher efficiency) and a thin high-permittivity substrate for the feed circuitry (as required to suppress radiation from the feed line and to save space for the feed circuitry). To extend the singlefeed, single-polarization design to the dual-polarization antenna design, a large number of aperture-coupled patch antennas have been presented in the open literature (most of them are shown in Figure 1). Dual-polarized microstrip antennas require the excitation of the two orthogonal fundamental modes of a microstrip patch. Dualmode excitation can be obtained by coupling the radiating patch to the feeding network through two orthogonal slots in a metallic ground plane: either a cross-shaped slot or separated orthogonal slots have been used. Besides gain and radiation pattern values, design concerns are also about the port isolation and the cross-polarization level, since they impact on the communication system performance. Both above properties are markedly related to the electrical and the geometrical symmetry properties of the antenna layout with respect to the principal radiation planes. Moreover, a symmetry property of the antenna with respect to the two input ports is also a valuable feature, as in this case the two polarization ports exhibit identical impedance and radiation characteristics. In this paper a novel dual-polarized slot-coupled feeding technique is presented. With respect to other slot-coupling feeding techniques for dual-polarized patch antennas, the proposed configuration exhibits a simple structure and a valuable
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symmetry property with respect to the two feeding ports, while preserving a satisfying isolation between them (greater than 20 dB). A square patch is coupled to a pair of microstrip feeding lines by a square ring slot realized in a metallic ground plane, and both feeding lines are printed on the same side of a singlelayer substrate. Antenna layout performance is shown for a design relevant to a patch operating in the 3.3-3.8 GHz WiMAXTM frequency band. Simulation data agree with measurements on an antenna prototype. The proposed coupling technique is suitable for the design of large planar arrays with dual linear polarizations (vertical/horizontal polarizations or 45° slanted polarizations). Dual circular polarization can also be implemented by adding a 90° hybrid coupler. ANSYS Designer is the electromagnetic simulator code used for all patch antennas design. The physical quantities taken into account in all projects are the reflection coefficient, the isolation between the two channels in the dual polarization configurations, the axial ratio for circular polarized antennas, the gain and directivity, the 3D radiation patterns and the Eθ and Eφ components in the two principal antenna planes, the back radiation, the side lobes level. Each antenna element is parameterized in order to analyze each parameter effect on the antenna performance and in order to simplify the optimization process. For example, thanks to the parameterization, modifying the distance between two array elements elements is not necessary to re-design the feeding network. The simulated results are very close to the prototype measurements, also avoiding systematic errors that are committed in the measurement process, as implementation prototype errors, welds discontinuities, etc. The article is organized as follows. The novel slot-coupling feeding technique and its working principle are illustrated in Section 2 together with simulated results obtained with a fullwave commercial tool and with measurements on an antenna prototype. Section 3 describes the new feeding technique applications to some circular polarized arrays and stacked antenna. Finally, concluding remarks are drawn in Section 4. 2. A Square Ring Slot Feeding Technique The novel dual-polarized slot-coupled patch antenna fed through a square ring slot is shown in Figure 2. Both feeding lines are printed on the same side of a single layer substrate and a metallic reflector is added to limit the back radiation. It is apparent that the layout is symmetric with respect to the two input ports, which means that identical radiation and input impedance properties are expected. The latter represents a useful feature when designing a circular polarized patch (requiring an additional feeding circuit to generate two signals with the same amplitude and a 90° phase shift), or when designing the feeding network of a dual-polarized array. Moreover, since the slot and patch phase centers overlap, the radiation pattern main direction is not depointing at any frequency. The radiating elements are fed in ANSYS Designer through an edge port inserted between the microstrip line (printed on the dielectric substrate upper surface) and the antenna ground plane (on the other side of the same substrate). The proposed
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Fig. 2 - The square patch fed through a square ring slot: (a) stackup and (b) layout. Dimension of the geometrical parameters for a 3.5 GHz WiMAXTM antenna: P=22 mm, L=17 mm, K=0.5 mm, W1=2.5 mm, W2=3.7 mm, S1=2 mm, S2=6 mm, H1=22 mm, H2=11 mm.
feeding technique allows to simultaneously feed the patch by using two orthogonal microstrip lines, furthermore the above lines can be properly connected to get circular polarization. To evaluate the isolation between these two channels and to analyze separately the Eθ and Eφ components contribution generated by the two microstrip lines, it was necessary to insert two edge ports. To show the working principle and the radiation properties of the proposed slot-coupled patch, a sample antenna operating at the 3.3-3.8 GHz WiMAXTM frequency band has been designed, fabricated and characterized. It is worth noting that the proposed geometry can be used for any application requiring a planar dual-polarized antenna with a 10-15% fractional bandwidth (larger impedance bandwidth can be also obtained by adding a square stacked patch) and a 20 dB port isolation. In the sample antenna, both microstrip lines are printed on the same 90x90 mm2 Rogers RO4003 laminate (εr=3.55, tanδ=0.0027, thickness=1.524 mm), available in the ANSYS Designer material library. The low loss Roger RO4003 used for the antenna active part, although more expensive, allows to obtain higher antenna gain thanks to lower feeding line losses. Instead, the low cost FR4 was used to print the patches, electromagnetically coupled to the microstrip line. The stackup is shown in Figure 2a. The square ring slot has a perimeter of 68 mm (Figure 2b) and it is etched on the other side of the above substrate, namely on the metallic ground plane separating the feed lines from the square patch. As in other slot-coupled patch configurations, the ground plane prevents spurious radiation from the feed network and the length of the open-circuited stub behind the slot is optimized for input impedance tuning. A 160x160 mm2 square aluminum reflector is placed at a distance of 22 mm from the feed lines to reduce back radiation and increase the antenna gain. The 22x22 mm2 copper patch is printed on the bottom layer of a 90x90 mm2 FR4 laminate, which is 1.6 mm thick (it also acts as a cover for the antenna). The air gap between the patch and the slot plane is 11 mm thick. Figure 3 illustrates the electric field distribution inside the square ring slot when Port1 of the patch in Figure 2 is fed. It is apparent that the field distribution resembles that of the fundamental resonating mode of a ring slot. This is in agreement with the slot perimeter length that is close to the guided wavelength λg of a slotted line with the
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28 - Newsletter EnginSoft Year 9 n°4 same geometrical and electrical parameters as those of the slot: Oviedo. The frequency set for the mesh was thus chosen as 5 λg=66 mm at 3.5 GHz. The electric field distribution shown in GHz, which was a good compromise between mesh accuracy and Figure 3 reveals a number of interesting features. The side of simulation times (Figure 5). The sweep analysis was varied from the ring slot that is directly fed and that one parallel to it (i.e. 3000 to 4000 MHz. the vertical sides of the ring slot shown in Figure 2b) are both excited, and the electric field induced into the two slot sides Both measured and Designer simulated results for the reflection are in phase and with a similar amplitude; as a consequence, coefficient and port isolation are shown in Figure 6, and they due to above phase relationship and the symmetric position of exhibit a reasonable agreement. For both polarizations, the the vertical sides with respect to the reflection coefficient is less than -10 dB, patch center, the resonant mode of the from 3.3 GHz to 3.8 GHz (percentage patch (that one associated to Port1) is impedance bandwidth is 14%). The port properly excited and low crossisolation is greater than 20 dB in the whole polarization is expected. Moreover, the 3.5 GHz WiMAXTM frequency band. electric field distribution induced into the In Figure 7, the co-polar and cross-polar two sides of the slot orthogonal to the components of the radiation patterns, in the previous ones (i.e. the horizontal sides of θ=45° and θ=-45° radiation planes, are the ring slot shown in Figure 2b) are out shown, when Port2 is fed (indeed, dual-linear of phase and do not excite the orthogonal polarized antennas are usually used to resonant mode of the patch (that one Fig. 3 - Direction and amplitude of the electric implement base station antennas with ±45° associated to Port2). Finally, the induced field inside the square ring slot, when Port1 of slanted polarizations). Measured half power electric field does vanish close to the the antenna in Figure 2 is fed (ANSYS Designer beamwidth at 3.55 GHz is around 56° in both data). center of the horizontal sides of the slots; planes and cross-polar components are below
Fig. 4 - A square ring slot antenna prototype for 3.5 GHz WiMAXTM applications.
Fig. 5 - Antenna mesh at 5 GHz.
it means that a relatively high port isolation is expected when that point is used to couple the slot ring to the orthogonal feed line corresponding to Port2. It is worth noting that since the slot perimeter is less than the free-space wavelength (actually it is around a slot-line guided wavelength) and the patch perimeter is almost double the free-space wavelength, the whole square ring slot does always remain under the patch, for any design frequency. Finally, due to the perfect symmetry between the two ports, the same radiation patterns (in both E and H planes) and the same gain for the two ports are expected in the whole antenna frequency bandwidth. The presented novel layout can be seen as an advancement of “O” configuration in Figure 1. Indeed, it is apparent that the four-slot arrangement, symmetric with respect to the patch center, resembles the ring slot geometry. The significant difference is that in the novel configuration all four sides of the ring slot contribute effectively and correctly to the excitation of the two orthogonal fundamental patch resonant modes, while in the “O” configuration two of the four slots are parasitic elements. A 3.5 GHz WiMAXTM prototype (Figure 4) has been realized and measured in the anechoic chamber at the Department of Electrical Engineering of the University of
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Fig. 6 - Measured and simulated S-parameters of the square ring slot patch.
-18 dB in the broadside direction. Measured gain is between 8 dB and 8.7 dB in the band of interest (Figure 8). Similar results are obtained when Port1 is fed. 3. Square Ring Slot Technique Applications Basing on the ring-slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly polarized square patches (Figure 9), a single-feed circularly polarized square patch, also in a stacked
Fig. 7 - Measured and simulated co-polar and cross-polar components for the square slot patch in Figure 2, at f=3.55 GHz when Port2 is fed: (a) θ=45° plane and (b)θ=-45° plane.
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version (Figure 10), a 2x2 array of dualdesigned to increase the percentage polarized circular patches fed through a bandwidth up to 44.5% in order to be circular slot (Figure 11), a 2x1 array of used at base stations where wideband stacked square patches fed through square antennas are needed (e.g. base stations slots (Figure 12). In Figure 9, the sequentially for GSM, PCS, UMTS, WLAN applications). rotated 2x2 array prototype with a complete The simulation times, for all the microstrip feeding network is shown. Each antennas designed and presented in this dual-linear polarized patch has been fed paper, vary between 15 and 60 minutes, through a reactive 3 dB power divider in order depending on the antenna operating to have a single feeding line. The feeding band and the radiating elements number network consists of microstrip lines whose Fig. 8 - Measured and simulated gain of the in the configuration. The ANSYS Designer square ring slot patch in Figure 2, when Port2 lengths have been adjusted to achieve the is fed. simulation process has saved a lot of required 90° current phase difference time: the prototype procedure (up to between adjacent elements. To get a wide impedance and wide connectorization process) and measured process is very axial ratio bandwidth, a sequential rotation feeding technique onerous: the prototype process was about 60 minutes, the has been adopted. A single feed slot-coupling solution has radiation patterns measurements component for a single plane been applied to gain circular polarization. A meandered slot is at a single frequency was about 2 minutes). Then this procedure designed to excite two orthogonal modes and the same kind of was repeated for each plane, both the components and the perturbation is applied to the patch. To preserve the antenna entire band of interest. Moreover, it is necessary to take symmetry, two identical meanders have been added on two account of the entire prototyping and measurement cost (the opposite sides of the square ring. Both width and length of the materials cost, the instrumentation, the available facilities). It above slots have been optimized. To improve axial ratio was therefore fundamental to get to the measurement stage performance, a stacked solution has been proposed (Figure 10) with reliable projects, obtained with ANSYS Designer. to get a 12% 3 dB axial ratio bandwidth. Basing on Figure 9, the configuration shown in Figure 11 is 4. CONCLUSIONS designed with both circular slot and patch. The performances of A novel wideband slot-coupled patch fed through a square ring the two configurations are shown and compared for two slot has been presented and design criteria have been fabricated prototypes. Antennas shown in Figure 9 and Figure discussed. Owing to its simple structure, the patch described 11 have been designed to operate in the WiMAXTM frequency here can be used as the radiating element of medium and large band around 3.5 GHz. The configuration shown in Figure 12 is planar arrays with dual linear polarizations (vertical/horizontal a 2x1 array of square stacked patches. This antenna has been polarizations or ±45° slanted polarizations). Antenna performance in terms of port isolation and cross-polar component level has been shown through the design, fabrication and characterization of a patch operating at the 3.3-3.8 GHz WiMAXTM frequency band. A 20 dB port isolation has been obtained, in a 500 MHz frequency band (14% fractional bandwidth), with cross-polar level less than -18 dB at the broadside direction. We have also experienced that the final design of the proposed solution is a result of a trade-off between frequency bandwidth enlargement and isolation improvement. Impedance bandwidth enlargement can be Fig. 10 - Single-feed circularly polarized achieved by adding either stacked patches or other parasitic Fig. 9 - 2x2 array of dual-feed stacked square patch for 3.5 GHz circularly polarized square patches elements close to the main radiating patch, while preserving WiMAXTM applications. for 3.5 GHz WiMAXTM applications. the original symmetry properties. Finally, due to the symmetry of the antenna layout with respect to the two feed ports, good axial ratio performance can be obtained when it is used to radiate a circularly polarized field.
R. Caso, A. Buffi, P. Nepa - Department of Information Engineering, University of Pisa A. Serra - EnginSoft Fig. 11 - 2x2 array of dual-polarized circular patches fed through a circular slot for 3.5 GHz WiMAXTM applications.
Fig. 12 - 2x1 array of stacked square patches fed through square slots for GSM, PCS, UMTS, WLAN applications.
For more information: Andrea Serra, EnginSoft [email protected]
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30 - Newsletter EnginSoft Year 9 n°4
Grapheur for Material Selection In this article the criteria of mechanical behavior of the MCDM for Material selection woven textile composites during the draping and the further When multiple criteria from different disciplines are to be involved simulations and analysis are included in the process satisfied in a material selection problem, often complexities of the optimal design and decision making. For this purpose, the advanced software architecture of Grapheur for interactive optimization and MCDM is utilized. In this software the identified challenges of utilizing MCDM are improved via connecting the data mining/visualization and optimization through the user interaction. For the optimal Fig. 1 - Simulation of the draping process design of composites, with the aid of advancement of interdisciplinary and data analysis tools, a series of criteria including mechanical, electrical, chemical, cost, life cycle assessment and environmental aspects aspects can now be simultaneously considered. As one of the most efficient approaches, the MCDM applications can provide the ability to formulate and systematically Fig. 2 - A combination of four different simulation criteria including the compression, bend, compare different alternatives against the large stretch, and shear form the draping a) Mechanical modeling of the bending; the behavior of sets of design criteria. However, the mechanical textile under its weight is simulated by manipulating the related geometrical model within behavior of woven textiles during the draping the CAGD package. b) Geometrical model increase due to criteria conflicts. Many applications and process has not yet been fully integrated into the optimal algorithms of MCDM have been previously presented to deal design approaches of the MCDM algorithms. with decision conflicts often seen among design criteria in material selection. However, many of the identified Introduction In the integrated engineering design process and optimal drawbacks and challenges are associated with the applicability. design, the material selection for the composite can determine the durability, cost, and manufacturability of final products. The process of material selection begins with Draping indentifying multiple criteria properties of mechanical, The manufacturing of woven reinforced composites requires a electrical, chemical, thermal, environmental and life cycle forming stage so-called draping, in which the preforms take costs of candidate materials. However, the mechanical the required shapes. The main deformation mechanisms behavior of woven textiles during the draping process has during forming of woven reinforced composites are not yet been fully integrated into the optimal design compression, bend, stretch, and shear which cause changes approaches of the MCDM algorithms. in orientation of the fibers. Since fiber reorientation
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Fig. 3 - Geometrical modeling of double dome utilizing the Khabazi [11] algorithm.
influences the overall performance, it would be an important factor that should be taken into account along with the other criteria. Mechanical modeling and simulation of the draping The mechanical models of drape involve much higher computational cost when compared to the kinematic models; yet, they offer the benefit of representing the non-linear material behavior. Moreover the mechanical simulation, as the most promising technique, gives a real-life prediction of the fiber reorientation. Geometrical modeling and simulation of the woven textiles Moreover, of all the approaches for the geometrical modeling of woven textiles presented so far, the Spline-based methods are the most effective technique. In fact, the Spline-based geometrical representation of a real-life model of any type of flat-shaped woven textile, is realized by implementing the related computer-aided geometrical design (CAGD) code. However, the mathematical representation of a woven multiple-dome shape, in the practical scale, may not be computationally valid. In order to handle the computational complexity of geometrical modeling the multiple-dome woven shapes, utilizing the NURBS-based CAGD packages are essential. Khabazi introduced a generative algorithm for creating these complex geometries. His improved algorithm is capable of producing the whole mechanism of deformation with combining all details of compressed, bended stretched and sheared properties. It is assumed that if the mechanical behavior of a particular woven fabric of a particular type and material is identified then the final geometrical model of the draping could be very accurately approximated. In this
technique the defined mechanical mechanisms of a particular material, in this case glass fiber, is translated into a geometrical logic form integrated with the NURBS-based CAGD package through a process called scripting. Integration the MCDM-assisted material selection with draping simulation In order to select the best material of a woven textile, the draping simulation needs to be carried out for a number of draping degrees. The results of all the draping simulations of different drape angles are gathered as a challenge and opportunity Nowadays, more and more enterprises can afford to enlarge their data storage means at will. Information that a few years ago would have been thrown away is now kept in the main storage area, ready to be retrieved and analyzed. Enterprises are now discovering that they lack the means to draw insights from this large amount of data: while storage room builds up nicely, communications and processing power needed to extract useful information from data is beyond their reach. Such power is now made available thanks to parallel processing platforms such as Apache Foundation’s Hadoop, however their use remains a big challenge for most organizations. The LION difference: machine learning and optimization Consider a web server farm as used by many enterprises. Every webpage accessed by a visitor results in the addition of a line of text to a log file recording the instant of of the request, its source, and many other pieces of information (similar logs are produced by activity in social networks like Twitter, Facebook, etc). Server logs keep growing and, to avoid unusably large files, they are broken into smaller files and eventually moved to different disks. When the LIONsolver machine learning and optimization platform is combined with a Hadoop implementation for web log analysis, previously unknown patterns emerge that show the behavior of customers in a website. For example, event data,
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such as video views, email registrations, or literature downloads can be correlated to engagement (time on site), pages visited and interacted with (suggesting the efficacy of web design) and ultimately with purchase follow through. As shown below, LIONsolver drives the flow of data and computation in the Hadoop system, visualizes the results once they are made
available by the framework, develops models by 'learning from data' and suggests improving strategies. LIONsolver goes beyond simple visualizations to show correlations that impact business decisions to inform customer and content targeting, web design, business rules, and so on. For more information, visit http://lionsolver.com/ or contact us at [email protected]
Newsletter EnginSoft Year 9 n°4 -
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Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura Nello studio di processo di produzione per deformazione a caldo di una forcella in acciaio C25 è stato affrontato anche il problema della resistenza a frattura duttile degli stampi. Eseguendo una preventiva analisi del processo di produzione di una Forcella, è stato possibile valutare l’influenza dei diversi parametri dell’intero processo produttivo, successivamente sono state condotte analisi FEM delle diverse fasi di progetto per poter definire gli stati tensionali e deformativi del materiale in deformazione e degli stampi, mediante codice numerico. Si sono potute così valutare le diverse cause del fenomeno di bassa durata produttiva degli stampi, calcolando i valori di intensificazione delle tensioni nei punti in cui nella realtà si verifica l’innesco della cricca. E’ stata inoltre studiata l’ottimizzazione dell’intero processo, per ottenere un prodotto integro da difetti, un miglioramento del comportamento a fatica degli stampi ottenendo benefici produttivi sia economici che energetici. Introduzione I processi di lavorazione per deformazione plastica sono un campo di estremo interesse per le moderne tecniche CAE vista la complessità teorica dei singoli processi e l’influenza dei vari parametri. In particolare il processo di deformazione a caldo di acciaio in stampi chiusi è stato storicamente uno dei primi processi investigati attraverso le tecniche di simulazione numerica. Ciò soprattutto per l’elevato grado di ripetibilità della “massiva” produzione di dato processo e dei numerosi parametri in gioco. Un approccio di tipo FEM (Finite Element Method) è il più adatto allo studio del processo nel suo dettaglio, con la possibilità di previsione delle tensioni e delle deformazioni indotte dalla lavorazione per deformazione plastica a caldo. L’applicazione di tale metodologia è assai complessa, vista la non linearità di comportamento del materiale che viene schematizzato con un modello elasto-visco-plastico. Il problema che il tecnologo di produzione si trova ad affrontare è quello di definire le diverse fasi di stampaggio per trasformare il disegno del pezzo finito nel disegno del grezzo e della
cavità degli stampi, con un procedimento che segue diverse fasi di progetto. Lo stampaggio prevede un ciclo di lavoro molto complesso, con aspetti che richiedono competenza scientifica ed esperienza per la definizione delle diverse fasi in maniera corretta sia per l’ottenimento di un corretto manufatto esente da difetti, sia nella scelta della soluzione più economica. Lo studio condotto si prefigge l’obiettivo di dare un contributo significativo allo sviluppo di tecniche per la progettazione e l’ottimizzazione dei processi di lavorazione per deformazione di acciai. L’intero progetto ha lo scopo di poter migliorare il controllo del processo di deformazione, l’analisi delle difettosità, delle forze e delle sollecitazioni a fatica degli stampi su base ripetibile in ambiente produttivo della moderna realtà industriale. Il componente forgiato preso in esame è una forcella, organo meccanico di collegamento atto alla trasmissione di forze statiche e dinamiche, prodotto in tre passaggi: Preformatura, Abbozzatura e Finitura. Nella prima parte dell’attività si è esaminato lo stato dell’arte del processo di produzione del particolare preso in considerazione, conducendo studio FEM del processo reale: studio della parte “teorica” di processo, introduzione ed approfondimento delle basi della fisica, meccanica e strutturale per comprendere le dinamiche della deformazione plastica a caldo di un materiale metallico, le metodologie e le operazioni che li caratterizzano. Nell’ultima fase di stampaggio, Finitura, dopo un numero esiguo di prodotti, si riscontra nella realtà produttiva il fenomeno di rottura dello stampo superiore in una regione ben localizzata di concentrazione degli sforzi. Lo studio si è focalizzato sull’analisi di tale fenomeno, il quale inficiava la produttività reale del processo, ponendosi l’obiettivo di minimizzare il carico pressa necessario alla deformazione, e ottimizzare il binomio processo/prodotto variando le condizioni a contorno, nel pieno rispetto dei vincoli di completo riempimento e nulla difettologia sul forgiato finale.
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34 - Newsletter EnginSoft Year 9 n°4 L’ottimizzazione è stata condotta sull’intero processo, concatenando le diverse operazioni di forgiatura intimamente accoppiate con l’evoluzione termica del componente in deformazione e nelle fasi intermedie di passaggio da una all’altra operazione. I risultati hanno permesso di correlare la variazione dei principali parametri di processo ai benefici ottenuti: risparmio di materiale (benefit economico) e diminuzione di onerosità di processo (benefit energetico-economico-ecologico). Nella parte finale dello studio, ci si è concentrati nell’analisi di sollecitazione degli stampi con approccio disaccoppiato. Si è testato attraverso analisi FEM, dapprima la riproduzione di sollecitazione e plasticizzazione dello stampo nelle aree di innesco rottura, con verifica del numero di cicli e previsione di vita utile prima di arrivare a rottura duttile; in un secondo momento si è testato come le condizioni di ottimo apportassero significative migliorie anche al fenomeno di “rottura a fatica”. Processo di deformazione plastica a caldo Le lavorazioni per deformazioni plastica di materiali metallici hanno origini lontanissime nella storia della tecnica. Sottoposto all’azione di forze esterne tramite presse o magli, il materiale varia permanentemente la sua forma originale; tale trasformazione avviene allo stato solido-viscoso. I processi di lavorazione per deformazione possono essere suddivisi in: • primari, utilizzando materiale da fusione e ottenendo semilavorati commerciali destinati ad uso diretto o ad ulteriori deformazioni; • secondari, da prodotti di deformazione primaria si ottengono manufatti di forma e dimensioni finite.
stampaggio a caldo è una tipica lavorazione per produzione di grande serie. Di contro lo svantaggio è quello di necessitare di energia per il riscaldo, favorire l’ossidazione del metallo ed inoltre risulta difficile prevedere la precisione dimensionale ottenibile. La billetta iniziale è uno spezzone quadro (sezione 120x120 mm, raccordo R20, lunghezza 327 mm, peso 36 kg) proveniente da deformazione primaria, in C25/1.0406, il volume della billetta
Fig. 2 - Bielletta iniziale in C25. Forcella Forgiata - Prodotto Finito
tiene conto anche della maggiorazione della percentuale di perdita di materiale per ossidazione (calo termico); mentre il prodotto finale di forgiatura è una forcella di trasmissione meccanica (Fig.2). Lo spezzone di acciaio viene riscaldato in forno con lo scopo di arrivare alla temperatura idonea di stampaggio, che deve essere la più alta possibile, rimanendo tuttavia distante dal punto di La corretta progettazione dello stampaggio deve assicurare un fusione per evitare liquefazioni e bruciature di materiale: circa corretto e completo riempimento degli stampi, studiandone i parametri ed i fattori che lo influenzano: 1250°C. Tale temperatura deve essere maggiore di quella critica di transizione vetrosa per poter sfruttare la migliore deformabi• deformabilità e resistenza allo scorrimento; lità, il materiale a tale temperatura ha una caratteristica elasto• uso di lubrificanti; • temperatura della parte deformabile e degli stampi; visco-plastica. Il tempo che intercorre dall’uscita forno al primo step di deformazione provoca una caduta termica della superfi• forma del pezzo finale; • calcolo della forza necessaria. cie della billetta che scambia calore con l’aria circostante (minimizzazione del tempo di fuori forno). Nella maggior parte dei casi di processo di stampaggio è necesI processi di deformazione a caldo avvengono ad una temperasario deformare progressivamente il materiale di partenza, per tura maggiore della temperatura critica di ricristallizzazione, i garantire un riempimento accurato degli stampi e per ottenere vantaggi di tale metodo sono sia le minori forze e potenze riuna valida distribuzione delle fibre all’interno del prodotto finachieste, sia la possibilità di indurre grandi deformazioni e l’ottele. La non uniformità di deformazione influenza negativamente nimento di forme anche complesse, grazie alla maggior duttilità le caratteristiche meccaniche finali dello stampato, per cui eledei metalli alle alte temperature (Fig1). Limitando le forze nevata cura va profusa nello studio dell’intero processo. Spesso si cessarie e sfruttando la migliore deformabilità del materiale, lo necessita quindi di sbozzati intermedi la cui forma e dimensione è mediata tra lo spezzone iniziale e lo stampato finale, attraverso stampi sbozzatori, con caratteristiche simili a quelli finitori, possono essere ottenuti tali sbozzati. Il processo industriale reale è uno stampaggio in tre fasi deformative: Preforma, Abbozzatura e Finitura. Tutte e tre le fasi di Fig. 1 - Deformazione Plastica di un Materiale metallico e proprietà. Effetti dell’incrudimento sulle stampaggio sono ottenute dall’azione della caratteristiche meccaniche. Effetti della temperatura sulle caratteristiche meccaniche di un materiale Pressa Meccanica (Fig.3) che impartisce il metallico.
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Newsletter EnginSoft Year 9 n°4 -
Fig. 3 - Pressa Meccanica. Sx Schema di una pressa meccanica ad eccentrico. Dx Cinematismo Biella-Manovella
cinematismo. La pressa meccanica utilizzata nel processo industriale analizzato ha le seguenti caratteristiche cinematiche: Raggio di manovella = 100 mm, Velocità di rotazione = 55 rpm, Rapporto (raggio di manovella)/(Lunghezza di biella) = 0.14285. L’organo mobile con un moto alternativo esercita una forza sul materiale da deformare, durante la sua corsa attiva fino al Punto Morto Inferiore. In tale punto di lavoro la forza disponibile tende all’infinito, ma i costruttori limitano con dispositivi di protezione, la forza massima esprimibile in deformazione ad un valore detto nominale. La forza richiesta dal processo di deformazione deve essere sempre inferiore a quella disponibile. La prima deformazione è in gergo una tipica ricalcatura dello spezzone per discagliatura successiva al riscaldamento in forno ed un miglior posizionamento all’interno della sagoma della stazione di deformazione successiva. La billetta deformata viene collocata sullo stampo inferiore di Abbozzatura, in modo da poter coprire il più possibile il vuoto ricavato nello stampo, e quindi la figura da dover ottenere. In questa seconda fase, al contrario di quella di Ricalcatura in cui gli stampi sono piani, il materiale deve riempire il vuoto fra gli stampi, e quindi deve scorrere sulla loro superficie sotto l’azione della Pressa Meccanica che impartisce il cinematismo. La fase di Abbozzatura presenta un posizionamento della billetta ricalcata che non è univoco, infatti non sono state predisposte sullo Stampo Inferiore delle staffe di appoggio e trattenimento della billetta deformata proveniente dalla fase di Ricalcatura. E’ stata fatta la scelta di posizionare la billetta in modo che la superficie superiore coincidesse con la fine della superficie cava dello stampo inferiore, il robot antropomorfo ha un errore trascurabile nella determinazione di tale posizione. A fine deformazione l’abbozzato ha una forma moto simile a quella del prodotto finito, ma, in questa fase di deformazione, naturalmente, non viene richiesto né un riempimento ottimale né l’assenza di difetti, quali ripieghe. L’abbozzato viene tolto dalla cavità degli stampi tramite l’ausilio di un apposito estrattore, il manipolatore lo posiziona nella cavità dello stampo finitore; avendo una forma molto simile la figura riesce ad auto centrarsi per gravità nella posizione corretta desiderata. Sotto l’azione della stessa Pressa Meccanica, il manufatto viene portato a dimensioni nominali di progetto, il fi-
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nito rispetta la condizione di completo riempimento degli stampi, non presenta difetti nelle parti in cui non possono essere tollerati nella qualità di produzione ed ha un’altezza di bava pari a 5 mm. Il finito di stampaggio verrà successivamente sottoposto al processo di eliminazione della bava, sempre in linea quindi a caldo, trattamento termico, pulitura superficiale, coniatura e controllo prima di essere inviato alle macchine utensili per le lavorazioni per asportazione di truciolo. Sebbene il processo non presenta difetti di stampaggio, si nota prima di tutto che il materiale iniziale utilizzato per lo spezzone di billetta potrebbe essere minimizzato, visto il peso rilevante occupato dalla bava; secondariamente, in ordine di tempo ma non di importanza, si evidenzia come dopo un numero di cicli esiguo per una larga produzione di serie si arrivi alla rottura degli stampi. Studio di Processo attraverso Analisi FEM Lo studio del processo reale è stato condotto attraverso codice numerico che permettesse dapprima di poter definire tutti i parametri di processo e poi poterne studiare, secondo la loro variazione, le influenze nel processo stesso. E’ stato implementato l’intero ciclo di stampaggio partendo dalla billetta fredda dimensionata secondo progetto reale ed il suo inserimento in forno, fino alla completa deformazione in fase di Finitura; nel Codice Numerico è stato implemento un chaining delle varie fasi di stampaggio, in modo da poter automaticamente far calcolare l’intera sequenza e seguire in essa l’evoluzione del comportamento del materiale in deformazione, con particolare attenzione alla termica del processo, alle tensioni ed alle sollecitazioni. La modellazione del processo nelle sue diverse fasi prevede non solo quella geometrica, di facile implementazione con i moderni CAD, ma anche quella fisica, in cui il materiale, la termica ed i contatti rivestono ruoli primari. Il materiale della parte deformabile è descritto tramite il modello di Hansel Spittel (Fig.4), mentre gli stampi in ogni fase di stampaggio sono considerati come elementi indeformabili, infinitamente rigidi ed a temperatura costante (temperatura a regime). Lo scambio termico è definito in modo da descrivere il fenomeno sia quando la billetta è a contatto con gli stampi (αT = 2.0e+04 W/m²°K; effus = 1.176362e+04), sia quando non lo è e quindi scambia calore con l’ambiente circostante (αText = 10.0e+00 mW/mm/°C); per la velocità di esecuzione di proces-
Fig. 4 - Coefficienti del modello di Hansel Spittel del C25/ 1.0406
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36 - Newsletter EnginSoft Year 9 n°4 so di deformazione alla pressa meccanica, ci si aspetta che l’influenza dello scambio termico sia di bassa rilevanza tra i diversi parametri in gioco. Attraverso la Legge di Coulomb-Tresca, l’attrito è stato definito in maniera conforme alla realtà dei diversi setup delle fasi di processo reale; in fase di abbozzatura non viene interposto alcun lubrificante, mentre le fasi successive di abbozzatura e finitura hanno una lubrifica spinta per poter far scorrere il materia- Fig. 6 - Lo stampo superiore, nella fase di finitura, presenta rottura dopo un numero esiguo di le in deformazione nelle parti vuote dello stampate, rispetto alla totale produzione, concentrata in una determinata zona ben visibile. Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC. stampo. E’ stato quindi implementato un coefficiente alto di attrito in fase di abbozzatura (m = 0.6; µ = 0.3) stampo in fase di finitura (quello che nella realtà subiva la rote più basso in fase di abbozzatura e finitura (m = 0.1; µ= 0.05) tura dopo un esiguo numero di cicli di stampaggio). A tale scorispettando l’omogeneità di distribuzione dei lubrificanti che po si è adottato un modello dello Stampo di Finitura deformabinella realtà è ottenuta in maniera automatizzata. le, sia elasticamente che elasto-plasticamente, ed è stato calcoTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la lato il grado di sollecitazione e deformazione elasto-plastica traperfetta implementazione cinematica del manovellismo della mite la proiezione su di esso delle forze ricavate dal modello a pressa meccanica precedentemente descritto. Tra una fase di stampi rigidi. Dall’analisi delle sollecitazioni dello stampo dustampaggio e quella successiva è stato implementato il calcorante la fase di finitura si evidenzia, nella parte finale di deforlo della caduta termica in aria per un tempo necessario alla mazione, la concentrazione di elevati valori della tensione prinmovimentazione reale della billetta, ottenendo quindi una cipale (1srPrincipalStressTensor) in quella che nella realtà appamappa della temperatura più adiacente alle condizioni reali di re come la linea di innesco della frattura (Fig.6); se positivo, il stampaggio. 1srPrincipalStressTensor rappresenta il massimo sforzo di trazione, ed il superamento di valori critici è il primo fattore di rottuTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la ra fragile. I valori pur non superando quelli critici hanno caratperfetta implementazione cinematica del manovellismo della tere ciclico, per cui la fenomenologia da indagare è quella di rotpressa meccanica precedentemente descritto. Tra una fase di tura per fatica oligociclica. stampaggio e quella successiva è stato implementato il calcoLo stampo superiore, nella fase di finitura, presenta rottura dolo della caduta termica in aria per un tempo necessario alla po un numero esiguo di stampate, rispetto alla totale produziomovimentazione reale della billetta, ottenendo quindi una ne, concentrata in una determinata zona ben visibile. Il materiamappa della temperatura più adiacente alle condizioni reali di le stampo è X37CrMoV5 H11 bonificato 42 HRC. stampaggio. I risultati ottenuti dal calcolo FEM, sono stati confrontati con quelli reali di stampaggio validando la scelta dei nuFenomeno di Rottura per Fatica Oligociclica merosi parametri di processo assunti nelle varie fasi. La forma fiLo studio condotto ha permesso di legare la fatica ai fenomeni nale dello stampato, la sua mappa termica e le forze di stampagdi micro-deformazioni plastiche cicliche locali indotte dal ciclo gio calcolate sono identiche a quelle ottenute nella realtà, così di sollecitazioni, il cui valore di sforzo localmente può superare come i difetti di ripieghe sono collocati negli stessi punti, cioè il carico di snervamento anche se il carico macroscopico esterno in bava e nelle zone di lavorazione meccanica successiva. rimane sempre al di sotto di esso. Il danneggiamento per fatica Tale studio preliminare condotto ha avuto l’obiettivo di modelprocede attraverso un primo assestamento microstrutturale, che lare le condizioni reali di processo, fino a poter valutare il grastabilizza il ciclo di isteresi plastica dello stampo metallico e, di do di sollecitazione degli stampi durante il processo deformaticonseguenza, stabilizza alcune caratteristiche meccaniche e fisivo. Gli stampi, come precedentemente affermato, sono stati asche dello stesso. Si generano microintagli dovuti a slittamenti sunti come infinitamente rigidi ed indeformabili, per cui la se'disordinati' dei piani cristallini del metallo che nella successiconda fase di studio, partendo dai risultati validati, ha valutato, va fase di nucleazione andranno a costituire l'innesco del dancon approccio disaccoppiato, lo stato di sollecitazione dello neggiamento per fatica. Gli sforzi risultano amplificati per effetto d'intaglio cosicché facilmente il materiale in quel punto cede e si formano delle microcricche. Queste tendono a riunirsi andando a formare la cricca vera e propria, che si considera ormai nucleata quando raggiunge la profondità di circa 0,1 mm. Dopo la nucleazione della cricca, la sua propagazione avviene in maniera fragile e in senso perpendicolare a quello del massimo sforzo. L'avanzare della cricca porta ad una progressiva diminuzione di sezione resistente: quando questa diventa inferiore alla Fig. 5 - Risultati delle simulazioni di stampaggio
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sezione critica, si ha la frattura finale di schianto per sovraccarico (statico). La resistenza a fatica degli stampi è frutto della combinazione di stress meccanici e termici, in Fig.7 è rappresentata qualitativamente la metodologia di Valutazione composita delle componenti meccaniche e termiche della deformazione, ciò ha permesso di stimare la vita utile dello stampo studiandone la sollecitazione ed i suoi effetti di fatica (Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC). Al fine di valutare eventuali variazioni termiche sullo stampo, sono state analizzate le temperature della billetta in corrispondenza della zona maggiormente sollecitata ed i fattori metallur- Fig. 7 - Valutazione composita delle componenti meccaniche e termiche della deformazione gici di influenza Il limite di fatica si lega inevitabilmente: Con algoritmi di tipo MAES (Meta-model Assisted Evolution • alla tensione di rottura Rm ed ai fattori che la modificano; Strategies MAES) si utilizza una valutazione delle minimizzazio• fattori meccanici legati all'esercizio e al dimensionamento ni e dei vincoli per selezionare gli individui che si vogliono efdel prodotto metallico; fettivamente calcolare. Ci sono differenti tecniche per costruir• la finitura superficiale e la corrosione. lo e il tempo di valutazione usando il Meta Model varia in funzione della tecnica scelta ma in tutti i casi esso è molto più breAnche la forma del pezzo ha importanza sulla vita a fatica, ogni ve della semplice analisi FEM ed è quindi possibile incrementalieve variazione di sezione, determinando delle concentrazioni di re la dimensione della popolazione mantenendo il tempo per tensioni e localizzando le deformazioni, agisce sempre nel senl’ottimizzazione pressoché costante. so di una netta diminuzione del limite di fatica, per questo hanno un'azione dannosa fori, intagli e spigoli vivi. Ottimizzazione di Processo Lo studio di lavorazione per deformazione fin qui descritto è stato propedeutico alla ricerca del miglior setup per l’individuazione dell’ottimo binomio prodotto/processo ed all’analisi avanzata dell’influenza dei vari parametri. Si è proposto quindi l’impiego di un approccio statistico da correlare alla fase di raccolta dati che permettesse alla progettazione di raggiungere i seguenti risultati: • riduzione dei tempi di sviluppo dei processi; • uso più efficiente delle risorse; • maggiore affidabilità dei processi. Nell'ambiente industriale la complessità dei fenomeni impedisce il pieno controllo dei fattori sotto indagine e una conoscenza teorica completa: ciò significa che non sempre è nota a priori la relazione di causa-effetto tra i fattori che influiscono sul processo in esame e le variabili da ottimizzare, una delle tecniche di progettazione per massimizzare le informazioni derivanti da dati sperimentali è il Design of Experiments (DOE), metodo che consta di due fasi principali: • fase di screening: identificazione dei fattori significativi e loro correlazione; • fase di ottimizzazione: identificazione della risposta. La scelta dell’algoritmo nel codice numerico utilizzato è di tipo generico: • iniziare da una popolazione: un numero predefinito di individui che può essere definito prima generazione; • valutarli (calcolarli e valutare minimizzazioni e vincoli); • selezionare i migliori, riprodurli e creare una nuova generazione.
Fig. 8 - Scelta casuale della popolazione iniziale rispetto al numero dei parametri
Tali algoritmi presentano la limitazione di richiedere diverse centinaia di valutazioni e di simulazioni complete; la Strategia di Evoluzione Assistita da Meta-Model (MAES) rende possibile ridurre considerevolmente il numero dei calcoli effettivi. Si possono ottenere buoni risultati all’interno di poche decine di calcoli e grazie al calcolo parallelo, le analisi/simulazioni possono essere condotte allo stesso tempo riducendo il tempo di ottimizzazione. Gli algoritmi evolutivi (ES) consistono tipicamente di tre operazioni: selezione, ricombinazione e mutazione, per ridurre il numero di valutazione di funzioni. Lo studio di ottimizzazione condotto sul processo deformativo preso in considerazione può essere riassunto nella scelta dei target della funzione Obiettivo da minimizzare, parametri di variazione e vincoli da rispettare: Target Obiettivo di ottimizzazione • Minimizzazione volume iniziale billetta. • Minimizzazione carico pressa durante la fase di abbozzatura. • Minimizzazione carico pressa durante la fase di finitura. Vincoli di ottimizzazione • Completo riempimento stampi in fase di finitura. • Assenza di difetti di stampaggio in fase di finitura.
Case Histories
38 - Newsletter EnginSoft Year 9 n°4 Analizzando non solo i setup efficaci, ma l’intera popolazione di parametri scelti nei ranges di interesse, si sono valutate le influenze che la variazione di parametri scelti hanno sul carico degli stampi in fase di abbozzatura e soprattutto di finitura, visto che questa è la fase in cui la rottura degli stampi avviene dopo un numero esiguo di cicli di stampaggio. Fig. 9 - Intera popolazione di individui di ottimizzazione. La variazione di massa della billetta iniziale riflette una variabilità estremamente accentuata della forza di stampaggio nella fase di abbozzatura, mentre nella fase di finitura, così come ci si aspetta dalla configurazione della fase di stampaggio, presenta una più modesta minimizzazione. Il grafico di Fig.9 riporta la totalità dei casi analizzati. Nel grafico di Fig.10 si riporta l’andamento Fig. 10 - Individui che soddisfano i vincoli della forza di stampaggio in funzione della massa iniziale di billetta, solo per i 21 casi (su 40) soddisfacenti il vincolo di completo riempimento e nessuna ripiega in finitura, si evidenzia come la ricerca dell’ottimo, pur spaziando su tutto il range, si concentra nella zona di minimo carico e minimo volume. Nel grafico di Fig.11 si riporta l’andamento della forza di stampaggio in funzione del posizionamento della billetta in fase di abbozzatura rispetto alla posizione originaria. Si nota Fig. 11 - Influenza della variazione di posizione della billetta in fase di abbozzatura sulla forza di stampaggio nella fase di abbozzatura e sulla fase di finitura. Individui che soddisfano i vincoli come la forza di stampaggio risulta essere non correlabile alla variabile posizionamento, infatti la billetta ricalcata posizionata sullo stampo inferiore di Parametri di ottimizzazione abbozzatura tende sempre a “scivolare” verso la parete di ap• Lunghezza billetta = min 94% lunghezza originale, corripoggio perdendo la variazione di posizionamento. I risultati dispondente a una riduzione massima di peso di 2 kg. mostrano come la convergenza dell’algoritmo MAES porti ad una • Posizionamento billetta: traslazione massima 15,5 mm lungo soluzione soddisfacente in cui il vincolo di riempimento è sodasse X (Xg = -2mm). disfatto dopo la prima generazione dell’algoritmo, e le generazioni successive permettono di minimizzare l’acciaio impiegato L’algoritmo MAES è stato organizzato con una popolazione di 10 e di minimizzare la forza impiegata nelle fasi di Abbozzatura in famiglie di 4 individui ciascuna, per un totale di 40 casi di commaniera significativa e di Finitura in misura minore (Fig12). In binazioni. Ogni combinazione prevede lo sviluppo di tutto il proquesta fase gli stampi accolgono tutto l’abbozzato andando a cesso di forgiatura e quindi le varie fasi di Ricalcatura, contatto con lo stesso direttamente sulla bava, il materiale in Posizionamento billetta ricalcata nella fase di Abbozzatura, deformazione è costretto a riempire, ma non può fluire verso Abbozzatura e Finitura, per un totale di 160 simulazioni complel’esterno. Le cavità degli stampi sono già completamente riemte di forgiatura. pite quando al cinematismo mancano ancora 3,5 mm di corsa, durante la quale il carico della pressa non aumenta, vista la suRisultati perficie ormai tutta in presa, bensì aumentano gli sforzi di traL’interfaccia grafica di visualizzazione dei risultati del codice zione massima sugli stampi nella sezione in cui si innesca la numerico utilizzato è estremamente intuitiva, attraverso rancricca. Tale ultimo risultato, unitamente alla deformazione e king dei diversi casi, permette di valutare immediatamente la riempimento visualizzabile step by step, ha posto le basi di imsoluzione migliore. Il ranking viene organizzato in maniera auplementazione di ottimizzazione successiva: partendo dalla sotomatica mediante una funzione di costo, che valuta il rispetto luzione migliore di prima ipotesi ed indagando un range di vadei vincoli inseriti ed il risultato ottenuto in termini di miniriazione del volume iniziale della billeta che minimizzasse ultemizzazioni richieste. Analizzando i numerevoli risultati prodotriormente il risultato ottenuto, ed aggiungendo ad essi una difti, automaticamente si riesce a distinguere, in verde, i setup che ferente geometria del preformato di Abbozzatura. hanno rispettato i vincoli di processo imposti, cioè il completo La nuova fase di abbozzatura studiata prevede un prodotto pririempimento e l’assenza di difetti nei volumi ove ciò è richievo di bava, la forma è molto meno vicina al finito di stampagsto, dalle soluzioni in arancione in cui le impostazioni non sogio, quindi più intermedia. Questa soluzione registra una noteno sufficienti a soddisfare tali vincoli.
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Newsletter EnginSoft Year 9 n°4 -
vole diminuzione del carico pressa in fase di Abbozzatura, ma anche in fase di Finitura. La modifica al processo, dopo l’analisi di ottimizzazione e le valutazioni delle influenze dei parametri, ha permesso una distribuzione più omogenea degli sforzi e delle deformazioni nelle diverse fasi di processo, studiando una preformatura che permettesse di utilizzare ancor meno materiale (Fig.13), garantendo un completo riempimento ed assenza di difetti nel prodotto finale. Per minimizzare il rischio di rottura duttile nello stampo di finitura è stato accentuato il raggio di raccordo nel punto di innesco (R1) per non favorire la concentrazione localizzata degli sforzi di trazione, gli altri parametri geometrici (R2 ed L1) non sono significativi, così come la temperatura iniziale (T1) dello stampo perché bassa, mentre è da monitorare la temperatura finale (T2) perché ad un suo aumento corrisponde una maggiore deformabilità del materiale fino a valori critici.
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Fig. 12 - a) Diverso posizionamento in fase di Abbozzatura. b) Contatti e riempimento in Finitura del Caso Iniz. e del Caso Ott. c) Carico in Abbozzatura per il Caso Iniz. e per il Caso Ott. d) Carico in Finitura per il Caso Iniz. e per il Caso Ott.
Conclusioni Lo studio condotto sul processo di stampaggio a caldo di acciaio si è incentrato su un’analisi numerico sperimentale, i cui obiettivi principali sono stati l’ottimizzazione del processo prendendo in esame le variazioni dei parametri nei range di analisi; tale approccio ha consentito di dare rigore a quelle soluzioni nel processo in esame che discendevano dalla Fig. 13 - Influenza dei parametri geometrici dello stampo su resistenza a Fatica Termo Meccanica. semplice esperienza degli operatori ed ha con- Risparmio di materiale dopo due studi di ottimizzazione di processo. sentito l’ottimizzazione del ciclo di produzione di un componente di geometria complessa. La modellazione numerica, analizzando i fattori più influenti, ha L’ottimizzazione multi-obiettivo è stata condotta sull’intero prodato l’opportunità di proporre ulteriore minimizzazione del macesso ed i risultati hanno permesso di correlare i principali pateriale e suggerire variazioni delle geometrie degli stampi al firametri di processo ai benefici desiderati ed ottenuti: risparmio ne di avere un prodotto che in fase di finitura richieda una midi materiale (benefit economico) e diminuzione di onerosità di nore drasticità di applicazione del carico pressa, intimamente processo (benefit energetico-economico-ecologico): collegato al fenomeno di rottura degli stampi in quella • Ottimizzazione del materiale: faseL’ottima rispondenza nel confronto numerico sperimentale • -27% di risparmio di materiale scartato dopo Prima ha consentito di desumere l’affidabilità dei risultati forniti, il Ottimizzazione che potrà portare alla possibilità di migliorare cicli già esisten• -49% di risparmio di materiale scartato ti, ma anche di progettare nuovi componenti e cicli di produziodopo Seconda Ottimizzazione ne con vantaggi in termini di tempo ed economici. La sperimen• Ottimizzazione del carico pressa pari a: tazione virtuale non è più considerata come una fase di test vol• 1399 T fase di abbozzatura: - 24 % dopo Prima ta a verificare se l'implementazione pratica di un nuovo procesOttimizzazione so/prodotto risponde effettivamente agli obiettivi fissati in fa• 1200 T fase di abbozzatura: - 31,4 % dopo se di progettazione. Essa apporta valore aggiunto se pensata Seconda Ottimizzazione non solo come conferma di quanto previsto ma soprattutto co• 1500 T fase di finitura: - 4,2 % dopo Prima me potenziale fonte di opportunità di miglioramenti non intuiOttimizzazione bili a priori. • 1400 T fase di abbozzatura: - 10,4 % dopo A.Pallara - EnginSoft, Seconda Ottimizzazione Y.Cogo, S. Mazzoleni - Feat Group • Assenza di difetti e di ripieghe nella soluzione ottimizzata. Per ulteriori informazioni: • Completo riempimento in fase di finitura della soluzione Marcello Gabrielli, EnginSoft ottimizzata. [email protected]
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40 - Newsletter EnginSoft Year 9 n°4
Nella International CAE Conference si è tenuto il Meeting Italiano degli utilizzatori di Forge Il 23 ottobre, all'interno della International CAE Conference, il centro di competenza simulazione di processo - forgiatura di Enginsoft ha voluto invitare tutti gli utilizzatori del software Forge/ColdForm per una sessione di aggiornamento sui prodotti. Transvalor, la casa produttrice del software, ha voluto essere presente con il dott. Jean Fourniols e l'ing. Laetitia Pegie, che hanno illustrato la roadmap di sviluppo dei prodotti e suggerito il 'modus operandi' di utilizzo. L'incontro, al quale hanno assisitito una quarantina di persone, ha visto protagonisti anche alcuni utenti, che hanno presentato il proprio lavoro: l'ing. Sartori di Muraro-Stipaf (nella foto) ha raccontato come intere linee di laminazione circolare vengono progettate in virtuale, tenendo conto di tutte le fasi e della metallurgia del materiale, l'ing. Pallara di Enginsoft ha mostrato un caso pratico di ottimizzazione di una forcella in acciaio stampata a caldo da FEAT
Group, il dott. Michele Francesco Novella del DII - Università di Padova ha mostrato come è possibile prevedere l'evento di frattura duttile nello stampaggio a freddo ed infine l'ing Inaki Perez di Tecnalia ha illustrato come nei laboratori spagnoli si utilizzano questi strumenti per simulare il complesso processo di rotary forging. I partecipanti hanno potuto apprendere informazioni utili per l'uso quotidiano di Forge e ColdForm, ma soprattutto conoscersi e scambiarsi consigli su come far rendere al meglio questi strumenti. Il centro di competenza di Enginsoft sulla forgiatura (in foto da sinistra a destra l'ing. Andrea Pallara, l'ing. Marcello Gabrielli e l'ing. Federico Fracasso) ha nelle pause approfondito tematiche individuali, con il supporto di Transvalor. Appuntamento per tutti all'edizione numero 10 dell'Italian Forge Users' Meeting, nel 2013. Per ulteriori informazioni: Marcello Gabrielli, EnginSoft [email protected]
Events
EnginSoft al Convegno AIM di Trento Dal 7 al 9 novembre si è svolto a Trento il 34° Convegno Nazionale di A.I.M. (Associazione Italiana Metallurgia), che ha visto la partecipazione di oltre 300 persone provenienti sia dal mondo universitario e della ricerca, che dal mondo industriale. Enginsoft ha voluto essere presente a questo importante evento in una duplice veste, come sponsor e portando dei contributi scientifici nelle sessioni tecniche. E' stato quindi allestito uno stand, dove si sono alternati Marcello Gabrielli, Piero Parona e Giampietro Scarpa, che hanno dato informazioni in merito alle diverse attività di simulazione e di ottimizzazione che Enginsoft è in grado di affrontare. Per le sessioni tecniche, Marcello Gabrielli ha presentato nella sessione Acciaieria un lavoro di ottimizzazione condotto in collaborazione con FEAT Group dal titolo 'Studio di fattibilità produttiva attraverso simulazione numerica', mentre Giampietro Scarpa ha illustrato nella sessione Pressocolata, che ha visto come chairman Piero Parona (Presidente del Centro di Studi Pressocolata di AIM) il lavoro 'Analisi delle difettologie nel processo di pressocolata: contributo della simulazione numerica'.
Enginsoft è stata invitata a tenere una lezione al Corso di 'Siderurgia e fonderia' del 5° anno Corso di Laurea Magistrale in Ingegneria dei Materiali. Il 20 novembre l'ing. Marcello Gabrielli è stato invitato dal prof. Giovanni Staffelini a tenere una lezione agli studenti del 5° anno di Laurea Magistrale dell'Università di Trento - Facoltà di Ingegneria del Materali. La lezione ha riguardato una panoramica dei processi di solidificazione in lingottiera e di colata continua, affrontati dal punto di vista della simulazione numerica. Il docente ha illustrato quanto sia difficile definire un materiale per questo tipo di simulazioni, per poter ottenere dei risultati prossimi alla realtà produttiva. La presentazione di alcuni casi reali ha stimolato la discussione in aula e l'interesse dei ragazzi, che hanno visto applicate nella pratica le nozioni apprese durante il loro percorso di studi. Sono emersi anche alcuni temi di interesse, che saranno approfonditi in prossimi lavori di tesi, nei quali la simulazione potrà avere un ruolo importante.
Newsletter EnginSoft Year 9 n°4 -
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Multidisciplinary optimization for a IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform INTRODUCTION TO THE RUBEECOMP PROJECT THE OBJECTIVES RuBeeCOMP is a research project co-funded by the Regione Toscana (Italy) in the frame of the POR CReO funding program.
which were installed into the vehicle as illustrated in the concept picture in Figure 1, enable these measurements. The main objective of the RuBeeCOMP project is to define the best possible configuration for the composite structure and the wireless tag. For the specific work and the required data, a numerical platform was developed that coordinates both, the geometrical/functional parameters of the tag and the composite laminate. The technological platform was developed in order to integrate the data obtained during the project’s preliminary phases and from the parametric FE models, to achieve the best configuration for the executive design.
Fig. 1 - Simulation of a submarine mission for the inspection of the seabed
The aim of the project is to study, test and assess materials, systems, technologies as well as design methodologies for the manufacturing of composite material components. Wireless communication systems able to operate in radiofrequency unfriendly environments, such as oil or water, are also included in the study and project activities. At first, the composite demonstrator with the wireless communication system has been installed into a submarine vehicle, which is able to explore the seabed and to monitor the submarine environment by performing optical and sound surveys, and physical and chemical analyses. Suitable sensors
Fig. 2 - 3-point-bending test realized on composite virgin and aged specimens
Fig. 3 - Environment tests on composite specimens containing the wireless tag (a) and electromagnetic setup of the communication systems (b)
Research & Technology Transfer
42 - Newsletter EnginSoft Year 9 n°4 The five main Project “Work Packages” completed during the last two years allow to define the optimum solution for the technological demonstrator realized, guaranteeing the highest achievable level of performances in terms of structural and electromagnetic response.
Fig. 5 - Structural FE model developed in ANSYS Mechanical and ANSYS ACP environments
EXPERIMENTAL ANALYSIS Once the functional requirements of the wireless tag and the whole vehicle are defined on the base of mission length, depth and velocity expected and amount of information collected, a preliminary study of the vehicle geometry is carried out, of Fig. 6 – Draping and Flat Wrap analysis realized in ANSYS ACP on the rear double-curved surfaces the candidate wireless communication systems and of a set of candidate composite laminate, several full parametric models are realized using an materials through a rich experimental campaign. On the hybrid approach (numerical and empirical) verified within composite materials chosen, a set of physical and mechanical ANSYS Maxwell and ANSYS HFSS simulation environments. The tests are realized on virgin and aged specimens, with or main variables evaluated for the electromagnetic issue are without the wireless tag. magnetic field and inductance, functions used hereinafter in the optimization environment to select the best allowed configuration. The first model represents the prototype of an antenna with a 42mm radius multi-turn coil made of 33 loops of a copper wire (section radius equal to 0.25mm). The second model is a multi-turn printed loop on a 0.8mm thick FR4 laminate. The CPW fed antenna is made of 16 properly distanced 0.6mm wide microstrip copper line turns. The background scenario was modeled by imposing radiation boundaries to the problem region in order to simulate free emission into space. In the operational environment, the latter could be a lossy and/or conductive media like sea water Fig. 4 - Electromagnetic F models developed in ANSYS HFSS simulation or oil and it should be consequently modeled with the environment correspondent electric characteristics. To evaluate the established communication degree, two different multi-turn tags are tested: a 33-turn copper wire coil STRUCTURAL MODELS and a multi-turn microstrip coil. All the composite specimens The numerical platform developed for the RuBeeCOMP research are tested through thermal and moisture loads, structural project allows to maximize the structural and electromagnetic loads (time-increasing distributed pressure, bending), performances through suitable optimization tools, analyzing vibrations and shockproof, monitoring internal and external custom FE models built in ANSYS environment. The damages using an ultrasound waves control. The tests realized technological demonstrator’s geometry, containing the allow to make an accurate mechanical characterization of the wireless communication system, is defined during the first composite materials, analyzing the electromagnetic preliminary study on the base of the results obtained through performances of the multi-turn tags and the agreement fluid-dynamic analysis. Once the demonstrator’s geometry is between communication systems and composites as well. defined, it is imported and analyzed within the platform using the ANSYS code and in particular its ACP module - ANSYS ELECTROMAGNETIC MODELS Composite Prep/Post – which represents the most suitable tool to evaluate the whole composite structure’s performances. The The IEEE 1902.1 “RuBee” communication standard defines the ACP’s features allow to manage in an efficient and flexible way air interface for radiating transceiver radio tags using long all the pre and post-processing phases, evaluating the wavelength signals, up to 450 kHz. These devices have a very industrial feasibility according to the assumed production low power consumption (a few microwatts), they operate over process (ACP’s Draping & Flat wrap functions). Moreover, other medium ranges (0.5 to 30 meters) and at low data transfer specific features allow to verify damage conditions deriving speeds (300-9600 bps). To design and optimize the from in-plane and out-of-plane stress distributions, through communication systems dipped in a multi-layer composite
Research & Technology Transfer
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interface to build the laminate’s stacking sequence for each design during the optimization process. Through this interface the definition of the laminate layup is driven by a customized algorithm that allows to create a symmetric and balanced laminate, using practical engineering rules based on sublaminate approach, in order to guarantee an easy implementation from the production point of view. In this way the problems caused by technological effects are completely deleted, avoiding the need to insert any constraint after the definition of the composite layup within the optimization process.
Fig. 7 – Sub-laminate approach used by ESAComp-modeFRONTIER interface for the definition of the laminate’s stacking sequence for each optimization design
PLATFORM USER INTERFACE In order to create an accessible and easy-to-use technological platform and a comprehensible multidisciplinary design procedure, a Java language user interface is created through a customization focused on the logical procedure and on the specific electromagnetic and structural issues studied. When using the user interface, the designer does not need to edit the programming code manually; the code allows to manage automatically the numerical FE models, the input variables, the objective functions and the file transfers. Through the interface, the user can edit the ESAComp composite materials
customized multi-failure criteria, such as Max Stress, Max Strain, Tsai Wu, Tsai Hill, Puck 2D/3D, Hashin 2D/3D, LArC, Cuntze and so on. During the platform and user interface development, the debugging of the platform that implements the design procedure is realized using a simplified geometry in which the wireless system is contained. Once the main platform requirements are obtained in terms of effectiveness, efficiency and flexibility, its robustness and accuracy are evaluated analyzing the whole prototype structure. The technological platform allows to study the mechanical behavior of the submarine vehicle optimizing the performances, according with the objective functions related to structural stiffness and Fig. 9 – Analysis of results obtained through advanced post-processing tools in modeFRONTIER environment strength. EFFICIENT LAMINATE DEFINITION PROCEDURE One of the main results obtained during the development of the project is the processing and implementation of the ESAComp-modeFRONTIER interface within the technological platform. Within the design procedure, ESAComp fulfills the role of a library, in which the composite material data collected from the experimental campaign are contained. The material library is used by the ESAComp-modeFRONTIER
library, some geometrical and functional parameters of the wireless tag, the technological demonstrator’s geometry and the loads and constraints operating conditions. The platform allows to obtain the best solution maximizing or minimizing the objective functions linked with the structural performances considering several load cases at the same time.
Fig. 8 – User interface and modeFRONTIER workflow that manage the information and the variables of the numerical platform’s logical flow
MULTIOBJECTIVE AND MULTIDISCIPLINARY OPTIMIZATION Once all the main design parameters are defined by the interface, the numerical platform applies the implemented design procedure working independently. The information present in the material library are used to define for each design the laminate’s stacking sequence with the rules set in the ESACompmodeFRONTIER interface; the current composite laminate configuration is translated and exported for the next
Research & Technology Transfer
44 - Newsletter EnginSoft Year 9 n°4 realized, a final experimental campaign on the whole structure has been achieved to verify the quality of the electromagnetic signal within an unfriendly environment. The dissemination activities have brought a high visibility and prestige to the partial and final results obtained: the work progresses have been presented in dedicated sessions at the “International CAE Conferences” in 2009, 2010 and 2011. At this year's International Conference, the final results have been presented during the “Composite Session” where the presenters showed the technological demonstrator in a dedicated space within the ESAComp stand. Fig. 10 – Experimental tests realized on technological demonstrator in unfriendly environment
steps, represented by ANSYS HFSS (for the electromagnetic analysis) and ANSYS ACP (for the structural simulations). The numerical models built are solved and evaluated based on the strength of the objective functions’ values obtained, then available modeFRONTIER post-processing features allow to classify the results with multidimensional diagrams and charts. For the RuBeeCOMP research project, the postprocessing tools allow to evaluate the electromagnetic response of the multi-turn printed tag dipped in the fiber-
Fig. 11 – Exhibition of technological demonstrator at International CAE Conference 2012
reinforced composite laminate and the fiber-reinforced composite laminate and the structural performances of the technological demonstrator in several operating load conditions. In this case the objective functions are represented by the antenna inductance (L), magnetic field intensity (H), weight of the structure (W), displacements (D), Inverse Reserve Factor distribution (IRF). The information collected through the experimental campaign, preliminary design analyses and the results obtained through the platform, allow up to identify the best configuration to realize the executive design. CONCLUSIONS AND DISSEMINATION ACTIVITIES The RuBeeCOMP research project carried out during the last two years has enhanced the already robust relationship between EnginSoft, WASS and IDNOVA. The most important result is the production of the technological demonstrator, according to the executive design, containing the wireless communication system integrated within the composite demonstrator component. Once the demonstrator has been
Research & Technology Transfer
For more information: Fabio Rossetti, EnginSoft [email protected]
Meeting conclusivo del progetto 'RuBeeCOMP' Il Competence Center fiorentino di EnginSoft ha ospitato il ‘meeting’ conclusivo del progetto 'RuBeeCOMP' – attività di ricerca finanziata dalla Regione Toscana nelle modalità del programma POR CReO 2007-2013. Obiettivo principale della indagine tecnica è lo sviluppo di metodologie finalizzate alla progettazione integrata prodotto-processo per la realizzazione di componenti in materiale composito, caratterizzati da sistemi di comunicazione wireless; quest’ultimi sono concepiti al fine di operare correttamente in ambienti ostili alla radiofrequenza, come ad esempio l’acqua, l’olio, ecc. Il sistema RuBeeCOMP costituirà elemento principale di eccellenza dell’allestimento tecnologico della piattaforma AUV (Automonous Underwater Vehicle) denominata V-Fides Progetto di Ricerca al quale partecipa anche EnginSoft – e destinato alla gestione delle comunicazioni da e verso la piattaforma di lancio in acqua e/o a terra. Al sistema è infatti deputato l'onere di ricevere le informazioni dalla base, quindi la trasmissione alla stessa dei dati raccolti dal drone nel corso della missione subacquea finalizzata ad operazioni di detezione, esplorazione del fondale marino EnginSoft ha contribuito al progetto in modo poliedrico; lo sforzo tecnico spazia infatti dalla progettazione e simulazione dell’antenna di trasmissione/ricezione all’ottimizzazione del processo di produzione del supporto in materiale composito. All’incontro hanno partecipato tutti i partner che hanno collaborato allo studio e alla realizzazione del progetto: Whitehead Sistemi Subacquei (Wass), IDNova ed EnginSoft; inoltre alla riunione erano presente l’ing Vittorio Falcucci, attualmente Direttore tecnico di Eurotorp ma all’inizio dell'attività mentore e fortissimo sostenitore in Wass della liceità e delle prospettiche aspettative positive del progetto stesso e, il Professor Giuseppe Martini quale supervisore designato dalla Regione Toscana: tale ruolo, va detto, è stato interpretato in forma progressiva e stimolante, sicuramente percepibile nel corso dei meeting per la puntualità e la competenza dei chiarimenti tecnici richiesti.
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Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 La nuova release 14.5 di ANSYS Workbench, uscita a Novembre 2012, presenta numerose novità utili nella quotidianità delle applicazioni ingegneristiche. In particolare, analizzando l’ambiente Mechanical, si possono individuare diverse nuove funzionalità, sia per quanto riguarda la gestione della geometria, la generazione della mesh, la definizione dei contatti, che per quanto riguarda la soluzione vera e propria del problema e il post-processamento dei risultati. Si accenna qui alle più importanti novità rinviando i lettori interessati al servizio di assistenza tecnica EnginSoft per gli approfondimenti. Per quanto riguarda la geometria, è possibile ottenere in DesignModeler, modelli di più rapida gestione sia in fase di importazione che in fase di Fig. 1 - Gestione della geometria fino a 10 trasferimento a volte più rapida Simulation (velocità fino a 10 volte superiore per modelli di grandi dimensioni!). Questo è reso possibile dal fatto che la conversione a Parasolid non avviene più al momento dell’importazione dell’intero assieme come avveniva nelle release precedenti, ma solo al momento in cui si definiscano in DesignModeler delle modifiche alla geometria, e solo limitatamente alle zone interessate da tali modifiche (fig.1) Riguardo ai contatti, una “matrice dei contatti” configurabile consente una miglior comprensione delle connessioni tra le parti. Tale matrice è completamente personalizzabile e consente di gestire sia contatti veri e propri, che connessioni generiche quali spot weld, joint e spring. E’ possibile inoltre evidenziare i contatti presenti solo su un singolo corpo o su una named selection, in modo da facilitare la comprensione delle connessioni anche per assiemi complessi (fig.2).
Fig. 2 - Matrice dei contatti
Al fine di facilitare la leggibilità di modelli complessi, sono disponibili nella nuova release sia filtri basati sul nome dei componenti o delle named selections, sia la possibilità di utilizzare colori diversi in maniera random per plottare diverse condizioni di carico, vincolo, diverse named selection così da renderle facilmente identificabili (fig.3).
Fig. 3 - Colori random per il plottaggio di named selections
Per semplificare l’imposizione di condizioni al contorno o di carico simili, quasi tutti gli oggetti inseribili in Simulation possono essere riprodotti e copiati secondo diversi pattern, mantenendo però inalterati i dettagli dell’oggetto originario. E’possibile copiare in questo modo, per esempio, l’imposizione del medesimo precarico su un insieme di viti o ripetere gli
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46 - Newsletter EnginSoft Year 9 n°4
Fig. 4 - pattern di bolt pretension
stessi controlli di mesh su corpi simili (fig.4). Eseguire sub-model consente di risparmiare tempo quando si è interessati a ciò che accade in dettaglio su una porzione del modello. Oggi in WB è completamente implementata la procedura di sub-model per modelli 3D, in via completamente nativa. La rimappatura degli spoFig. 5 - Vantaggi derivanti dall’utilizzo della stamenti nelle zone di tecnologia GPU taglio non è eseguita con comandi APDL ma attraverso procedure interne a WB, e ciò consente di utilizzare le potenzialità di rimappatura già implementate per l’importazione di carichi ottenuti da solutori esterni (coefficienti convettivi, forze, temperature di bulk,..). Per quanto riguarda la fase di soluzione, il metodo “sparse solver” adesso può utilizzare GPU multiple al fine di ridurre il tempo di soluzione (fig.5). Per ridurre le dimensioni dei file dei risultati ottenuti durante il run, inoltre, la memorizzazione di essi viene effettuata a singola precisione per quanto riguarda le grandezze derivate, come le tensioni e le deformazioni (variabili di elemento). Per lo stesso motivo, le tensioni principali non vengono salvate nel file dei risultati, ma vengono rivalutate qualora se ne richieda il plot come quantità di post-process. In questo modo si riescono ad ottenere file di risultati fino al 50% più piccoli rispetto al passato. Per modelli con geometria ciclica, al fine di minimizzare lo spazio di memoria richiesto in fase di plottaggio, i risultati possono essere mostrati ed animati su una frazione di tutto il corpo simmetrico, scegliendo il numero di settori che si vogliono visualizzare. Spesso è utile inserire carichi o vincoli particolari, che possono essere presen-
Software Update
ti in numerose analisi che si vogliono impostare, come opzione dell’ambiente di simulazione. Nuovi carichi e condizioni al contorno possono essere aggiunti ad ANSYS- Mechanical tramite il nuovo modulo di personalizzazione ACT (per esempio condizioni al contorno acustiche). E’ possibile inoltre creare risultati personalizzati, come ad esempio il plot di criteri di massimo ammissibile basati su un rapporto di tensioni vs una proprietà del materiale, e inserirli nell’albero come un qualsiasi risultato standard. E’ possibile, sempre grazie ad ACT, utilizzare WB per lanciare solutori esterni o inserire add-on esterni nell’interfaccia Mechanical. E’ spesso necessario indagare, possibilmente in modo semplice, le conseguenze di cricche che compaiono in un componente a causa del processo di manifattura o a causa della fa-
Fig. 6 - effetto della presenza di una cricca in un sub-model
tica, al fine di evitare rotture premature dello stesso. Nella nuova release 14.5 cricche ellittiche possono essere inserite in geometrie nominali importate in WB, semplicemente definendo un centro di posizionamento associato ad un sistema di riferimento e le dimensioni della cricca che si vuole rappresentare. La mesh è quindi gestita automaticamente dal software senza la necessità di ulteriori azioni da parte dell’utente. I parametri di cricca (K1 per il modo 1, K2, K3, Stress intensity factor, Mixed mode J-integral, …) possono essere postprocessati e visualizzati lungo il path che segue il fronte della cricca, al fine di agevolare la comprensione dei risultati. Una cricca può essere introdotta anche all’interno di un submodel per ridurre il tempo computazionale totale e allo stesso tempo incrementare l’ accuratezza locale dei risultati ottenuti (fig.6). Si ricorda che è sempre possibile trovare informazioni relative alle novità inserite nella release 14.5 all’interno dell’help sotto la voce “Release Notes”. Per maggiori informazioni: Valentina Peselli - EnginSoft [email protected]
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Simulating Gear Pairs within SIMPACK
SIMPACK, a Multi-Body Simulation software tool, enables complete mechatronic systems which include high fidelity drivetrains to be accurately simulated. The individual forces acting between the gear wheel teeth can be easily visualized with force arrows and plotted. The SIMPACK Gear Pair element enables full three dimensional behavior such as dynamically changing angular and radial misalignments to be investigated. HISTORY Fig. 1 - Bevel gear with crowning Initially developed for Formula 1 high performance engines back in 2003 (by Lutz Mauer, an used for achieving the optimum balance between solver executive board member of SIMPACK AG), the SIMPACK speed and accuracy. For example, simple one-dimensional Gear Pair functionality has since been used in a large elements may be used for torsional analyses whereas variety of industrial sectors, e.g. automotive, wind, rail, gearbox elements (e.g. planetary gear stage) may be used shipping, aerospace, concrete mills, material handling, for more detailed analyses when reaction moments on the etc. housing are required. For simulations where individual tooth contact forces are required, the SIMPACK Gear Pair GENERAL force element, FE 225, may be used. This element enables the additional analyses of the meshing forces and In SIMPACK, a large variety of elements are available for moments, shaft bending, bearing forces, and a host of the simulation of torque converters. Depending upon the task at hand, elements of various level of detail may be other pertinent analyses (Fig. 2). Gear Pair FE 225 is an analytical element, and therefore, extremely fast simulation times can be achieved. Graphical primitives are defined for the gear wheels which are subsequently used for the force calculations. This results in accurate animation of the gear tooth contacts and play. The Gear Pair FE 225 includes the following: Gear Types: • Involute spur • Helical • Ring • Rack and Pinion • Bevel
Fig. 2 - Gear box with Gear Pair forces and other resultant forces
Input: • Profile Shift • Backlash
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48 - Newsletter EnginSoft Year 9 n°4 All modification types can be input for the right and left flanks or for both together.
Fig. 3 - Motion of floating sun within a planetary stage (© IMM, TU Dresden)
GEAR PAIR FORCE ELEMENT HIGHLIGHTS For simulating gear pairs with non-parallel axes, “slicing” of the gear wheel contact area is necessary. This is achieved by setting a single parameter (i.e. “Number of slices”) within the gear pair force element. The handling of the offset angles for helical gears is now fully automatic. Slicing is also necessary if flank modification is used. Shuttling forces, i.e. the axial displacement of the contact forces, is included. In the case of helical gears, this will result in an additional tilt moment. Users can easily switch on and off, and choose between, various output value types. This enables easier handling and a more efficient use of data storage space. The different types of output are described below. GEAR PAIR DATA CHECK In order to check the input parameters and initial conditions of the gear pairs within a model, a user can perform a “Test Call”. This will result in a list being generated for each gear pair consisting of important input parameters and calculated data. Information such as the theoretical center distance, radial offset, axial offset, transverse contact ratio, overlap ratio, and total contact ratio will now be readily available.
Fig. 4 - Bevel gear primitives
• Viscous and Coulombic damping • Tooth profile and flank modification. Simulated Behavior: • Meshing frequencies • Shuttling forces • Dynamically changing misalignments (radial and angular). GEAR PAIR PRIMITIVES For all gear pair types, tooth and flank modification is available. The modifications are primarily used for smoothing the non-linear internal excitations due to the continually changing number of teeth in contact. The following modification types have been added: • Tip (Fig. 5) • Root • Circular • Left and Right Side • Lead Crowning (Fig. 6) • Input Function Array
GEAR PAIR OUTPUT VALUES By way of parameterization, a user can choose for which gear pairs the “Basic Output Values” will be generated. These values include such data as the relative angles and angular velocities, “total normal contact stiffness” and the “dynamic transmission error”. Similarly, a user can also choose which “Advanced Output Values” are to be saved (Fig. 8). These values are primarily used for analyzing the coupling forces of the gear pairs, either for the sum of all teeth in contact or the individual tooth-pair contacts. In addition the “Advanced Fig. 5 - Tip profile modification Output Values” enable easy animation of the force arrows in the PostProcessor (Fig. 9). After an integration run is complete a user can subsequently choose which output values to generate. Re-running the time integration is not necessary. Only re-performing “measurements” is required.
Fig. 6 - Crowning, left and right flank
Software Update
CONCLUSION The SIMPACK Gear Pair Force Element is an important component in the analysis of drivetrains. Full three
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dimensional non-linear dynamic behavior can be investigated. Customer specific tooth profile and flank modification enables accurate simulation of meshing frequency excitations. Easy animation and plotting of contact forces accelerates comprehension of the dynamic non-linear behavior. Although major milestones in the development of the SIMPACK Gear Pair element have already been achieved, further development will continue to be implemented, enabling the Gear Pair to fulfill the even more demanding customer requirements of the future.
For more information: Fabiano Maggio, EnginSoft [email protected]
Fig. 7 - Rack and pinion gear
Fig. 8 - User choice for advanced output values
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TechNet Alliance Fall Meeting 2012 26th -27th October, Kassel - Germany The Fall Meeting of the TechNet Alliance, one of the world's largest networks of engineering solution providers, has taken place at the Schlosshotel Bad Wilhelmshöhe in Kassel on the last days of October. Apart from the many interesting lectures, the leading theme of the meeting was a full immersion into the HPC environment for technical computing. To update the audience from around the world on the latest developments in this area, three exciting presentations were delivered: 1. Herbert Güttler from MicroConsult provided a detailed history of HPC and a comparison chart which allowed the delegates to “travel” through the years, various versions and hardware of HPC and GPU performances in ANSYS. 2. Dejan Milojicic from Hewlett Packard spoke about his comparisons of different commercial cloud computing solutions for true HPC calculations in the engineering market. 3. Johannes Heydenreich, PhilonNet Engineering Solutions, presented his company’s experiences in setting up a remote cluster utilization at the University of Athens. Mr Güttler’s speech was an extremely deep analysis of multi GPU performances on single and multi-node clusters. It covered a very complex benchmark which was impressive in terms of its good scaling results in the thermo-elastic-plastic mechanical scenario. Already during the presentation, it became clear that it would be quite time consuming to carry on the work. Key points of the presentation where, among others, the speed performances of releases 14 and 14.5 on the new Intel platforms E5-26XX (due to compiler optimized code) and GPU/CPU scaling in both the PCG and Direct Matrix Solver. Dejan Milojicic presented a wide spectrum of benchmarks performed on commercial cloud computing services with respect to performances of multi-core scientific (chemical and number crunching) calculations. The findings were, as a professional user would expect, the following: - Commercial real HPC cloud computing can only be delivered by a limited number of providers - All web offers are only able to provide, in most cases, 4 cores and no real high speed interconnection. - True HPC for scientific computing has to be provided by specialized companies. Mr Heydenreich’s brief presentation was about the real use case of setting up a remote visualization for scientific computing at the University of Athens. He presented web components that have been chosen to deliver services to students and professors on a centralized cluster system for both calculation and visualization.
Fig. 9 - Animation arrows of normal loads “Indiv. load (fl_n) i,k”
For more information: Gino Perna, EnginSoft - [email protected]
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50 - Newsletter EnginSoft Year 9 n°4
ENGINSOFT coordinates the new “MUSIC” European Project
After a long procedure, the “MUSIC” project times, and shorter intervals between (the acronym stands for: “Multi-layer successive generations of products. control & cognitive System to drive a metal Therefore, MUSIC is strongly aimed at and plastic production line for Injected leading EU-HPDC/PIM factories, for a Components”) has finally received the cost-based competitive advantage positive approval of a technical and through the necessary transition to a scientific Committee. The decision-makers demand-driven industry with lower waste are responsible for selecting Collaborative generation, higher efficiency, robustness IP Projects in the FoF-ICT sector (Factory of and minimum energy consumptions. The Future and Information & Communication Fig. 1 - MUSIC PROJECT LOGO development and integration of a Technologies) applied to energy-aware, completely new ICT platform, based on agile manufacturing and customization. an innovative Control and Cognitive system linked to real time The core concept of the project focuses on the result of the monitoring, allows an active control of quality, avoiding analysis and the possible improvements that can be achieved defects or over cost by directly acting on the process-machine and applied to the two most representative large-scale variables optimization or equipment boundary conditions. The production-lines in the manufacturing field: High Pressure Die Intelligent Manufacturing Approach (IMA) works at machineCasting (HPDC) of light alloys and Plastic Injection Moulding mould project level to optimize the production line starting (PIM). Both are of strategic importance to the EU industry from the management of manufacturing information. An which is largely dominated by SMEs. Intelligent Sensor Network (ISN) monitors the real-time Due to the high number of process variables involved and the production acquiring the multi-layers data from different non-synchronization of the process control units, HPDC and devices and an extended meta-model correlates the input and PIM are most “defect-generating”. Moreover, “energy sensors data with the quality indexes, energy consumption consumption” processes in the EU industries provide less cost function. Data homogenization, centralization and flexibility to any changes in product and process evolution. synchronization are the key aspects of a control system to Owing to both of these factors, sustainability requires that collect information in a structured, modular and flexible machines/systems are able to efficiently and ecologically database. support the production with higher quality, faster delivery Process simulation, data management and meta-models are the key factors to generate an innovative Cognitive system to improve the manufacturing efficiency. The MUSIC project is an FP7 European project that introduces new ICT technologies at manufacturing plants with introduces significant potential impacts: (i) it can strengthen the global position of the European manufacturing industry; (ii) it can create a larger European market for advanced technologies such as electronic devices, control systems, new assistive automation and robots; (iii) it improves the intelligent management of manufacturing information for customization and environmental friendliness. The MUSIC project’s final target is the transformation of an extremely conventional manufacturing sector such as HPDC of light alloys and PIM of polymers into an Intelligent Manufacturing System, capable of zero-defect production, Fig. 2 - MUSIC core concept
Research and Technology Transfer
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Fig. 3 - MUSIC project structure in EUCOORD
energy saving and cost reduction. The achievement of this target passes through multi-level objectives, contributing to a knowledge-based and dynamic management of HPDC/PIM manufacturing data. The MUSIC Project started on September 1st, 2012 and will run for 4 years, under EnginSoft Coordination and Management, with more than 9 million Euros of costs, two thirds funded by the European Commission. MUSIC is a fully integrated project, since the Consortium is constituted by 16 complementary European members (ENGINSOFT SPA, ELECTRONICS GMBH, HOCHSCHULE AALEN, MAGMA GMBH, UNIVERSITA DEGLI STUDI DI PADOVA – DTG, FUNDACION TEKNIKER, FUNDACIO PRIVADA ASCAMM, OSKAR FRECH GMBH CO KG, TOOLCAST SNC, MAIER, S.Coop. AUDI AKTIENGESELLSCHAFT, RDS MOULDING TECHNOLOGY SPA, MOTUL SA, REGLOPLAS AG, FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V, ASSOMET SERVIZI S.R.L) which cover with their different activities and know-how, the entire value-chain, from RTD to demonstration, from prototyping to standardization, as described in the 8 work-packages into which the project is subdivided. For a more efficient and easy management of the project, EUCOORD is proving a very useful tool, since it is a web-based collaborative tool specifically designed for Project Management and Financial Accounting. It assists Coordinator and Partners in keeping the project on track, allowing project structure handling (details on Workpackages, Tasks, Milestones, Deliverables, in terms of technical content, leadership, duration and deadlines), correct data collection (partners information, profiles, contacts, detailed activities assignment with related resources), accounts management (inputs of costs and effort provided by partners are stored and validated by the coordinator), reports generation and disseminations planning, web-site creation, management and customization, including also a passwordprotected area for internal communication and document sharing, also of confidential nature. The starting point of the project was marked in Vicenza, on September 17th and 18th 2012, when the Kick-off Meeting took place. A group of 60 people representing the 16 partners engaged in the project, gathered at the University of Padova located in Vicenza, for a two-day meeting. The meeting content was articulated in three different sessions aiming respectively at:
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1. Analyzing the state of the art of the control for different devices in the production line. 2. Providing attendees with general information concerning management & coordination, communication strategies, project content and structure, partners’ interactions and contributions, responsibilities and duties in compliance with the contract and its annexes. 3. Presenting WP1 tasks and objective so to focus and structure the first RTD objectives to be discussed and performed. The activities performed by now are mainly concentrated in the technical and scientific tasks of WP1 and management (WP8) as well. First project dissemination activities have been promoted so to give visibility to project existence by presenting the public summary and objectives in two different international event, ALUMINUM 2012 (Düsseldorf Messe, 9-11 October 2012) and INTERNATIONAL CAE Conference (Lazise – Verona, 22-23 October 2012). As soon as first results and achievements will be available, further actions will be planned for targeted knowledge transfer and sharing. In this perspective the project has been submitted to NAFEMS World Congress of next year (Salzburg – June 2013). The MUSIC Project web site has been submitted to the European Commission on November
Fig. 4 - The kick-off meeting in Vicenza
15th, 2012. It describes the structure, contents and functionalities of the Project portal: http://music.eucoord.com/ and its connection with the EUCOORD platform for Project Management. This first meeting has been very successful, especially because all of the participants were enthusiastic to start the new challenge and at the same time could share with each other their cutting-edge technologies and knowledge. These exchanges among the partners are fundamental for a positive beginning of the project. The enthusiastic and promising assertiveness is essential for good and profitable results to move from “music” to “symphony” in manufacturing production lines! For more information: Nicola Gramegna, EnginSoft [email protected]
Research and Technology Transfer
52 - Newsletter EnginSoft Year 9 n°4
Modellazione e Progettazione Ottimale di Strutture Ceramiche Un progetto di ricerca e innovazione nell’ambito dei Partenariati e percorsi professionali industria-università Il gruppo di ricerca in Meccanica dei Solidi e delle Strutture del Dipartimento di Ingegneria Meccanica e Strutturale dell’Università di Trento coordina il progetto INTERCER2, finanziato dalla Comunità europea nell’ambito degli IAPP (Partenariati e percorsi professionali industria-università). Il gruppo di ricerca è guidato dai professori Davide Bigoni e Luca Deseri e include tra i suoi componenti il professor Massimiliano Gei e i ricercatori Francesco Dal Corso, Andrea Piccolroaz e Roberta Springhetti. Il progetto INTERCER2 mira ad un approfondimento della conoscenza scientifica del processo produttivo della ceramica, con il duplice scopo di ottimizzare la produzione e sviluppare nuove strategie tecnologiche ed industriali che consentano di ridurre i costi di progettazione e fabbricazione dei componenti ceramici, migliorandone contemporaneamente la prestazione e l’affidabilità. Gli obiettivi verranno raggiunti sia attraverso la modellazione della compattazione delle polveri e del processo produttivo sia mediante lo sviluppo di strutture e materiali ceramici multifunzionali avanzati.
L’industria ceramica è un settore ampiamente consolidato in Europa e le ceramiche avanzate sono cruciali nello sviluppo di nuove tecnologie, con applicazioni alla nanotecnologia; tuttavia la produzione industriale delle componenti ceramiche si basa ancora spesso su processi empirici, non sempre sufficientemente razionalizzati e difficilmente controllabili, con la conseguente generazione di quantità rilevanti di scarti e residui di produzione. Il progetto di ricerca è focalizzato sulla modellazione meccanica, implementazione numerica e simulazione dei processi produttivi, con particolare riguardo alla simulazione dei processi di formatura delle polveri ceramiche, dove il gruppo di Meccanica dei Solidi e delle Strutture ha già un’esperienza ben consolidata. Usando tecniche moderne basate sulla teoria dell’elastoplasticità si è infatti sviluppato un modello costitutivo che, tarato su prove meccaniche con protocollo preparato ad hoc, permette la simulazione di processi di formatura a freddo rendendo possibile la determinazione dello ‘spring-back’, delle distribuzioni di densità, stress residui e delle caratteristiche elastiche interne al pezzo a fine forma-
Fig. 1 - Grafici, da sinistra: distribuzioni di stress residuo, densità di vuoti e modulo di elasticità tangenziale nel componente ceramico a termine del processo di formatura. I risultati sono ottenuti da simulazioni numeriche in cui è implementato un modello costitutivo specifico per le polveri ceramiche compattate a freddo sviluppato dal gruppo di Meccanica dei Solidi e delle Strutture dell’Università di Trento.
Research and Technology Transfer
Newsletter EnginSoft Year 9 n°4 -
tura. Attraverso lo strumento su cui il gruppo di ricerca sta lavorando è possibile ottimizzare la forma dello stampo e la composizione delle polveri per ridurre lo scarto e ottenere pezzi di caratteristiche meccaniche ottimali. Più nel dettaglio, gli argomenti che saranno sviluppati nel progetto di ricerca sono i seguenti: Formatura di polveri ceramiche. Si svilupperanno strumenti per la modellazione e la simulazione del processo di formatura, basandosi su teorie costitutive innovative per la descrizione delle proprietà meccaniche dei materiali ceramici. Tali modelli saranno fondamentali per l’implementazione in codici numerici e la loro applicazione allo sviluppo di nuove e più efficienti tecnologie di produzione. Trattamento di composti ceramici. Una profonda comprensione dell’influenza dei parametri del materiale alla scala micrometrica all’interno del processo permetterà di raggiungere elevati standard di qualità nella produzione e sinterizzazione della ceramica. Miglioramento delle proprietà delle ceramiche. Si affronteranno problematiche legate alla meccanica della frattura ed alla caratterizzazione delle ceramiche e dei materiali compositi, impiegando in maniera duale l’approccio sperimentale e tecniche numeriche. In particolare si svilupperà una tecnica speciale per la simulazione delle proprietà ceramiche capace di descrivere i complicati processi di nucleazione del danno e di propagazione della frattura. I risultati numerici verranno verificati mediante varie tecniche a raggi x in-situ ed in laboratorio ricreando ambienti realistici. Modellazione di componenti meccaniche in presenza di difetti. Strutture ceramiche con difetti e interfacce imperfette, con enfasi sull’interazione fra incrinature e microstruttura, verranno analizzate mediante modellazione analitica e numerica. Nuove applicazioni tecnologiche per i materiali ceramici. L’obiettivo è la modellazione e progettazione di prodotti ceramici innovativi contenenti strati sottili d’interfaccia ed aventi proprietà multifunzionali. Il progetto è inoltre volto a stimolare la mobilità intersettoriale e a migliorare la condivisione delle conoscenze tra i partner del consorzio, in particolare mediante l’assunzione di ricercatori esperti, il distaccamento di personale dall’accademia al settore industriale e viceversa e l’organizzazione di conferenze internazionali, workshop e seminari. Il consorzio responsabile del progetto di ricerca, oltre all’Università di Trento, vede la partecipazione delle università britanniche di Liverpool e Aberystwyth e di due industrie. I partner industriali sono la EnginSoft, che si occupa degli aspetti computazionali della modellazione di componenti ceramiche, e la Sacmi, gruppo internazionale e leader mondiale nel settore delle macchine per la produzione di ceramici.
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Davide Bigoni e Luca Deseri Università di Trento Gruppo di ricerca in Meccanica dei Solidi e delle Strutture http://ssmg.unitn.it/ Sito del Progetto INTERCER2 http://intercer2.unitn.it/
EnginSoft ed il progetto INTERCER2 EnginSoft contribuirà al progetto collaborando con le Università e con Sacmi per lo sviluppo e l’implementazione di modelli di simulazione del processo di formatura del materiale ceramico. A partire da modelli esistenti in letteratura, che faranno da banco di prova, fino ad arrivare all’implementazione delle equazioni costitutive innovative per la descrizione delle proprietà meccaniche della ceramica che andranno declinate all’interno dello strumento FEM in relazione ai tipi di analisi richieste. Non solo, EnginSoft potrà contribuire anche alla caratterizzazione degli stessi materiali sulla base di dati sperimentali e utilizzando ove necessario tecniche DOE (Design of Experiment) per la definizione di un preciso piano di esperimenti siano essi fisici o virtuali atti a comprendere al meglio la sensibilità dei più significativi parametri di uscita rispetto a quelli di ingresso Una volta disponibili modelli rappresentativi del fenomeno sarà possibile anche implementare metodologie utilizzabili al livello industriale, ed atte alla ottimizzazione del processo di produzione delle ceramiche o parti di esso, processo che ha come fine ultimo lo sviluppo di prodotti ceramici innovativi. Il progetto pur operante sul piano della ricerca e difatto rilasciando indicazioni ingegneristiche di contenuto innovativo è già noto nelle problematiche ed in metodologia per effetto di recenti attività svolte dal team di EnginSoft Il contenuto delle attività di analisi è la realizzazione di una procedura numerica tale da consentire la determinazione della forma dello stampo di un semplice componente ceramico per ottenere una precisa geometria della ceramica a valle del processo produttivo di essicazione e cottura. Tuttavia lo studio è da intendersi come preliminare, in quanto le leggi che descrivono il comportamento del materiale in queste due fasi, sono ricavate da modelli semi-empirici noti in letteratura. Tali leggi potranno essere sostituite da modelli più accurati in eventuali fasi successive di analisi. In estrema sintesi lo studio si sviluppa sulla capacità di riprodurre una geometria in formato 3d in seguito ad una serie di analisi pilotate autonomamente ed automaticamente dal software e a partire da una popolazione di forma iniziali fino ad arrivare alla forma ottima in grado cioè di ridurre al minimo la differenza tra la forma finale ottenuta numericamente e quella obiettivo desiderio del marketing. Per ulteriori informazioni: Francesco Franchini, EnginSoft [email protected]
Research and Technology Transfer
54 - Newsletter EnginSoft Year 9 n°4
Corsi di Addestramento Software 2013 L'attività di formazione rappresenta da sempre uno dei principali obiettivi di EnginSoft. Per ciascuno dei possibili livelli cui la richiesta di formazione può porsi (quella del progettista, dello specialista o del responsabile di progettazione), EnginSoft mette a disposizione la propria esperienza per accelerare i tempi del completo apprendimento degli strumenti necessari con una gamma completa di corsi differenziati sia per livello (di base o specialistico), che per profilo professionale dei destinatari (progettisti, neofiti od analisti esperti). La finalità è sempre di tipo pratico: condurre rapidamente all'utilizzo corretto del codice, sviluppando nell'utente la capacità di gestire analisi complesse attraverso l'uso consapevole del codice di calcolo. Per questo motivo ogni corso è diviso in sessioni dedicate alla presentazione degli argomenti teorici alternate a sessioni 'hands on', in cui i partecipanti sono invitati ad utilizzare attivamente il codice di calcolo eseguendo applicazioni guidate od abbozzando, con i suggerimenti del trainer, soluzioni per i problemi di proprio interesse e discutendone impostazioni e risultati. Anche per il 2013 EnginSoft propone una serie completa di corsi che coprono le necessità di formazione all'uso dei diversi software commercializzati. Le novità proposte, confermano che l’idea che EnginSoft ha della formazione non è una realtà statica che si ripropone uguale a se stessa di anno in anno, ma è un divenire, guidato dall'esperienza accumulata negli anni, dall'evoluzione del software e dalle esigenze delle società che si affidano a noi per la formazione del proprio personale. In tale contesto EnginSoft organizza e sviluppa anche attività didattiche attraverso un programma formativo personalizzato, soluzioni di progettati in relazione alle necessità e alle specifiche esigenze aziendali del committente.
Training
In particolare, l’offerta dei corsi ANSYS viene ridefinita ogni anno per adeguarsi, sia all’evoluzione del software ed alle caratteristiche dell’ultima versione disponibile, che all’introduzione di nuovi moduli e solutori. In tale senso si segnala: • in campo fluidodinamico-strutturale l'introduzione, accanto ai corsi tradizionalmente erogati, del corso ANSYS CFX - MECHANICAL: Corso Interazione FluidoStruttura. • in campo fluidodinamico l'introduzione del corso ANSYS CFD: Corso Avanzato di Aeroacustica. Sono stati inoltre rivisti ed aggiornati i corsi relativi a tutti gli altri software sostenuti da EnginSoft per adeguarli allo stato attuale delle relative distribuzioni. In particolare per quanto riguarda SCILAB si evidenzia l’introduzione di un nuovo corso: • SCILAB-03-IT: Introduzione a Xcos e Modelica. Dal punto di vista organizzativo nel 2013 tutte le sei sedi EnginSoft saranno impegnate nella formazione, dando la possibilità agli utenti di scegliere la location a loro più conveniente in termini di vicinanza geografica alla propria società. Tutto questo a riprova dell'impegno nella formazione che, per EnginSoft, è e rimane un punto fondamentale della politica aziendale, un impegno costante verso l'eccellenza, un servizio per fare crescere i suoi clienti e, se lo desiderano, crescere con loro.
www.enginsoft.it/formazione Segreteria organizzativa: [email protected]
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© 2012 NVIDIA Corporation. All rights reserved. NVIDIA, the NVIDIA logo, NVIDIA Quadro, Tesla, and CUDA are trademarks and/ or registered trademarks of NVIDIA Corporation. All company and product names are trademarks or registered trademarks of the respective owners with which they are associated.
56 - Newsletter EnginSoft Year 9 n°4
International CAE Conference: like never before! More than 700 people from all over Europe attended the 28th edition of the International CAE Conference. Special guest Professor Parviz Moin, from Stanford (USA), presented innovation algorithms aimed to simulate large scale CFDs models. The edition 2012 of the “International CAE Conference”, was held October 22nd and 23rd, at the Hotel Parchi del Garda in Lazise, Verona – Italy. More than 700 people coming from all over the world and representing the fields of research, academic and the companies operating in the sector attend the Italian landmark event in the world of simulation technology and CAE (Computer Aided Engineering). Dozens of international companies and institutions engaged in the event, hardware vendors (HP, IBM) and CAE solution’s providers: EnginSoft, ANSYS, EESTECO, Mentor Graphics, Lms , AVL, SCSK and many others. Special guest, during the morning section, was Professor Parviz Moin, founder and director of the Centre for Turbulence Research at Stanford University (California). An initiative created in 1987 as a research consortium
between NASA and Stanford University and is dedicated to the study of turbulent motions; it concerns many different areas of our daily lives: from aviation to wind energy, from medicine to biology. Professor Moin has pioneered the use of Large Eddy Simulation, which is a particular methodology for the simulation of turbulence and a reference point in the sector. The conference opened with a letter by Giorgio Squinzi, President of Italian Industrial Association – CONFINDUSTRIA - who, despite his absence, wanted to express his good wishes. Squinzi highlighted the need on the part of companies 'to roll up their sleeves and tackle contingencies, without losing sight of the competitive environment in the medium term,' stressing that 'the issues addressed in the CAE Conference are undoubtedly exceptional competitive levers for the development of better products and reduced operational costs and times'.
Fig. 1 - Prof. Parviz Moin, University of Stanford, special guest of the 2012 CAE Conference
Events
Professor Moin, in his speech, emphasized the role played by simulation in terms of business and investment as well as in occupation. 'Simulation is important because it improves efficiency for companies and decreases costs he explained. Virtual testing today is used not only to validate laboratory experiments but mainly to make new discoveries, in addition, of course, to the work of designing new products. Simulations are more accurate; in particular the carrying out of the design phase has improved 20 thousand times since the origins. “Where is simulation used? As Moin explains, it
Newsletter EnginSoft Year 9 n°4 -
Fig. 2 - The Plenary Session
is an advanced technology that touches all sectors: from the design of aircraft turbines to the analysis of pollution, passing through automotive cooling systems. 'Virtual simulation can become an opportunity for employment for young people: 'Industry is adopting simulation in the process of design and production, so there are great opportunities for work - concluded Professor Moin. But it is essential to focus on a type of education that has a solid foundation in calculus, physics, and computer science'. Among the leading companies present at the event, is EnginSoft, a world leader in innovation consulting, testing and virtual CAE, as well as being a sponsor of the conference. Stefano Odorizzi, President and Founder of EnginSoft, highlighted, in his speech, that simulation has grown over the years and he especially emphasized the large number of areas where it can be applied.'Through numerical simulation it is possible to reproduce the behaviour of a particular subject in a potentially infinite number of diverse situations. From mechanics to fluid dynamics, from acoustics to the biomedical sector, simulation allows great strides forward, as it accurately reproduces reality. We have learned that networking is the key to promoting innovation, because each sector has something to offer in terms of know-how. By joining forces we can get better results'. Simulation has positive repercussions in the biomedical field, as testified by Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Remuzzi presented the research project for 'validation of computational models for surgical planning of vascular access in
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haemodialysis patients'. Currently there are about 2 million people worldwide suffering from end-stage renal disease, a condition that in most cases requires haemodialysis. As explained by Remuzzi, currently the leading cause of morbidity and hospitalization in haemodialysis patients consists of the short and long-term dysfunction in the vascular access used to connect the patient's bloodstream to the artificial kidney. 'Through this project - said Eng. Remuzzi – computational tools have been developed with the specific aim of preventing complications during surgery'. The next step will be to validate this study on the clinical front, in order to be able to understand the effectiveness, functionality and impact of this new tool that could pave the way for other simulation applications in the biomedical field. For more information: [email protected] www.caeconference.com
Fig. 3 - Attendees at the Technical Sessions
Fig. 4 - Attendees at the Exhibition Area
Events
58 - Newsletter EnginSoft Year 9 n°4
CAE Poster Award: A reward to the genius of young researchers As part of the CAE Conference, a prize has been awarded to the top six innovative ideas in the field of simulation. Amongst the winners: The University of Padua, the Mario Negri Institute and the Polytechnic of Milan. The CAE Poster Award is an award for the genius, the commitment and the resourcefulness of young people, researchers and businesses. Among this year's winning posters are: an innovative motorcycle helmet, a project that simulates the restructuring of the Arena of Verona, a method for the treatment of heart disease, new solutions in the automotive field. This award demonstrates that simulation can be a real opportunity for young people, in their exchange of ideas with companies and institutions, to reach new frontiers in occupation and employment. The Poster Award is a project promoted and sponsored by EnginSoft, a world leader in innovation consulting, with the aim of promoting and spreading the culture of simulation and of rewarding the quality of new developments by young researchers. Six of them have been rewarded for their innovative ideas in the use of virtual simulation technology. The competition was divided into two categories: Industry (for companies) and Academy (for universities) and saw the participation of more than 50 students and businesses from all over Italy and Europe. An initial selection of the 10 best posters in each category was made by a Scientific Committee, who later announced the three winners for the Industry and three students for the Academy section, who won a Tablet PC each. The event, hosted by Luca Viscardi, of Radio NumerOne, was attended by Stefano Odorizzi, president and founder of
Events
EnginSoft, and Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Odorizzi said that he was pleased with the competition: 'The Poster Awards were a success. Many projects were submitted, much beyond our expectations. Through this undertaking we wanted to create an opportunity for interaction between the business world and the universities.' Over 50 projects were presented, 31 of which reached the final stage. They are mostly posters created by young students from Italian universities, particularly from those of Padua, Salento, Basilicata and Ferrara, from the Milan and Turin Polytechnics, from the Universities of Bologna, Cassino and Pisa. One of the projects comes from the Mario Negri Institute, while, amongst the companies, we note Mox-Off, Pierburg Pump Technology and LyondellBasell. Eng. Remuzzi, representing the Mario Negri Institute, stressed the important role that virtual simulation can have in the biomedical sector, 'Biomedicine needs these new technologies to test new and different techniques, in order to achieve important results'. As for the students, the winners were: • Davide Bertini, from the University of Padua; Mr Bertini submitted a poster on the simulation of renovation of complex historical buildings, such as the Arena of Verona;
Newsletter EnginSoft Year 9 n°4 -
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• Matteo Longoni of Mox-off; Mr Longoni implemented a project to simulate the comfort of a motorcycle helmet while aiming at reducing time and costs associated with the design phase; • Marco Stevanella, from Polytechnic of Milan; Mr Stevanella presented a study to detect and quantify aortic malformations, which affect about 2 percent of the European population. Amongst the companies and the research community, the winners were: • Massimo Nutini, who submitted a poster on the characterization of plastic reinforced with glass fibre, widely used in most industrial productions. Nutini works for LyondellBasell, the third largest independent chemical company in the world; • Lorenzo Botti, from the Mario Negri Institute, presented a study, on an open source software platform, concerning a system that simulates blood circulation; • Giorgio Peroni of Pierburg Pump Technology presented a poster on the vacuum pump, for automotive applications. For more information: EnginSoft Marketing Department [email protected]
EnginSoft sostiene le attività di Ricerca dell'Istituto Mario Negri di Milano Venerdì 30 Novembre Stefano Odorizzi, ha visitato la sede di Milano - Bicocca dell’Istituto Mario Negri per rinnovare la collaborazione tra EnginSoft e la Fondazione iniziata in occasione dell’International CAE Conference 2012. Silvio Garattini, fondatore e Direttore dell’istituto di ricerche farmacologiche, ha accompagnato il CEO di EnginSoft in una vista ai laboratori e agli strumenti in dotazione alle centinai di ricercatori che si adoperano quotidianamente nella comprensione degli intimi meccanismi di funzionamento degli organismi viventi ed individuare le ragioni per cui insorgono le varie malattie in seguito all'introduzione di sostanze estranee. Nel corso dell’incontro Odorizzi ha consegnato al Professor Garattini un contributo di destinato ad alimentare le attività della Fondazione. “Ringrazio EnginSoft, e la sensibilità dell’ingegner Odorizzi, per l’attenzione dimostrata al lavoro svolto dell’Istituto – ha dichiarato Silvio Garattini -. Il sostegno profuso da Aziende e privati cittadini è un pilastro fondamentale e strategico sul qual poggia il Mario Negri. Questa generosità consente a tutti noi di combattere, da oltre 50 anni, la quotidiana battaglia contro le malattie dell’uomo”. “EnginSoft sostiene da sempre la Ricerca e le iniziative atte a valorizzare il capitale intellettuale dei giovani ricercatori e riteniamo questa collaborazione con il Mario Negri un ottimo modo per farlo – afferma Stefano Odorizzi -. Ringraziamo il
Professor Silvio Garattini per averci dato questa preziosa opportunità e ci auguriamo che ci siano altri importanti progetti per unire le nostre forze”. L'Istituto di Ricerche Farmacologiche Mario Negri è un'organizzazione scientifica che opera nel campo della ricerca biomedica. È stato costituito giuridicamente nel 1961 e ha iniziato le attività nella sede di Milano il 1° febbraio 1963. L’impegno della fondazione guidata da Silvio Garattini si articola, oltre che sulla Ricerca Farmacologica, anche nell’Informazione e Formazione. Infatti l'Istituto svolge anche attività di insegnamento per la formazione professionale di tecnici di laboratorio e ricercatori laureati e contribuisce, con molteplici iniziative, alla diffusione della cultura scientifica in campo biomedico: sia in senso generale che a specifico sostegno della pratica sanitaria per un uso più razionale dei farmaci. Tutti possono contribuire a sostengo delle attività dell’Istituto Mario Negri. I contributi che Enti e Privati Cittadini offrono all'Istituto di Ricerche Farmacologiche Mario Negri sotto forma di liberalità, donazioni e lasciti ereditari sono devoluti a incrementare i programmi di ricerca per lo studio delle più gravi malattie che affliggono l'uomo e a istituire borse di studio per i giovani ricercatori cui saranno affidate le ricerche future. Dettagli sulle attività di Ricerca, e come sostenerle con un contributo tangibile, possono essere consultate sul sito web dell’Istituto: www.marionegri.it
Events
CAE Poster Award 2012: Winners
Dipartimento di Costruzioni e Trasporti
Introduction The simultaneous need to preserve historic heritage and to appreciate its seismic vulnerability requires the development of techniques and methods used to properly establish the structural behaviour of historical monuments .
Method
resulting from non-destructive diagnostic tests, carried out on the masonry structures of the building, which allow to detect the real mechanical behaviour without loss of their functionality and efficiency.
Steps of the work The work has required the completion of the following basic steps:
x creation of a Finite Element Model complete in terms of structural geometry, loads, constraints and material properties;
x recovery of data from experimental studies previously carried out in significant positions of the monument;
x calibration of the model on the basis of the results of tests in situ.
Assumptions The starting hypothesis on which is based the development of the entire modeling is the use of materials with a linear elastic constitutive law . This assumption is generally recommended especially for qualitative analysis designed to asses the structural behaviour of a complex building.
Simulation and experimental validation The Finite Element Model of the whole building was refined and calibrated on the basis of data from experimental investigations carried out on the so-called 'Ala' ,
t vibration modes, it was obtained a significant correspondence between simulation
what is left of external ring after destructive past earthquakes.
and experimental results which has allowed to judge the correctness of the dynamic
In 1996 were realized some tests to determine its structural behaviour in relation to
behaviour of the Finite Element Model.
dynamic stresses: the acquisition of the signals was made with four accelerometers placed in pre-selected points of the structure. The Frequency Response Function obtained represents the deformability of each point of the structure to vary the excitation frequency. Modal shapes resulting from dynamic simulation applied to the Finite Element Model
[m]
Mode 01
Mode 02
Mode 03
Frequency 1,68 Hz
Frequency 2,42 Hz
Frequency 4,91 Hz
Mode 04
Mode 05
Mode 06
Frequency 5,89 Hz
Frequency 6,20 Hz
Frequency 7,18 Hz
P03 P01
Experimental Frequency Response Function for control points P01 and P03
P04 P02
1.4E-04 1.2E-04 1.0E-04 8.0E-05 6.0E-05 4.0E-05 2.0E-05 0.0E+00 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
[Hz]
Findings The modeling has been conducted assuming a linear elastic behaviour of all materials. This approximation has proved to be very useful to develop a model sufficiently accurate, avoiding the complications introduced by the use of non-linear diagrams. The validity of elastic modeling is demonstrated by the fact that the starting model, without corrections for adaptation to experimental values, has directly provided results very close to reality.
Future developments The study could be further developed taking into consideration the real constitutive laws of materials and the localized phenomena of deterioration which may affect the structural behaviour of the building.
CAE Poster Award 2012: Winners A multiphysic approach to improve helmets comfort and reduce time and costs in design process Longoni Matteo1, Formaggia Luca2, Ferrandi Paolo1 1
Moxoff Srl, Via D’Ovidio 3, 20131 Milano, Italy 2 MOX - Modeling and Scientific Computing Dipartimento di Matematica “F. Brioschi”, Politecnico di Milano, Italy Motivation
Goal
Improve helmet comfort in every-day conditions Key issue: pleasure of driving and safety
Develop a support design tool for engineers Simulate helmet performances efficiently
Technology
Starting point: very latest research works Handling of real and complex CAD geometries Model coupling: aerodynamics 3D, thermofluid 2D and vibroacustics 3D Multiphase (water/vapour) flows in porous media (comfort tissue/human hair) Human head sweating model for heat generation Advanced numerical methods Improvement and development of robust simulation codes Mathematical model
Vibroacoustic model - WIP!
ThermoFluid dynamic problem Navier–Stokes coupled with Darcy–Forchheimer: Penalized NS 0003 0002 ρCF μ (ρ(u · ∇)u − μΔu) χΩf + ∇p + u + √ |u|u χΩp = 0 k k ∂T + Cf u · ∇T = ∇ · (λp ∇T ) − le s(h, w , T ) Temperature T : ∂t ∂h Humidity h: + u · ∇h = Dh Δh + s(h, T , w ) ∂t ∂w Sweat content w : = ∇ · (Dw ∇w ) − s(h, T , w ) ∂t 0004 Mv Evaporation rate s: s(h, T , w ) = E (psat (T ) − pv (h, T )) χw + 2πRT
Ωf ,p ,w = fluid , porous, wet domain ρ = air density u = flow velocity t = time μ = dynamic viscosity p = pressure k = permeability Dh = water diffusivity χ = indicator function Cf , λp , le = thermodynamics Mv , R, psat , pv = psychrometrics CF , Dw , E = coefficients
Elastodynamics equations: ⎧ ρ∂tt u − ∇ · σ(u) = f, in Ω × [0, T ] ⎪ ⎪ ⎪ ⎪ on ΓD × [0, T ] ⎪ u = 0, ⎪ ⎨ σ(u) · n = t, on ΓN × [0, T ] on ΓNR × [0, T ] ⎪ non-reflecting b.c., ⎪ ⎪ ⎪ in Ω × {0} ⎪ ∂ t u = u1 , ⎪ ⎩ in Ω × {0} u = u0 ,
u = displacement t = time n = unit normal σ = stress tensor u0,1 = initial conditions f = external force Ω = 3D domain Γ = boundaries
Discontinuous Galerkin formulation Space–Time formulation Multi-domain formulation 3D hexa mesh
Multiphysic approach
0002
0002
Results
Accurate and efficient simulations of the physics involved Evaluation tool for engineers to explore different design solutions Time and costs of the overall design process drastically improved Optimized process satisfying comfort requirements for a successful product.
References P.F.Antonietti et al., “Non-conforming high order approximations of the elastodynamics equation”, CMAME, 2012. C.Canuto and F.Cimolin, “A sweating model for the internal ventilation of a motorcycle helmet”, Computers & Fluids, 2011.
M.Longoni, L.Formaggia, P.Ferrandi Moxoff, MOX
09/2012
A multiphysic approach to improve helmets comfort
CAE Poster Award 2012: Winners ZZZ0011ELRPHFK0011SROLPL0011LW0003
Healthy and BAV-affected aortic root dynamics: Fluid-Structure Interaction simulations from MRI-based 3D models M. Stevanella1, F. Sturla1,2, C.A. Conti1, E. Votta1, A. Della Corte3, A. Redaelli1 1 Department of Bioengineering, Politecnico di Milano, Milan, Italy Division of Cardiovascular Surgery, Università degli Studi di Verona, Verona, Italy Department of Cardiothoracic and Respiratory Sciences, Seconda Università di Napoli, Naples, Italy 2
3
Results and Discussion
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Year 8 n° 4 Winter 2011
Multi-objective Optimization with modeFRONTIER Applied to Systems Biology
EnginSoft CAE Conference 2011 Welcomes an Audience of 600 CAE users EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca
Synergy between LS-DYNA and modeFRONTIER to Predict Low Velocity Impact Damage on a Composite Plate
Structural Optimization of a Car-body High Speed Train An Innovative Analysis and Design Methodology
Electromagnetic issues for a IEEE 1902.1 “RuBee” tag dipped in a fiber/composite laminate
FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis
Newsletter EnginSoft Year 8 n°4 -
3
EnginSoft Flash CIRA, the Italian Aerospace Research Centre, For many of us, December is a time for illustrates the Synergy between LS-DYNA and reflection, for harvesting the fruit of our modeFRONTIER to predict low velocity work and our personal efforts of the year. impact damage on a composite plate. We Our Simulation and CAE environments hear from EnginSoft Nordic in Sweden on almost constantly see new developments, how multi-objective optimization is being upcoming software releases and changes. applied to systems biology. Here, we We are asked to be always ready for the encourage our readers to watch the movie “new”. While this is sometimes a challenge “Insulin Signaling (SignalPathways)” via the for most of us, every year also brings many link provided! new human encounters. In our fields of business, we can consider ourselves lucky We are pleased to introduce our customer to have the opportunity to meet people and ANSYS user the company Almacis, and from the CAE community, from around the AMD, our partner in the area of High world. While we learn about new and Ing. Stefano Odorizzi Performance Computing. different technologies, the human, the EnginSoft CEO and President Digimat is a powerful software for material engineer, its broad knowledge and modeling which is now distributed in Italy by experiences, always remain at the core of EnginSoft. More software news covers the LIONsolver by our attention. Reactive Research, NVIDIA’s Tesla GPU, EnginSoft’s By sharing our knowledge, especially on occasions such as activities for composite materials with ESAComp and the EnginSoft International Conference, we help to shape ANSYS Composite Prep/Post as well as MAGMA’s release the future path of CAE and to support the next generation 5.2. The powerful Sculptor tool allows users to of CAE engineers. parameterize any mesh based on arbitrary cubic bezier In this Newsletter, we speak about the EnginSoft and control points. Sculptor was recently presented by ANSYS Italian Conferences 2011, the two annual events EnginSoft GmbH at the ANSYS Conference and 29th that offer one of the major knowledge platforms to CAE CADFEM Users’ Meeting in Stuttgart. users in Europe and beyond. ANSYS is the provider of the world’s leading software for engineering simulation and Furthermore, we hear about Gruppo Ferroli’s project with EnginSoft’s number 1 partner. EnginSoft and ANSYS were EnginSoft, the recent introduction of the BENIMPACT delighted to welcome 600 delegates to Verona on 20th project in China and about the Minimaster and the and 21st October, to a wealth of topics on today’s use of Training Programs of TCN and EnginSoft. simulation and design tools. Our Japan Column tells us about the CAE University while In this issue, we also inform our readers about the Round some of the activities of JANCAE, The Japan Association Table Meeting of 100 Top Managers on the occasion of the for Nonlinear CAE, are explained to us in the article by opening of EnginSoft’s Research Center in the Scientific Hideo Takizawa. Technology Park ”Kilometro Rosso”. The use of ANSYS Please mark your diary for the modeFRONTIER Users' Maxwell v.14 is shown in the article on electromagnetic Meeting 2012, which will be sponsored by ESTECO and issues for a IEEE 1902.1 “RuBee” tag dipped in a take place on 21st and 22nd of May 2012 in Trieste. fiber/composite laminate. The capabilities of We hope that you enjoy reading the articles on the modeFRONTIER are described in AnsaldoBreda’s work for following pages of this last Newsletter of 2011. We always the structural optimization of a car-body high speed train. welcome your thoughts, your feedback as well as your Our readers also hear about the use of ANSYS AQWA and ideas for future publications! the ANSYS Workbench platform for the structural verification of the FSO Mooring System complemented by EnginSoft and the Editorial Team wish you and your EnginSoft’s broad experiences as a partner to the Oil&Gas families a very happy, healthy and a prosperous New Year industries. 2012! The Università degli Studi di Ferrara presents their work with ANSYS CFX 13.0 while University of Debrecen Hungary Stefano Odorizzi informs us of how Grapheur can help its users with multiple criteria decision- making problems. Editor in chief
4 - Newsletter EnginSoft Year 8 n°4
Sommario - Contents EVENTS
6 8 10
EnginSoft CAE Conference 2011: 600 partecipanti all’annuale appuntamento EnginSoft CAE Conference 2011 welcomes an audience of 600 CAE users EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca
CASE STUDIES
12 15 18 19 20 23 26 29
Electromagnetic Issues for a IEEE 1902.1 “RuBee” Tag Dipped in a Fiber/Composite Laminate Structural Optimization of a Car-body High Speed Train - An Innovative Analysis and Design Methodology FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis Finalized to the Structural Verification of the FSO Mooring System FEM analysis in Oil&Gas Industry Numerical Analysis of a Micro Gas Turbine Combustor Fed by Liquid Fuel Reconsidering the Multiple Criteria Decision Making Problems of Construction Workers Using Grapheur Synergy between LS-DYNA and modeFRONTIER to Predict Low Velocity Impact Damage on Composite Plate Multi-objective Optimization with modeFRONTIER Applied to Systems Biology
TESTIMONIAL
31
Eccellenza tecnologica e qualità: Almacis
SOFTWARE/HARDWARE NEWS
32 33 34 36 37
CAE Simulations and Innovations within the High Performance Computing HPC DIGIMAT per la modellazione avanzata dei materiali LIONsolver: Learning and Intelligent Optimization GPU Accelerated Engineering with ANSYS EnginSoft continua l’attività sui materiali compositi
EVENTS
38 39 39 40
EnginSoft presenterà la release 5.2 di MAGMA a METEF 2012 La simulazione di processo nella progettazione di radiatori modeFRONTIER Users’ Meeting 2012 EnginSoft GmbH Silver Sponsor at the ANSYS Conference & 29th CADFEM Users’ Meeting 2011
The EnginSoft Newsletter editions contain references to the following products which are trademarks or registered trademarks of their respective owners: ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. [ICEM CFD is a trademark used by ANSYS, Inc. under license]. (www.ansys.com) modeFRONTIER is a trademark of ESTECO srl (www.esteco.com) Flowmaster is a registered trademark of The Flowmaster Group BV in the USA and Korea. (www.flowmaster.com) MAGMASOFT is a trademark of MAGMA GmbH. (www.magmasoft.de)
ESAComp is a trademark of Componeering Inc. (www.componeering.com) Forge and Coldform are trademarks of Transvalor S.A. (www.transvalor.com) AdvantEdge is a trademark of Third Wave Systems (www.thirdwavesys.com)
.
LS-DYNA is a trademark of Livermore Software Technology Corporation. (www.lstc.com) SCULPTOR is a trademark of Optimal Solutions Software, LLC (www.optimalsolutions.us) Grapheur is a product of Reactive Search SrL, a partner of EnginSoft (www.grapheur.com) For more information, please contact the Editorial Team
Newsletter EnginSoft Year 8 n°4 -
RESEARCH AND TECHNOLOGY TRANSFER
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BENIMPACT Suite has landed in China
TRAINING
43
Alta formazione: TCN punta ad una specializzazione sempre più avanzata
JAPAN CAE COLUMN
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CAE Seminars in Japan “CAE UNIVERSITY” NPO Activity for Implementation of Anisotropic Elasto-plastic Models into Commercial FEM Codes
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Newsletter EnginSoft Year 8 n°4 -Winter 2011 To receive a free copy of the next EnginSoft Newsletters, please contact our Marketing office at: [email protected] All pictures are protected by copyright. Any reproduction of these pictures in any media and by any means is forbidden unless written authorization by EnginSoft has been obtained beforehand. ©Copyright EnginSoft Newsletter.
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PAGE 8: ENGINSOFT CAE CONFERENCE 2011 WELCOMES AN AUDIENCE OF 600 CAE USERS
PAGE 12: ELECTROMAGNETIC ISSUES FOR A IEEE 1902.1 “RUBEE” TAG DIPPED IN A FIBER COMPOSITE LAMINATE
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ASSOCIATION INTERESTS
PAGE 15: STRUCTURAL OPTIMIZATION OF A CAR-BODY HIGH SPEED TRAIN AN INNOVATIVE ANALYSIS AND DESIGN METHODOLOGY
NAFEMS International www.nafems.it www.nafems.org TechNet Alliance www.technet-alliance.com RESPONSIBLE DIRECTOR Stefano Odorizzi - [email protected] PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA
Autorizzazione del Tribunale di Trento n° 1353 RS di data 2/4/2008
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6 - Newsletter EnginSoft Year 8 n°4
EnginSoft CAE Conference 2011: 600 partecipanti all’annuale appuntamento La Fiera di Verona ha ospitato l’edizione 2011 del maggiore appuntamento in Italia dedicato al calcolo scientifico: l’EnginSoft International Conference, CAE Technologies for Industry e l’ANSYS Italian Conference. Oltre 600 i congressisti, esperti ed opinion leader in metodi e tecnologie CAE, che il 20 e 21 Ottobre scorso si sono incontrati, presso il Centro Conferenze del polo fieristico di Verona. Molte le aziende presenti, tra cui: Ansaldo, Piaggio, Magneti Marelli, Avio, Tetra Pak, Ferrari, Iveco, ENI, a dimostrazione dell’utilizzo crescente del CAE in ambito industriale. Tra gli obiettivi della Conference vi è stato quello di offrire ai partecipanti una visione d’insieme del comparto, attraverso il contributo di esponenti del mondo dell'industria, dell'università e della ricerca e dai numerosi sviluppatori di tecnologie intervenuti. “La Conference – ha spiegato Stefano Odorizzi, CEO di EnginSoft – è nata nel 1984 quando le tecnologie in fatto di sperimentazione virtuale erano solo oggetto di ricerca da parte delle università. Convinti che queste tecnologie avrebbero avuto un’evoluzione importante, abbiamo deciso di abbracciare la sfida e oggi continuiamo a perseguire l’obiettivo di trasferire agli operatori del settore le informazioni e le conoscenze relative a questi ambienti di simulazione e supporto alla progettazione”. Dopo la sessione plenaria di apertura che, oltre alla “Vision” da parte del Vice Presidente di ANSYS Inc., ha ospitato un mini simposio dedicato alla tematica del geo-modeling, l’evento è continuato su sessioni parallele, ognuna delle quali
Fig. 2 - Scorcio della sala conferenze di Verona nel corso di uno dei workshop.
Fig. 1 - Stefano Odorizzi - CEO di EnginSoft - in sessione plenaria.
focalizzata su una macroarea tecnologica o applicativa: meccanica, fluidodinamica, ottimizzazione, simulazione di processo, compositi, ecc. Di grande appeal sui partecipanti e di interesse perchè d’attualità, l’esperienza presentata da Ansaldo Energia di Genova in tema High Performance Computing. Stefano Santucci, IT manager di Ansaldo, ha illustrato le ragioni della migrazione da una struttura formata da sole workstation ad un cluster in cui l’hardware distribuito e HPC non solo convivono felicemente ma si integrano in un tuttuno estremamente efficiente sia in termini di performance di calcolo che di ritorno dell’investimento per tutta l’azienda.
Newsletter EnginSoft Year 8 n°4 -
Nel corso dei lavori relativi alla sessione sulla simulazione meccanica sono stati presentati alcuni importanti progetti tra i quali lo sviluppo di un’innovativo sistema di contenimeto di argon liquido, commissionato dal CERN di Ginevra, che consentirà di approfondire la ricerca scientifica sui neutrini. EnginSoft ha inoltre illustrato il progetto di un veicolo filoguidabile, realizzato in collaborazione con WASS, finalizzato all’esplorazione subacquea sino a quattromila metri di profondità. La sessione dedicata alla simulazione CFD (Computational Fluid Dynamics) ha, invece, reso evidente quello che è oggi, rispetto al passato, il ruolo centrale del progettista che, attraverso sofisticati strumenti di simulazione di cui può disporre, ha l’opportunità di focalizzarsi principalmente sull’aspetto ingegneristico del problema, delegando al software l’onere di governare gli aspetti matematici di base. Progettare in CFD oggi si traduce nella necessità di avere: efficienti funzionalità di dialogo con i sistemi CAD, procedure automatiche di meshing e parametrizzazione del modello. Tema centrale della sessione dedicata all’ottimizzazione è stata l’analisi dello stato dell’arte sulla simulazione multiobiettivo, tematica molto utilizzata in ambito automotive, dimostrato dalle testimonianze di Ferrari, Iveco e Continental. Novità e successo di pubblico anche per il workshop dal titolo “La progettazione delle strutture in materiale composito” coordinato da Marco Perillo e dal suo team di ingegneri. Scopo del seminario è stato quello di condividere lo stato dell’arte dei metodi di progettazione e degli strumenti di analisi strutturale sia sul piano teorico/concettuale, sia sul piano applicativo. A dimostrazione di molte tematiche verticali sostenute da EnginSoft, grazie anche all’esperienza nel progetto BENImpact, è stato inserito nel programma un workshop dedicato all’utilizzo del CAE in campo ECO-Building e progettazione sostenibile, il riscontro è stato notevolmente positivo e ha dimostrato l’ottima integrazione del CAE anche nelle tematiche “di frontiera”. L’attività congressuale, inoltre, è stata affiancata da un’area espositiva, in cui quasi 30 tra le più importanti software house CAE, sviluppatori hardware e di applicazioni
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complementari hanno condiviso con i partecipanti le novità relative ai loro prodotti. Particolarmente emozionante la Cena di Gala organizzata presso il vicino Museo dell’Auto e della Tecnica Nicolis. Qui i visitatori, prima delle portate, hanno potuto osservare automobili, motociclette e oggetti unici da collezione di epoche differenti. “Le tecnologie di simulazione rivoluzioneranno i processi progettuali attualmente adottati dalle aziende manifatturiere” ha concluso il CEO di EnginSoft. “Oggi si dice che queste tecnologie si integrano nel processo progettuale; in futuro oramai prossimo, queste tecnologie diventeranno il processo progettuale”. Con questo messaggio diamo ai lettori appuntamento all’edizione 2012 della CAE Conference EnginSoft, sperando di accrescere ulteriormente la community di analisti e imprenditori che credono nell’innovazione attraverso l’utilizzo delle tecnologie di sperimentazione virtuale. Per ulteriori informazioni: Luisa Cunico, EnginSoft [email protected] www.caeconference.com
ATTI DELLA CONFERENZA 2011 Sono disponibili in download gli atti della Conferenza EnginSoft 2011 all’indirizzo: www.enginsoft.com/proceedings2011
Fig. 3 - L’area espositiva in cui i congressisti hanno avuto l’opportunità di dialogare direttamente con i produttori di tecnologia presenti in sala.
8 - Newsletter EnginSoft Year 8 n°4
EnginSoft CAE Conference 2011 welcomes an audience of 600 CAE users The Exhibition Centre in Verona (Verona Fiere) hosted the 2011 edition of the major event in Italy on simulation based engineering and sciences, the EnginSoft International Conference, CAE Technologies for Industry, and the ANSYS Italian Conference. EnginSoft and ANSYS had the great pleasure of welcoming over 600 attendees, among them many CAE experts and opinion leaders, to the Congress Centre in Verona on 20th and 21st October. Representatives of large companies participated and contributed to the conference program as well: Ansaldo, Piaggio, Magneti Marelli, Avio, Tetra Pak, Ferrari, Iveco, and ENI, to name just a few. Their involvement underlined how CAE technologies are being used more and more in industry. One of the goals of the Conference was to offer the participants an overall view of such technologies with presentations from industry, universities, research organizations, and technology developers. “The Conference – explained Stefano Odorizzi, CEO of EnginSoft – was organized for the first time in 1984, when technologies in the field of virtual prototyping were just studied in universities. At the time, we saw great evolution, and this is what made us decide to invest in these technologies. Today, our goal is to transfer as much information and knowledge as possible about these simulation and design tools to the experts in this field”.
Fig. 2 - Welcome desk at EnginSoft area.
Fig. 1 - Swaminathan Subbiah - Vice President, Corporate Product and Market Strategy at ANSYS - during his speach talking about future developments.
The Plenary Session that opened the event, featured the “Vision” of the Assistant Director of ANSYS Inc. and a Mini-Symposium on geo-modeling. Later on in the afternoon, the program offered to the audience a number of parallel sessions focused on different technological fields: mechanics, fluid-dynamics, optimization, process simulation, composites, etc. One of the particularly captivating presentations on current topics was the contribution by Ansaldo Energia of
Newsletter EnginSoft Year 8 n°4 -
9
Genova on High Performance Computing. Stefano Santucci, the IT manager of Ansaldo, explained the reasons why the company has left a structure with only workstations for a structure with a cluster, where the distributed hardware and the HPC were perfectly integrated thus generating an efficient computation performance and ROI for the company. In the session about mechanical simulation, some important projects were presented, such as the development of an innovative storage system for liquid argon - committed by CERN (European Organization for Fig. 3 - Some beauties inside of the Nicolis Museum - Verona. Nuclear Research) in Geneva – occasion, before the dinner started, our guests from that allows to perform in depth studies on neutrinos. On around the world enjoyed a guided tour of the large this occasion, EnginSoft explained the project of a wireexhibition rooms of the museum. guided vehicle, implemented with WASS, for underwater The CEO of EnginSoft closed the Conference saying that exploration activities of up to 4000 m under sea level. “Simulation technologies will radically change the design The CFD session stressed the central role of the designer processes currently used in manufacturing companies. nowadays, compared to the past. Today, we can focus on Now we are saying that such technologies are integrated the engineering side of the problem, thanks to in the design process; but in the next years they will be sophisticated simulation tools, by entrusting the the design process itself”. management of the basic mathematical processes to the With this message in mind, we ask our attendees and software. Designing in CFD means: effective connections readers to keep an eye out for the 2012 edition of the with CAD systems, automatic mesh procedures and model EnginSoft International CAE Conference parameterization. The session about optimization www.CAEconference.com hoping that the Virtual emphasized the state-of-the-art of multi-objective Prototyping Community will grow further and further until simulation, a topic commonly discussed in the automotive we meet again! field – as Ferrari, Iveco and Continental assured us. The workshop titled “The design of structures in composite materials”, managed by Marco Perillo and his For more information: team of engineers, also turned out to be a great success. Luisa Cunico, EnginSoft The workshop’s aim was to share the state-of-the-art of [email protected] the diverse design methods and the structural analysis www.caeconference.com tools, both from a theoretical/conceptual and applicative level. Another interesting workshop was connected to the CONFERENCE PROCEEDINGS 2011 BENImpact Project and the ECO-Building field. The results 2011 Conference Proceeding are now avaliable were incredibly positive and demonstrated how perfectly to download on: CAE is integrated in the “frontier” topics. www.enginsoft.com/proceedings2011 An important aspect of the annual event is the exhibition area. This year, nearly 30 of the most well-known CAE software houses showcased their hardware and software products. The conference attendees could hear about the latest developments and news in personal talks with some of the developers. Finally, another highlight was the Conference Gala Dinner, held at the Nicolis’ Museum of Cars, Technology and Mechanics, which houses a private collection of vintage cars and motorbikes of Mr. Luciano Nicolis. On this
10 - Newsletter EnginSoft Year 8 n°4
EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca Il 24 Novembre scorso si è tenuta a Bergamo, in occasione dell’inaugurazione del nuovo Centro di Ricerca EnginSoft presso il Parco Scientifico Tecnologico “Kilometro Rosso”, una Tavola Rotonda dal titolo “Lean Design e Competitività d’Impresa - Innovazione e moderni strumenti per il management strategico”. All’evento, al quale hanno partecipato oltre 100 Top Manager delle più importanti imprese manifatturiere italiane mentre al tavolo dei relatori si sono seduti: Roberto Formigoni (Presidente Regione Lombardia), Alberto Bombassei (Vice Presidente Confindustria), Antonello Briosi (Vice Presidente Confindustria Trento), Mirano Sancin (Direttore Generale e Consigliere Delegato del Parco Scientifico Tecnologico Kilometro Rosso), Massimo Egidi (Presidente della Fondazione Bruno Kessler), Giancarlo Michellone (già Presidente di Area Science Park di Trieste e ora Presidente GMC Consulting), Marie Christine Oghly (Presidente MEDEF, Parigi), Sergio Savaresi (professore al Politecnico di Milano) e Stefano Odorizzi (CEO EnginSoft). Durante la tavola rotonda, condotta e moderata da Federico Pedrocchi - giornalista scientifico di ‘Radio 24-Il Sole 24 Ore’, gli opinion leader, provenienti dal mondo delle istituzioni, dell’impresa e della ricerca scientifica si sono confrontati sul tema dell’innovazione quale fattore chiave di successo e competitività d’impresa anche, ma soprattutto, in tempo di crisi di mercato. È Alberto Bombassei ad entrare in tema affermando che “… le strategie applicate dalla maggior parte delle aziende italiane - non solo PMI - fondate sull’innovazione incrementale e di processo, sostanzialmente finalizzate ad abbattere i costi di produzione e migliorare la qualità dei prodotti, non sono più sufficienti”. Aggiunge il presidente di Brembo Spa “in un mercato Globale, dove i paesi in via di sviluppo e con mano d’opera a basso costo la fanno da padrone, occorre sempre più innovare per essere competitivi e mantenere la leadership”. Gli fa eco Mirano Sancin, Direttore Generale di Kilometro Rosso, che aggiunge“… è l’innovazione radicale e di prodotto che contribuisce maggiormente a spostare le attività economiche, e produttive, da un’elevata concentrazione di manodopera (sempre più difficile da reperire) ad una elevata concentrazione di conoscenza (tipica dei sistemi più evoluti) e ad aumentare la competitività delle imprese a livello internazionale”. Anche le istituzioni collaborano, con l’imprenditoria e la ricerca strutturata, alla causa comune della competitività dell’impresa-Italia attraverso veri e propri strumenti finanziari costituiti dai Bandi. “Chi non ricerca non cresce” è
Fig. 1 - Alberto Bombassei, Vice Presidente di Confindustria, che commenta il contesto di mercato entro cui le aziende italiane devono operare
lo slogan citato da Roberto Formigoni e promosso da Regione Lombardia che nel biennio 2009-2010 ha stanziato fondi per oltre 80 milioni di Euro destinati alla ricerca e all’innovazione industriale. “Nonostante le difficoltà, le aziende virtuose continuano ad innovare, innovare e ad investire nella crescita – accenna il Governatore di Regione Lombardia - in un momento di difficoltà generalizzata, le aziende investono in ricerca per cercare nuovi margini di profitto e aprirsi a quel contesto di conoscenza distribuita che caratterizza la società moderna. È questo il dato positivo - conclude Formigoni - che emerge dai primi risultati del Bando Regionale”. “Le nuove tecnologie di simulazione e di analisi predittiva sono di fatto riconosciute da molte aziende un’effettiva rivoluzione dei processi progettuali” ha affermato Giancarlo Michellone. In questo contesto di ricerca applicata ed incubatore tecnologico si inserisce a pieno titolo anche EnginSoft che da tempo collabora con l’R&D di Brembo per la simulazione di sistemi frenanti e con l’Istituto Mario Negri per applicazioni farmacologiche: realtà entrambe insediate nel Parco Scientifico. Con oltre 30 ricercatori ed ingegneri impiegati
Newsletter EnginSoft Year 8 n°4 -
Fig. 2 - Overview della platea di Imprenditori e Top Manager che hanno partecipato alla tavola rotonda organizzata da EnginSoft a Bergamo
nella sede di Bergamo, l’azienda investe sul proprio futuro e rilancia la presenza in Italia trasferendo una delle sedi all’interno di un incubatore tecnologico d’eccellenza qual è il Kilometro Rosso. “È dal 2007 che collaboriamo con il Consorzio Intellimech e con altri laboratori di ricerca inseriti nel Parco Scientifico Tecnologico - afferma Stefano Odorizzi, Presidente di EnginSoft – in questi anni abbiamo toccato con mano l’importanza di far parte di questa struttura che condivide la nostra stessa mission: sviluppo di tecnologia e innovazione”. L’evento di oggi promosso da EnginSoft, in uno dei rari casi in cui istituzioni, ricerca universitaria e impresa si riuniscono a confronto su temi strategici e di vitale importanza per il sistema-Italia, è la riprova del consenso e dell’autorevolezza che l’azienda, negli anni, ha riscosso sul mercato. Per ulteriori informazioni: Mosè Necchio - EnginSoft [email protected]
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La gestione progetto in ottica Lean Design Sviluppare processi di progettazione e sviluppo-prodotto sempre più rapidi ed affidabili è oramai riconosciuta quale una necessità strategica imprescindibile. È quanto è emerso, in estrema sintesi, dal simposio di Bergamo. Per esplorare diverse alternative di soluzioni è necessario essere rapidi e tempestivi nell’apprendere i limiti e le potenzialità di ciò che stiamo ideando e progettando. La velocità e l’efficacia nell’esplorazione delle alternative, quindi, sono profondamente legate alla capacità di sperimentazione attraverso un numero significativo di prototipi ognuno funzionale alla verifica delle intenzioni di progetto e la loro corrispondenza alle necessità del cliente. Questo approccio, mediante l’impiego di prototipi fisici, potrebbe richiedere tempo e risorse in numero incompatibile con il budget disponibile. Anche nei processi di innovazione-prodotto esistono forme di “spreco” definibile in: qualsiasi attività che non crea Valore per il cliente. Il tema su cui riflettere è che tali sprechi non sono immediatamente visibili e non sono, quindi, facilmente aggredibili se non attraverso le giuste metodologie per individuarli. La riprogettazione dei processi di innovazione-prodotto, in chiave sperimentazione virtuale, può liberare enormi energie creative e di conoscenza che frequentemente sono già presenti negli uffici tecnici e di calcolo. EnginSoft, su questo tema, sta elaborando e sviluppando iniziative ad hoc finalizzate a diffondere le metodologie di Lean Design con la relativa valutazione del ROI soprattutto attraverso l’impiego della Simulazione e della Sperimentazione Virtuale.
12 - Newsletter EnginSoft Year 8 n°4
Electromagnetic Issues for a IEEE 1902.1 “RuBee” Tag Dipped in a Fiber/Composite Laminate The IEEE 1902.1 “RuBee” communication standard defines the air interface for radiating transceiver radio tags using long wavelength signals (up to 450 kHz). Conforming devices can have very low power consumption (a few microwatts on average), while operating over medium ranges (0.5 to 30 meters) and at low data transfer speeds (300-9600 bps). In this article, the approach to model a loop tag operating at 131.072 kHz through ANSYS Maxwell v.14 is described when the sensor is dipped in a multilayer fiber/composite laminate. Some preliminary results are shown in terms of input inductance and magnetic fields. Free standing antenna modeling Fig. 1 shows the prototype and the numerical ANSYS Maxwell model of a magnetic loop antenna for the short range “RuBee” protocol. The antenna (Fig.1a) is a 42mm radius multi-turn coil made of 33 loops of a copper wire with a section radius equal to 0.25mm. The numerical model is made of a solid single wire with a circular section
Fig. 2 (a) - Prototype of the multi-turn microstrip coil and (b) Maxwell 3D model. The PCB connector is visible in the bottom of Fig. 1a. The two side copper plates are helpful to tune the antenna input impedance.
CPW fed antenna is made of 16 properly distanced 0.6mm wide microstrip copper line turns. The background scenario was modeled by imposing radiation boundaries to the problem region in order to simulate free emission into space. In the operational environment, the latter could be a lossy and/or conductive media like sea water and oil (see Table I for more details) and it should be consequently modeled with the correspondent electric characteristics.
Table I - Dielectric characteristics of some media compared with free space
Fig. 3 shows a sample of the electric current density along the loop and on the solid wire section. The imposed
Fig. 1 (a) - Prototype of the 33-turn copper wire coil and (b) geometrical details of the Maxwell 3D model. In the top of Fig. 1a the microstrip feeding line and the PCB connector are visible.
radius rls equal to 0,143cm. As indicated in the bottom of Fig. 1b, this value corresponds to the radius of a circumference with a surface equal to the sum of the 33 wire sections. The second element is a multi-turn printed loop on a 0.8mm thick FR4 laminate and it is shown in Fig. 2. The
Fig. 3 - Sample of the current density distribution along the loop
Newsletter EnginSoft Year 8 n°4 -
stranded current, constant on the wire section, is visible in the bottom left detail and, as expected, the current is constant along the loop. Fig. 4 shows a sample of the magnetic induction distribution in a plane containing the loop axis. This B field distribution is a well-known result, according to basic electromagnetic theory. Indeed, the loop length is much smaller than the free space wavelength at 131 kHz (around 2.3km), so resulting in an elementary loop design. For such elements the near field is mainly magnetic and completely decoupled by the electric field.
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some other aspects could make the printed square loop preferable, like its mechanical stability and the more accurate repeatability of the prototyping. Table II shows the simulated and measured values of the input inductance for the two configurations. For the solid loop case, the calculated value is obtained from a correspondent analytical
Fig. 6 - H field distribution along the loop axis for the wire solid ring and the printed microstrip square loop.
Table II Input inductance for the two antenna configurations Fig. 4 - Sample of the magnetic induction in a plane orthogonal to the sweep.
Even if the device is an antenna, this consideration justifies the use of ANSYS Maxwell 3D rather than ANSYS HFSS because the magnetic near field characterization provided by Maxwell 3D fully satisfies the design requirements.
model and this is in good agreement with the simulated one. The measured inductance is around 10% less than the previous cases. This disagreement results from the mismatch between the transverse section areas of the solid loop of the simulated and calculated cases and the 33-turn one of the prototype (see the bottom detail of Fig.1b). A 0.9 fill factor (Fig.1a) corresponding to the missing lighter areas of the prototype with respect to the numerical models should be considered to compensate it. An excellent agreement between simulations and measurements is apparent for the printed element. Electromagnetic modeling and analysis of the composite laminate The two prototypes would be dipped in a composite material as shown in the sample of Fig. 7. A composite laminate can be schematized as a stack-up of several plies, each of them made of a sheet of fibers filled
Fig. 5 - Details of the mesh characteristics for the microstrip printed loop
Fig. 5 shows a sample of the mesh for the microstrip printed square loop. Around 161000 tetrahedra were used for the computational domain and around 24000 for the loop. For the solid wire loop 61000 tetrahedra were necessary for the computational domain and 14000 were used for the loop. Fig. 6 shows the H field distribution along the loop axis, for both configurations. The H field is higher for the wire loop, suggesting the use of this antenna type. However,
Fig. 7 - Sample of rectangular loop dipped in a fiberglass composite laminate.
14 - Newsletter EnginSoft Year 8 n°4 isotropic, in the sense that only their intrinsic dielectric characteristics are known. On the other hand, the structures in Fig. 8b and c are generally anisotropic, as a result of the applied methodology. The permeability and permittivity tensors need to be calculated according to the material properties and to the problem geometry, as:
Fig. 8 - Single composite ply: (a) schematic model, (b) equivalent model for the intermediate fiber/resin layer, (c) equivalent model for each single ply
where:
and g is a function of the ratio between the fiber and the resin volume in the intermediate layer of Fig. 8a. Fig. 9 shows the Maxwell 3D model with 4 plies above and 4 plies below the wire antenna. Fig. 9 - Example of a composite laminate made of 8 plies: 4 above and 4 below the wire loop antenna
with some dielectric resin, as shown in Fig. 8a. An df thick intermediate layer made of some fibers and resin lies between two dr thick single layers of resin. This structure could generally be dissipative, conductive and anisotropic, the latter depending on the characteristics and the distribution of the fibers.
Each ply has been modeled in Maxwell 3D, including all the material anisotropies and dielectric properties. The work on the analysis of the effect of a number of plies up to 64 is in progress. They have been fully parameterized in order to take into account a number of possible ply configurations and materials.
An effective approach to model this structure is to define an equivalent layer for each ply. Many models have been recently presented, resorting to different approaches but all of them afford a specific problem without deeply challenging a general approach. In the framework, the approach to model an equivalent layer for each ply is to apply the method described in for the intermediate layer of Fig. 8a, in order to get an equivalent anisotropic intermediate one, shown in Fig.8b.
Conclusions In this work, the approach to analyze the electromagnetic performance of a tag antenna for the IEEE 1902.1 “Rubee” protocol has been described through the use of ANSYS Maxwell. Preliminary results have been shown in terms of radiated magnetic field and input inductance for both numerical models and prototypes. Simulated and measured results are in excellent agreement, proving the tool reliability. The methodology to model a multi-ply composite fiber material has been defined and numerical analyses on the antennas’ performance in its presence will be the main topic of some future investigations.
Then, a circuital approach can be applied to the multilayer structure shown in Fig. 8b to result in a single layer equivalent anisotropic model. It is worth noticing that all the constitutive materials (fibers and resin) in Fig. 8a are
Per ulteriori informazioni: Andrea Serra, EnginSoft [email protected] Thanks to Federica Bolognesi, IDNOVA
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Structural Optimization of a Car-body High Speed Train - An Innovative Analysis and Design Methodology In the past, the main challenge was to achieve a very high speed, but today the criteria such as energy efficiency, high transport capacity, comfort and low environmental impact are becoming more and more important. For this reason the philosophy of AnsaldoBreda is to combine a settled design process with innovative approaches to optimize the reliability, safety, low power consumption and an easy maintenance. In order to be competitive in the market, especially in this economically challenging period, it is necessary to push the envelope of the available technologies to ensure compliance with top level quality standards. A new methodology approach has been developed by exploiting the new capabilities of the multi-objective design environment modeFRONTIER and it has been applied to the design of the carbody structure of a new generation of High Speed trains. In this context, the aim of the activity was the design optimization of the aluminum carbody structure in terms of weight and dynamic behavior, respecting all project constraints according to the high standard structural and crash requirements of European EN 12663 - Category P-ll (Fixed units) and TSI Rolling Stock. Starting from the CAD model of the original configuration, the FE comprehensive parametric model has been developed by ANSYS APDL procedure and integrated into the
modeFRONTIER optimization platform to achieve the requested goals. The FE parametric model has been divided into two different main parts: 1. The central parts of the carbody (named “fuselage”) – as shown in fig.1a; 2. The terminal tapered parts of the carbody – as shown in fig.1b. The fuselage geometry (fig.2) is completely parametric in terms of:
Fig.2 - Section profile of carbody
a) number of the profile reinforcements; b) angle, position of reinforcements; c) thickness of reinforcements; d) thickness of external and internal skin of profiles. The aims of the optimization process of a carbody in modeFRONTIER are: a. Minimizing weight b. Maximizing two first own frequencies Fig. 1a - Fuselage Parametric part of high speed train: it has been completely development in ANSYS APDL. Fig. 1b: No -parametric part of high speed train: terminal tapered parts are fixed geometry
with the following constraints: a. Max Von-Mises stress for static analysis
16 - Newsletter EnginSoft Year 8 n°4 b. Max Von-Mises stress for equivalent crash analysis c. Max Von-Mises stress for fatigue analysis d. Min buckling factor for linear instability analysis The original configuration, only referred to the parametric part of the carbody, weighs 5.927 Tons. The main goal is the weight reduction by min. 500 Kg, maintaining the first bending frequency of 11 Hz. The static structural analysis and fatigue analysis have been performed for both welded and unwelded region (fig.3), which have different material features:
Only the modal analysis has been performed to find out the best region for weight and frequency with no timeconsuming run (less than 1 hour on the cluster machine). The results of this first optimization loop has been used as a starting DOE (Design of Experiment) for the second one, where objectives/constraints related to displacement under pressure loads and to the 5-6 strongest load cases (fig. 4) have been introduced. This step is more time-consuming than the first one (5 hours on the cluster machine). After these optimization loops, some variables have been changed in agreement with AnsaldoBreda, and the final
Fig.3 - Section of a carbody structure
Due to the high number of time-consuming simulation and the high number of input variables, a progressive approach has been studied for the optimization analysis. Therefore, the optimization analysis has been carried out in three steps: • Step1: Screening, driving towards the best designs region; • Step2: Rough refinement, including the most important constraint conditions; • Step3: Final refinement, achieving the optimal solutions.
optimization run has been done to achieve the best solutions. Since this step was really time-consuming (15 hours on the cluster), the problem has become to monoobjective: only the weight has been considered, while the other objective has become constraints (fig. 5). The set of best designs belonging to the new Pareto frontier has been verified for each operative load condition and the best designs have been chosen using decision making tools. The optimal designs selected on the basis of stress and weight values have a considerable variation of both external and internal skin thickness, which can cause manufacturing problems. In order to avoid such problems, another post processing analysis has been done to find out Pareto solutions with a homogeneous distribution of thickness
A total of 23 different working -load cases have been considered, with an additional specific comfort requirement about Static Pressure load (-8 KPa inside Tunnel) which constrained the side walls displacements (Uy < 3mm and Uz < 4.5 mm) The whole simulation took 3 weeks on cluster machine with 8 parallel simulation (32 core). The first optimization step has been carried out taking into account the two most important objectives of the problem (increase of frequency and weight reduction) which lead the designs to the best region Fig.4a - History of weight convergence and allows to reduce the design (green points: 1st optimization loop; blue points: space of the input variables. 2nd optimization loop).
Fig.4b - displacements in y direction (mm)
Newsletter EnginSoft Year 8 n°4 -
along external and internal skin. New post processing using “parallel chart” applied on best design has been carried out in order to find a suitable solution matching the new requirements introduced a-posteriori (fig. 6). Table II shows the comparison between the best design selected at the end of the optimization analysis (Design ID 378) and the best design after the last post processing considering a thickness uniformity (Design ID 339). Thanks to the implemented methodology and the optimization routine, a considerable weight reduction has been reached. The chosen solution, Design ID 339, has a weight reduction of 546 Kg (- 9.2%) and it has a more uniform thickness variation which simplifies the carbody manufacturing. This work aims to shows how to exploit new design methodologies and new technologies in order to manage industrial design processes that involve a large number of variables (more than 50), several constraints and objectives, finding the best solution according to industrial timing. It is possible to summarize the most important steps of this activity, as follows: • The design optimization procedure developed has been completely automated: this allowed to make the most of all available hardware and software resources, completely exploiting the downtime (nights and holidays). • The requested weight reduction has been achieved respecting every structural and comfort requirements: this has totally fullfilled the expectations of the modeFRONTIER industrial users. • The additional requirement about manufacturing has been fulfilled without rerun any analysis thanks to the new methodology approach: this has been possible thanks to the really powerful capabilities of the post-processing tools of modeFRONTIER. • The optimization methodology can be completely re-used for other design processes: this activity was dedicated to a specific carbody but this approach can be easily adapted also to other railway vehicles. For more information: Francesco Franchini, Enginsoft [email protected]
Fig.5 - The workflow of modeFRONTIER with all input and output variables, the final objective and constraints
Table I - The table above summarize the optimization strategy adopted. The total number of design has been run in 20 days
Fig.6a - Parallel chart of the best designs
Fig.6b - The selected design (Design ID 339) with homogeneous thicknesses
Table II - comparison between the original solutions and the optimized solutions
Table III - Thickness comparison of the side walls of fuselage (profile ref. 5-6-7-8)
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FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis Finalized to the Structural Verification of the FSO Mooring System Strength and Fatigue Verifications of an FSO mooring system have been performed basing the results on proper hydrodynamic analysis (developed inside ANSYS-AQWA) and structural analyses (developed inside ANSYS-Workbench) of the system and relevant components. Hydrodynamic Analysis The FSO (109.000 DWT), operated by Edison, is moored on the Rospo Mare Offshore Oil Field. The FSO mooring is guarantees via 6 chains connected to a rotating turret, installed at the FSO bow. During the oil offloading operation, the Shuttle Tanker (45.000 DWT) is moored, via an hawser, at the FSO aft end. The offloading operation takes place under proper sea conditions, with waves characterized by significant height (Hs) ad zero up-crossing period (Tz). To each sea state, consistent current and wind have been accounted for. The hydrodynamic model (performed inside Ansys-AQWA suite), simulating the FSO and the Shuttle Tanker (this one moored, at its stern, to a Tug via a mooring cable), refers both to aligned and misaligned meteo conditions (current incoming at 50 degrees with respect to wave direction, wind incoming at 25 degrees with respect to wave direction). On the model (FSO + Shuttle Tanker + mooring lines), time domain hydrodynamic analysis has been performed for each defined sea-state, obtaining, for each mooring chain and for the hawser connecting FSO and Shuttle Tanker, the axial tension as function of time. In order to check the strength resistance of mooring components (such as Chain Stoppers and 'Ecubier') installed at the rotating turret, besides hydrodynamic analyses under offloading conditions, also hydrodynamic analyses of FSO in moored condition, for extreme storm case (100 years return period), have been performed. Strength and Fatigue Verification of Chain-Stopper and “Ecubier” Based on results of hydrodynamic analysis performed for both extreme and offloading conditions, strength and fatigue verifications of Chain Stopper and ‘Ecubier’ have been performed. Strength checks have been based on results obtained from contact non-linear analysis performed of Finite Element
Model of Ecubier + Chain Stopper under extreme load case (practically the chain minimum breaking load). Fatigue checks have been developed according to spectral approach as required by DNV OS-E301 (Position Mooring), assuming proper S/N curve data as reported in DNV RP-C203 (Fatigue Design of Offshore Steel Structures). The assumed hypothesis at the base of fatigue spectral approach is that the stress range, S, is a random variable characterized by a probability density equal to p(S) and that, for each sea-state, the number of cycles having stress variation in the range of S and S+dS is directly related to ni p(S), where ni is the total number of cycles of that sea-state. Based on this and on the fact that, for offshore structures, the probability density of stress ranges, p(S), can adequately be represented by a Rayleigh distribution, the
Fig. 1 - Hydrodinamic Model of FSO, Mooring Lines, Shutter Tanker
Fig. 2 - Von Mises Stress distribution on Ecubier and Chain Stopper
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damage, Di, for the i sea-state, is given by the following relation:
Fig. 3 - Finite Element Model of Ecubier and Chain Stopper
where a and m are factors of S/N curve (C curve has been considered for fatigue verification of Ecubier and Chain Stopper), while σs is the standard deviation of S distribution. Finally, based on Miner-Palmgreen relation, the total damage, D, due to the summation of damages of each seastate, Di, is:
Enrico Miorin, Fabiano Maggio, Livio Furlan EnginSoft
Fig. 4 - S/N Curves in sea-water with cathodic protection
For more information: Livio Furlan, EnginSoft [email protected]
Design and FEM Analyses in Offshore and Oil&Gas Industry Besides competencies in Automotive, Aerospace and Industrial Engineering Simulations, EnginSoft has knowledge also in the Design and Analyses voted to the Oil&Gas and Offshore Industry. Many consultancy activities have been performed via collaborations with the most important Italian players in this sector: ENI, Saipem, Tecnomare, MIB Italiana, Petrolvaves, Cameron, FBM, Officine Resta, Nuovo Pignone, ATB, Foster Wheeler. EnginSoft can supply a full range of services covering projects entire design route, from the earliest conceptual studies passing through FEED and basic design up to detailed design and installation engineering. The following list reports some of the Oil&Gas Business Unit competences: • Conceptual and detailed design and structural analysis of fixed offshore platforms (jacket, top-sides, buoyancy tanks, stiffened structures) • Design and analysis of subsea foundation templates • Design and analysis of pressure vessels, valves, piping, rack, etc. • Design and analysis of subsea manifold (even for installation, repairing and retrieval operations) • Detailed structural analysis of structural parts (Hulls, Deck, etc.) of Semi-Submersible Vessels • Detailed structural assessment of steel Gravity Based Structures (GBS) including stiffened plate code checks • Detailed design and structural analysis of risers and FPSO's mooring connectors • Revamping of fixed offshore platforms (assessment of structural reliability- re-certification and life extension), fracture and fatigue assessment of installed jacket structures (risk analysis) • Motion Analysis of Floating Vessels (even for Marine Pipeline Installations) The BU, which is located in EnginSoft Padova Office and is coordinated by Livio Furlan, has high skills also in the field of structural and mechanical applications in general (as an example the design and analysis of Roller Coaster structures and cars or the design of large valves for hydroelectric power plants). For more information: Livio Furlan, EnginSoft - [email protected]
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Numerical Analysis of a Micro Gas Turbine Combustor Fed by Liquid Fuel This work presents a CFD analysis of the combustion chamber of a 50 kWel nominal power micro gas turbine. The purpose of the analysis is to investigate the combustion process and performance of the combustion chamber fed by liquid fuels, through 3D numerical simulations performed with ANSYS CFX 13.0. Firstly, a sensitivity analysis was carried out in order to determine the parameters for the correct modeling of the liquid injection. Then, a simulation campaign was conducted to investigate the case of Jet A feeding and the supply with different liquid fuels deriving from biomass. Introduction Nowadays micro gas turbine (MGT) are one of the more flexible and effective system for the distributed and residential micro cogeneration, due to their compact size, the low operating and maintenance costs, their greater overall conversion efficiency and reduced environmental impact. The continuous flow operation of this system offers a greater flexibility with respect to the unsteady process of internal combustion engines that imposes constraints on fuel characteristics. In particular, MGTs can be supplied with fuel (both gaseous and liquid), characterized by a higher level of contamination thanks to their greater adaptability to different fuel supply. Among the renewable sources, an increasing interest has been shown in fuels derived from biomass since they are a predictable source, allowing the distributed grid-connected generation without causing discontinuities in the electric grid and frequency instabilities. At the same time, vegetable oils have gained attention since they can be low-cost fuels and allow to implement
systems for the distributed energy production. MGTs are not well-established systems for straight vegetable oil feeding, yet, because the combustion of these oils had to be investigated due to the opposite physical and chemical characteristics, such as the chemical composition, the lower heating value (LHV), the molecular mass, the density and the viscosity, compared to diesel, biodiesel, dieselvegetable oils and their mixtures. In fact, the combustion performance depends on the atomization process and spray characteristics, which are directly related to the fuel composition and its physical properties, in particular the high viscosity of vegetable oils. The study presented below regards the preliminary analyses performed on a MGT combustion chamber fed by conventional fuel (Jet A), in order to find the correct settings for the simulation of biofuel feeding. Computational domain and numerical models Geometry. The numerical analysis have been conducted on the combustion chamber of Solar T62-T32, a micro gas turbine of 50 kWel nominal power, fed by diesel fuel. The combustion chamber (Figure 1a) is a reverse-flow annular type combustor, with six fuel injectors, 24 dilution holes and a series of holes for the cooling of the liner wall. The air from the compressor enters the combustion chamber in counter-current with respect to the combustion gases, passing through the space between the external wall and the liner’s wall. The solid domain of the combustion chamber (Figure 1b) was obtained from the direct measurement of the real geometry (Fig. 1a). Thanks to the periodicity of the number of fuel nozzles, dilution holes and wall cooling holes, the fluid domain was reduced to a 60° annular sector of the combustor (Figure 1c).
Figure 1 - (a) real combustor geometry, (b) solid domain, (c) grid of the fluid domain.
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parameters that better predict the behavior of this type of combustor, sensitivity analyses on the boundary conditions have been carried out. Boundary conditions influence One of the ways to reduce the particle spray diameter and, therefore, to obtain a finer spray, is to increase the atomizing air mass flow, which also applies to high viscous fuels. A larger flow of atomizing air can be obtained by modifying the bypass Figure 2 - Comparison of the results of the air/fuel ratio variation: temperature distributions. from the main machine compressor or by adding external air from an auxiliary compressor. So the influence of the air mass flow coming from the compressor has been evaluated. The air mass flow to fuel mass flow ratio, AFR, was varied from the standard value of 70 to 50 (rich combustion) and 100 (lean combustion). Figure 2 shows the comparison of the temperature contour plots in the nozzle mid plane: the flame increases in terms of extension and intensity as α increases, as Figure 3 - Comparison of the results of the particles’ diameter variation. expected. The quantitative results showed that the values of the turbine inlet Grid. Two unstructured tetrahedral grids with an overall temperature (TIT) and pollutant emissions, such as NOx and number of elements approximately equal to 1.5 and 2.5 CO, of the case of standard air/fuel ratio (ARF = 70) are in million respectively were generated using ANSYS ICEM CFD. good accordance with the measured pollutant Both grids are characterized by a uniform distribution of the concentrations and the calculation of the TIT by means of a elements inside the domain, with a more refined mesh gas turbine Cycle Deck. For these reasons, an air/fuel ratio inside the nozzle and combustion zone. of 70 was chosen for the subsequent simulations. The sensitivity analysis of the grid showed that both grids achieved the numerical convergence and were robust with Spray parameters influence compared to the overall performances of the combustor. For The simulation of liquid fuel combustion has been carried these reasons the 1.5 million elements grid (Fig. 1c) was out defining a particle injection region placed nearby the used in the numerical analyses presented below. fuel inlet surface, which is closed to the exit of the fuel injection duct. Sensitivity analyses concerning the diameter Numerical models and boundary conditions. The numerical of the particles injected into the combustor and the angle models adopted are: the k-ε for turbulence, the Eddy of the injection cone have been performed: in particular, Dissipation (EDM) for combustion with a 2-steps reaction three diameter sizes (1, 10, 20 µm) and three injection scheme and a PDF model as the NOx formation method. A cone angles (10°, 20°, 30°) were investigated. particle injection region and the TAB (Taylor Analogy Breakup), as secondary breakup model, were set at the fuel In the case of variation of the particle diameter, the flow inlet surface in order to model the fuel spray, while the field and the temperature distributions in the nozzle mid primary breakup was not activated. An adiabatic boundary plane have not presented significant modifications. The condition was set for all the combustor walls. Fuel inlet values of TIT and pollutant emissions (NOx and CO) boundary condition was set according to the data provided calculated at the outlet surface of the combustor has by the manufacturer, while the air mass flow value was decreased as the particle diameter has increased, according obtained from literature. All the numerical simulations were to the liquid fuel combustion phenomena. The evaporation performed with ANSYS CFX 13.0. time of the particles has increased as they have increased in size, while the particle traveling distance has increased CFD Analysis of the combustion chamber in an irregular way, as shown in Figure 4. A great increase Case of conventional fuel feeding has occurred passing with diameter between 10 and 20 µm In these cases the simulation regards the supply with and a decrease has occurred with a diameter between 1 and conventional fuel, so the Jet A fuel of the CFX material 10 µm. This was probably due to the size of the grid library has been used. In order to determine the simulation elements. Nevertheless, numerical values were in
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Figure 4 - Comparison of the results between Jet A and mock biofuels: particle traveling distance and temperature distribution.
accordance with it. When the spray cone angle has varied, the vaporization time and the traveling distance of the particles increased as the cone angle has increased. Temperature values into the primary combustion zone are lower in the case of a cone angle of 30°; the TIT value decrease accordingly. An anomalous behavior occurred when cone angle of 20°: there is a reduction of the particle traveling distance and the evaporation time; the TIT value is in accordance with the other simulated cases. According to the results of the sensitivity analyses already performed, an air/fuel ratio of 70, a diameter of 10 µm for the particle injection and a spray cone angle of 30° have been chosen for all the simulation presented below. Case of vegetable oil fuel feeding Subsequently, some simulations have been performed in order to investigate the behavior of the combustor in case of feeding with liquid fuel derived from biomass. As first attempt, two mock biofuel have been created starting from the Jet A characteristics and modifying only some of the parameters (density and viscosity values), in order to determine the influence of a single parameter each time. The density value, equal to 914 kg/m3 at 20 °C and the dynamic viscosity value, equal to 40 cP at 20 °C, comes from a direct measurement of a sample of rapeseed oil derived from dedicated crops (experimental crops realized within a research project on short energy chain). As a reference, default Jet A density and viscosity values at 20 °C are 780 kg/m3 and 1.5 cP, respectively. Figure 4 shows that the temperature distributions of the mock biofuels differ from the Jet A feeding in terms of intensity and flame morphology. The maximum temperature values in the mock biofuel cases are higher than the ones in Jet A case within the primary combustion zone, and the flame of Jet A case is more stable and there is less variation in temperature values. In terms of flame morphology, the base of the flame starts at the nozzle exit in Jet A case, while in mock biofuel cases it seems to even start inside the
nozzle. The highest values in the primary combustion zone are probably due to the lower flow velocity that produces an increase in the residence time, which come out from the analysis of the velocity field and the particle traveling distance pattern. The average values of TIT, NOx and CO calculated at the outlet surface of the combustor are not influenced by the density and viscosity variation.
Conclusions The aim of this work is to study the combustion phenomena related to the liquid fuel feeding of the annular combustion chamber of a micro gas turbine with an electric power of 50 kW. The main parameters of the fuel spray were investigated in the case of conventional fuel supply (Jet A) setting different values of particle diameter and cone injection angle. No significant modifications in terms of flow field and temperature distributions were noticed from the sensitivity analyses on spray parameters. The values of TIT and pollutant emissions (NOx and CO), calculated at the outlet surface of the combustor, decrease as the particle diameter increases, according to liquid fuel combustion phenomena. The evaporation time of particle and the particle traveling distance increase as dimension and cone angle increase, leading to slower combustion and, at the same time, a longer flame in the combustor. Particles with a diameter of 1 µm present an anomalous behavior in terms of the particle traveling distance and mean particle diameter, which is probably due to the size of the grid elements. Subsequently, a numerical analysis was performed in case of biofuel supplying. A mock biofuel was used by setting the values of density and viscosity of a rapeseed vegetable oil obtain from mechanic extraction of dedicated crops. The setup of the model parameters was performed by starting from the sensitivity analyses carried out in case of Jet A feeding. The analysis of the particle track shows that there is an increase in the particle traveling distance and the particle time as the fuel viscosity increases and the consequent increase of the residence time. This leads to higher temperature values inside the primary combustion zone. The global performance of the combustor (TIT and pollutant emissions) are not influenced by changes in density and viscosity.
Michele Pinelli, Anna Vaccari Università degli Studi di Ferrara
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Reconsidering the Multiple Criteria Decision Making Problems of Construction Workers Using Grapheur We are dealing with a series of multiple criteria decision making problems and analysis related to Canadian construction projects including waste management, productivity improvement, human and IT factors, emergy based lifecycle, and process optimization. The urgent increase of using IT in construction projects has been considered as one way to improve the process of solving our problems. Construction project managers have to make tough decisions. They have been considering different IT tools and would like to invest on getting better data analysis tools for enhancing their decisions. However, making critical decisions for complicated and multiple criteria construction projects problems in which huge amount of data are involved is not a simple task to do. As the della Ford allo 'iPod' di Apple, essi hanno identificato i principi e gli strumenti per neutralizzare la concorrenza e creare uno spazio di mercato incontestato, dalle possibilità illimitate come quelle di un oceano blu. Strategia Oceano Blu porta un messaggio carico di ispirazione: il successo non dipende dalla concorrenza spietata né da costosi budget di marketing e R&S, ma da mosse strategiche brillanti, adatte a un uso sistematico da parte di tutte le imprese.
Dettagli del libro Titolo: Strategia oceano blu. Vincere senza competere Autori: W. Chan Kim, Renée Mauborgne Editore: Etas Collana: Management Data di Pubblicazione: 2005 ISBN: 8845308480 ISBN-13: 9788845308482 Pagine: 288
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GPU ACCELERATED ENGINEERING with ANSYS also required for going parallel for greater than 2 CPU cores. For academic license users, the GPU capability is included with the base ANSYS Academic license that provides access to ANSYS Mechanical. How much more could you accomplish if simulation times could be reduced from one day to just a few hours? As an engineer, you depend on ANSYS Mechanical to design high quality products efficiently. To get the most out of ANSYS Mechanical 13.0, simply upgrade your NVIDIA Quadro GPU or add a NVIDIA Tesla GPU to your workstation, or configure a server with NVIDIA Tesla GPUs, and instantly unlock the highest levels of ANSYS simulation performance.
Here is an example of the speed-up you can reach within ANSYS13.
With the upcoming ANSYS Mechanical 14.0 engineers will even more benefit from NVIDIA GPUs.
With ANSYS® Mechanical™ 13.0 and NVIDIA® Professional GPUs, you can improve your product quality with 2x more design simulations or you can develop high fidelity models with practical solution times. This accelerates your timeto-market by reducing engineering cycles. The amount of acceleration achievable when using the GPU will vary greatly depending mostly on the model of the simulation, but also on the hardware configuration being used. To get the best speed-up the simulation should spend most of its time in the matrix solver operations rather than other tasks, such as matrix assembly. Also the problem size should be between 500K to 8,000K DOFs for the sparse direct solver and 500K to 5,000K DOFs for PCG/JCG iterative solvers. To unlock the GPU feature in ANSYS Mechanical 13.0, you must have an ANSYS HPC Pack license, the same scheme
NVIDIA and ANSYS have collaborated to bring you the power of GPU computing for ANSYS. With the latest release of ANSYS R13, NVIDIA GPU acceleration enables faster results for more efficient computation and job turnaround times, delivering more license utilization for the same investment. This will continue with even more features and optimizations in the upcoming release of ANSYS.
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EnginSoft continua l’attività sui materiali compositi La progettazione di un componente in materiale composito rappresenta una sfida complessa ad elevato contenuto tecnologico che coinvolge attualmente settori industriali profondamente diversi, dall’aerospace alla nautica, sino all’automotive ed applicazioni sportive più spinte. Il CAE svolge un ruolo sempre più importante in questo senso, rappresentando lo strumento in grado di riprodurre in maniera fedele ed accurata un prototipo virtuale dei componenti realizzati in materiale composito. ESAComp ed ANSYS Composite Prep/Post rappresentano ad oggi lo stato dell’arte dei software per la simulazione dei compositi; il loro avvento, sin dalle prime release, ha permesso di superare definitivamente i limiti intrinseci del classico approccio seguito per la progettazione delle strutture in composito, consentendo una caratterizzazione dettagliata dei materiali di base (fibre, matrici, core in schiuma o honeycomb, ecc.), una accurata gestione della laminazione attraverso la simulazione delle fasi tecnologiche di stesura dei tessuti (Draping & Flat Wrap) e una dettagliata verifica degli stati tensionali avvalendosi di Failure Criteria polinomiali (Tsai-Hill, TsaiWu, ecc.) e basati sulla natura fisica dei compositi (Hashin 2D/3D, Puck 2D/3D, ecc.). EnginSoft, attraverso l’organizzazione di seminari a tema dal taglio fortemente tecnico, è costantemente impegnata in attività di formazione avanzata; l’obiettivo principale è quello di sensibilizzare le società leader nel settore ed i principali istituti di ricerca nella valutazione dell’efficienza dei nuovi software numerici al fine di affrontare in maniera efficace anche le problematiche più ostiche e profonde. Il seminario “Progettazione delle strutture in materiale composito”, svolto il 21 ottobre a Verona nel contesto dell’”EnginSoft International Conference 2011”, è stata un’ottima occasione di ritrovo per tutti coloro che quotidianamente si ritrovano a dover affrontare tematiche complesse relative al mondo dei compositi; i consensi raccolti dimostrano che l’evoluzione del CAE, attraverso l’avvento di strumenti di prototipazione virtuale come ESAComp ed ANSYS Composite Prep/Post, ha generato un nuovo modo di concepire la fase di progettazione delle strutture, attraverso una sensibilità completamente rinnovata focalizzata all’efficienza computazionale, alla
drastica riduzione del time-to-market ed all’accuratezza dei risultati raggiunti. Il seminario è stato replicato il 4 novembre a Marina di Ravenna, nell’ambito dei “Seminari Nautilus” organizzati dalla Facoltà di Ingegneria dell’Università di Bologna. L’evento anche in questa occasione è stato seguito con particolare interesse da operatori del settore industriale, in particolare nautico, e della ricerca scientifica. La formazione avanzata sui nuovi software di simulazione per le strutture in composito rappresenta senz’altro un punto cardine per EnginSoft, che continuerà ad investire in eventi e seminari mettendo a disposizione competenze e strumenti CAE d’avanguardia. Per ulteriori informazioni: Fabio Rossetti, EnginSoft [email protected]
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EnginSoft presenterà la release 5.2 di MAGMA a METEF 2012 Il Metef, la fiera di riferimento per l’industria metallurgica, si terrà presso la Fiera di Verona dal 18 al 21 Aprile 2012. EnginSoft, come consuetudine, sarà presente con uno spazio espositivo in cui verranno presentate le nuove release dei sotware sostenuti relativi alla simulazione di processo, in particolare ci sarà la preview di MAGMA 5.2. A novembre 2009 è uscita la prima versione di MAGMA 5, la 5.0, che permetteva, in un ambiente completamente nuovo,
di affrontare virtualmente tutti i processi di fonderia basati su sabbia (ferrosi e non ferrosi). Con la versione 5.1, attualmente disponibile, sono stati integrati tutti i moduli, consentendo agli utenti di affrontare lo studio di tutti i processi di fonderia, dalla conchiglia in gravità alla bassa pressione, alla pressocolata in camera calda e in camera fredda ecc. Per i primissimi mesi del 2012 è prevista l’uscita della versione MAGMA 5.2. In questa versione sarà disponibile MAGMA C+M, un nuovo modulo, che permetterà di simulare la produzione delle anime con diversi tipi di leganti e di sabbie. Questo modulo consentirà di simulare la fase di riempimento delle casse d’anima e la fase di indurimento delle anime, permettendo di valutare le problematiche del processo produttivo e porvi rimedio con soluzioni correttive. MAGMA 5.2 consentirà inoltre, nell’ambiente di visualizzazione dei risultati (postprocessore), di confrontare direttamente simulazioni di differenti versioni permettendo di analizzare i risultati sia come singola immagine che come filmato in stato di avanzamento. Sarà possibile sincronizzare i filmati delle versioni a confronto per garantire una più semplice ed
efficace comparazione dei risultati selezionati. Grazie al tool “User Results”, presente nell’ambiente di visualizzazione dei risultati, sarà possibile elaborare nuovi criteri di valutazione, combinando i risultati forniti dal software. Tale procedura sarà resa possibile da un fornito compilatore matematico. Sarà infine possibile sfruttare la visualizzazione dei risultati sfruttando sistemi 3D, che permetteranno una visualizzazione in profondità dell’oggetto analizzato. MAGMA 5.2, come l’attuale versione 5.1, sfrutta la tecnologia Java, che permette un diretto interfacciamento con gli attuali sistemi operativi Linux e Windows a 64 bit, a garanzia delle più elevate performance di calcolo. METEF-FOUNDEQ, giunto alla nona edizione, rappresenta l'evento di riferimento per le tecnologie per l'alluminio e la fonderia. Grazie alle tante iniziative messe in campo, anche nel 2012 METEF-FOUNDEQ, attrarrà buyer da tutto il mondo interessati ad acquistare impianti, macchine, attrezzature per la produzione e la trasformazione dei metalli; componenti estrusi, colati e laminati; prodotti e materiali per il trattamento e la finitura. Per ulteriori informazioni: Piero Parona, EnginSoft [email protected] Sito web dell’evento: www.metef.com
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La simulazione di processo nella progettazione di radiatori Estetica e integrità di prodotto sono due fattori fondamentali per la produzione di radiatori, ma altrettanto importante è saper rispondere alle esigenze del mercato in tempi rapidi con costi competitivi. Il processo produttivo utilizzato per questo genere di produzione corrisponde alla colata in alta pressione. Tale processo, per le caratteristiche e i ridottissimi tempi di produzione dovuti all’iniezione forzata della lega negli stampi, richiede la massima precisione ed il controllo assoluto dei parametri imposti alle macchine da pressocolata. Per assolvere a queste richieste è fondamentale ridurre al massimo gli sprechi di produzione, comprimendo il più possibile i tempi di progettazione/realizzazione del prodotto. In questo contesto la progettazione prodotto/processo assume un ruolo di considerevole importanza: è infatti in questa fase molto delicata dove vengono valutate le soluzioni più efficaci per la realizzazione delle attrezzature ed i più adeguati parametri di processo. Sviluppare ed ottimizzare un processo produttivo significa identificare le variabili che maggiormente influiscono sulle caratteristiche del prodotto, valutandone gli effetti. Questo può essere perseguito attraverso un approccio al lavoro di progettazione che includa la simulazione di processo. Il caso che verrà proposto all’High Tech Die Casting 2012, che si terrà a Vicenza il 9 e 10 Febbraio 2012, riguarda la produzione di una specifica linea di radiatori progettati e prodotti dal Gruppo Ferroli. EnginSoft è stata coinvolta nell’attività di riprogettazione delle attrezzature al fine di ridurre al massimo gli scarti presenti nella linea produttiva, incrementando al massimo la qualità estetica e di tenuta del prodotto. Lo studio svolto ha avuto come obiettivo principale la ricerca del miglior sistema di colata per ottenere la massima qualità del componente e ridurre al minimo il rischio di inglobamenti d’aria, principale causa di scarto nel processo di pressocolata in produzione. La riprogettazione delle attrezzature ha inoltre permesso di incrementare la produttività e ridurre i costi. La collaborazione fra il Gruppo Ferroli ed EnginSoft ha determinato il successo del progetto, permettendo un rapido avvio della produzione. Per ulteriori informazioni: Giampietro Scarpa, EnginSoft [email protected]
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modeFRONTIER Users’ Meeting 2012
This year the International modeFRONTIER Users' Meeting 2012 (UM12), sponsored by ESTECO, will take place on 21st and 22 May 2012 at the Savoy Palace in Riva del Mandracchio Excelsior in Trieste. UM12 provides a unique forum to discover how engineering and academic experts apply the latest methods and techniques to optimize simulation design processes. The meeting of global significance has traditionally brought together experts from leading companies such as FIAT, Honda, Jaguar, Bombardier and many others. The issues relate to the operating logic of modeFRONTIER and its applications in different companies with high technological interest. ESTECO's biannual event is coming to its 5th edition, marking 10 years of exchange of best practices and ideas among modeFRONTIER enthusiasts. The leit-motiv of 2012 is Collaboration: nowadays sharing knowledge and team working are imperatives for any successful company. Technology helps breaking the barriers between disciplines, teams and field, encouraging knowledge sharing and enhancing working in team. It is not by chance that this concept is the main theme of the upcoming event, as modeFRONTIER provides a unique multidisciplinary software platform utilized in a wide range of fields all over the world. UM12 is not just a meeting of modeFRONTIER users, but it’s open also to the academic world: students and researchers are welcome to attend the event, and have the chance to look closely at industrial applications while getting the possibility to present in front of a knowledgeable audience. Guest of honor of the 2012 edition is David Edward Goldberg, the leading expert of genetic algorithms, although his expertise spans multiple disciplines. He has been Director of Illinois Genetic Algorithms Laboratory (IlliGAL) and Professor at the Department of Industrial and Enterprise Systems Engineering (IESE) of the University of Illinois. He will present two talks: one about collaborative engineering as part of the official UM12 agenda, and another one, open to the general public, concerning the relationship between higher technical education and society. For more information: http://um12.esteco.com/um12/
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EnginSoft GmbH Silver Sponsor at the ANSYS Conference & 29th CADFEM Users’ Meeting 2011 EnginSoft GmbH sponsored the ANSYS Conference and Users’ meeting, held this year at the Stuttgart International Congress Center. The ANSYS Conference focused on Electric Mobility Technologies, Machine Tools, Wind Energy Systems, Electronic Products Design, Building and Environmental design and Bio-Engineering Simulation.
that are difficult to combine when running aerodynamic shape optimization, although both the concepts are required to advance the transportation industry. High Speed Trains have to withstand the increasing efficiency requirements and emissions restrictions, hence major efforts are ongoing to innovate their aerodynamic design. In particular, train shape
The aim of the conference was to inform about the most recent methodologies for virtual prototyping and simulations. From 19th to 21st October, the Stuttgart International Congress Center hosted engineers and researchers from industry, research and education institutions, who shared best practices and recent outcomes from their simulation projects. The 29th ANSYS Users' Meeting started with a welcome speech by Jim Chashman (ANSYS CEO). The conference this year hosted over 1000 attendees, 200 technical presentations from Industrial Companies and Universities and 27 Technical Seminars. Thanks to the wide exhibition area available, the conference also gave the opportunity to engineers and ANSYS partners of a fruitful exchange of ideas. In addition to the more established engineering applications -like structural-mechanics, fluid-dynamics, electrical mechanics, a number of lectures and seminars focused on Engineering Systems Simulation and Optimization have been performed. Today, Engineering Systems like Car Engines, can be holistically simulated, accounting the physical and behavioral interactions between the subsystem parts. In the spirit of the conference, EnginSoft GmbH presented and time-lined an aerodynamic shape optimization process, presenting the paper “High Speed Train Aerodynamic Shape Optimization Methodology and Framework Comparison” [T. Newill - G. Buccilli, EnginSoft GmbH]. Train speed and aerodynamics efficiency are two concepts
contributes substantially to the overall aerodynamic performances. Typically, a 3D train design should guarantee an improved ratio between aerodynamic lift force and drag force with respect to reference designs. To pursue the High Speed Train aerodynamic optimization, EnginSoft GmbH proposed a methodology which used a baseline mesh model of the Train and a set of mesh-morphing control points. Then, instead of re-CADing and re-MESHing, the model was morphed using Arbitrary Shape Deformation algorithms. Finally, Latin Hypercube methods have been used to generate the Design Of Experiments and to identify the optimal Train Shape. To mesh-morph the Train model, EnginSoft GmbH used Sculptor™ software. Sculptor™ directly modifies any geometry or any mesh model, without using CAD or meshing tools. The software enables CFD analyses of different geometries in short time, without re-generating CAD geometries and meshes. This means that more design variations can be calculated in the same amount of time. Sculptor™ proved to be useful to find optimal High Speed
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Train design easier and quicker. Coupled with ANSYS-FLUENT, it allowed finding an improved train shape in just a few days, while with the traditional re-CAD and re-MESH approach, it would have taken several weeks. With subtle shape modifications, a sound 2% increase of overall lift/drag ratio and over 80% simulation time reduction was achieved – without affecting the overall geometry constraints. Sculptor™ avoided time consuming operations on the CAD model and on the computational grid, since the morphing took place over the ANSYS-FLUENT model directly. Besides the Train Aerodynamics optimization paper, at the 29th ANSYS Conference EnginSoft held a Seminar on “Product Design Chain Innovation thorugh Manufacturing Process Simulation” [N. Gramegna - Enginsoft Italy]. Today the whole product development chain can be simulated, from manufacturing process to thermalmechanical fatigue behavior and several CAE software are available for that purpose. More in particularly, the design of the manufacturing process (like casting, forging and machining) is gaining importance in product development, as all those processes directly impact mechanical properties and component behavior.
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During the seminar, EnginSoft presented innovative methodologies for Manufacturing Process simulation, all aimed at reducing product development time and resources needed. Nicola Gramegna gave the attendees an overview of the most relevant manufacturing processes, like Casting Process and Heat Treatment (simulated with the software MAGMASOFT), Forging (simulated with FORGE software) and Machining (simulated by the means of Advantedge software tools). Nicola showed how residual stresses-strains and local mechanical properties can be calculated through computer simulation. Finally, he showed how the non-uniform stressstrain and mechanical properties previously calculated, can be integrated into the FEM model (like ANSYS) to simulate the macro component behavior. For more information on Sculptor™: Giorgio Buccilli, EnginSoft GmbH [email protected]
SCULPTOR Sculptor is a powerful tool that allows a user to parameterize any mesh based on arbitrary cubic bezier control points. It can be linked to your existing fluid-flow (CFD) and/or structural (FEA) analysis tools and then deform these meshes and maintain quality in real time. Enabling the user to optimize a product without the need to remesh, saving you days, weeks, even months.
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BENIMPACT Suite has landed in China Dal 19 al 26 ottobre si è tenuto a Dalian, in Cina, il primo summit planetario sul basso impatto ambientale - Low Carbon Earth Summit (LCES 2011), che ha riunito esponenti della politica, della ricerca, delle tecnologie e pubblico con l’obiettivo di creare un tavolo intorno al quale scambiarsi le conoscenze oggi disponibili per riuscire a controllare l’impatto sul clima: “Spronare la green Economy per tornare in armonia con la natura”. Al “Forum 8: Clean Sciences and Technology for Low Carbon Environment - Today’s R & D, Tomorrow Industrial Revolutionization” di questo importante incontro è stato presentato anche il progetto CASA ZERO ENERGY, un edificio progettato e realizzato con un approccio “filosofico” che mira ad una visione integrata della sostenibilità. L’edificio, progettato dall’Università di Trento, è stato realizzato dal Gruppo Polo Le Ville Plus con il supporto della Regione Friuli Venezia Giulia. Numerose analisi di simulazione e ottimizzazione delle prestazioni energetiche ed ambientali sono state eseguite da EnginSoft con l’ausilio di BENIMPACT Suite. Portavoce dell’attività è stato il prof. Antonio Frattari, Responsabile Laboratorio Progettazione Edilizia (LPE) Direttore del CUnEd dell’Università di Trento. BENIMPACT Suite è il risultato di un progetto di ricerca cofinanziato dalla Provincia Autonoma di Trento - Legge Provinciale n° 6/99 Programma Operativo FESR 2007-2013 Obiettivo 2.
Last month, from 19th to 26th the first Low Carbon Earth Summit (LCES 2011) was held in Dalian, China. It brought together important politicians, researchers, and a large audience. The aim of this meeting was to create a round table where people could share their knowledge about controlling the environmental impact: “Leading the Green Economy, Returning to Harmony with Nature”. Prof. Antonio Frattari, the chief of Building Design Lab of the University of Trento, presented the project ZERO ENERGY HOUSE at “Forum 8: Clean Sciences and Technology for Low Carbon Environment - Today’s R & D, Tomorrow Industrial Revolutionization”. A philosophical approach towards integrate sustainability characterizes this building. The University of Trento has designed this house, Gruppo Polo Le Ville Plus has built it, and the local administration, Regione Friuli Venezia Giulia, has given its support. For the simulation of the building behavior BENIMPACT Suite has been used. BENIMPACT Suite is the outcome of a research project cofounded by the Autonomous Province of Trento (Italy) – Provincial Law n° 6/99 Operative Program FESR 2007-2013 Objective 2.
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CasaZeroEnergy can be called in this way because it has a very low energy consumption, it does not use any fossil fuels, and its energy demand is produced using renewable energetic sources. It anticipates the EU directive 31/2010/CE that requires the realization of near zero energy buildings, starting from 2020. The main features of CasaZeroEnergy are: • a strong bioclimatic characterization; • the use of natural, renewable and recycled materials for the construction of the building; • the development of a new and innovative timber frame system; • the set up of an intelligent system (home automation) to manage the energy consumption; • the integration with energy systems that use alternative and clean sources: photovoltaic plant of 14.6 kWh, solar thermal panels for DHW, horizontal geothermal plant with water – air heat pump integrated with a radiant floor heating and it can also work as a cooling system in summer. The building behavior has been simulated using BENIMPACT Suite and then compared with the real house behavior, which is monitored. Comparing the simulation with the monitoring results it is possible to observe some interesting things: • the performed simulation (with only two thermal zones) has been validated with the monitoring; • the building behavior is very good and it meets in a perfect way the expected predictions for summer. except from some temperature picks in the hottest days (June 29th and July 4th) the comfort in the house has been always achieved in the monitored period.
Alta Formazione: TCN punta ad una specializzazione sempre più avanzata Anche per l’anno 2012 il Consorzio TCN erogherà corsi di formazione specialistici e corsi a calendario. Continuerà l’attività di organizzare corsi personalizzati a seguito di specifiche richieste da parte dell’industria. A questi si aggiungeranno una serie di Minimaster con programmi formativi più intensi ed approfonditi rispetto a quelli dei corsi base ed avanzati. Per questo nuovo anno c’è anche l’intenzione di inserire corsi che trattano argomenti inediti di attuale interesse. Tutto sarà coordinato tra il Consorzio TCN ed i responsabili della formazione delle varie realtà lavorative. Per informazioni vi consigliamo di visitare il sito: www.consorziotcn.it oppure contattare la segreteria organizzativa: Mirella Prestini [email protected]
For more information: Angelo Messina, EnginSoft [email protected]
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CAE Seminars in Japan “CAE UNIVERSITY” Cybernet Systems Co.,Ltd. (with its headquarter located in Tokyo) has offered a wide range of leading-edge CAE solutions and services for many years since its establishment in 1985. Today, Cybernet sells more than 80 CAE products for diverse applications in mechanical, electrical and control engineering, optics, civil engineering and construction, optimization, bioengineering, nanotechnology and other sectors. To complement its software portfolio for its clients across Japan, Cybernet provides different types of services, such as technical support, training, and consultancy, to companies in manufacturing, as well as to universities and research institutes…and far more than this: The engineers of Cybernet are passionate about supporting MONOZUKURI in Japan, as one of the country’s leading CAE providers. The company’s corporate message states: “Energy for your Innovation”. To foster the interest in CAE and to support the next generation of CAE engineers, Cybernet developed and introduced an educational system called “CAE UNIVERSITY”. CAE University’s primary objective is to grow the use of CAE techniques among engineers. In Japan, the use of CAE technologies in manufacturing has expanded significantly in recent years. While we witness a growing interest in CAE, we also hear that many companies ask for additional support and know-how for improving their application skills and for making the use of CAE more efficient to solve their real problems. CAE UNIVERSITY is a new type of educational system which enables students to learn CAE systematically and continuously. It provides students with the necessary skills to use CAE technologies flexibly and efficiently for the actual requirements in their product design and development activities. Lectures and practical examples CAE UNIVERSITY offers both, 1-day or 2-day courses, in short periods, on each single topic in different fields. In lectures and hands-on sessions, participants study intensively theories of mathematics, physics and engineering, which are used in CAE today. By combining different courses, they are able to acquire theoretical knowledge in each field systematically. For example, by attending the 1.5 day lecture on
“Design and CAE Mechanics through Numerical Experiments“, the students learn many applications, from the basic numerical experiment and its theoretical consideration using beam and frame structure, to the modeling of solid structures, thermal stress and anisotropic materials. FEM Laboratory Nowadays, performing simulation by using CAE has become quite common in design and development departments. However, engineers sometimes are facing problems when simulation results differ from testing results. By performing testing and by comparing test results with simulation results in the FEM Laboratory, students can study and discuss the factors which sometimes lead to such errors. This helps them to understand the background and how the different steps and techniques are linked; they can now evaluate and verify simulation results correctly and make efficient use of them in their real design and development work. I had a pleasure to conduct the following interview with Mr. Takashi Sakurai, Manager of CAE UNIVERSITY. Please can you tell us about the positioning and the features of CAE UNIVERSITY? The main features of CAE UNIVERSITY are to offer the curriculum, which meets certain standards based on the University’s educational system and to invite active teachers from universities. The courses are linked with each other and the learning content has been examined carefully to avoid overlapping and insufficiency. Teachers who are in charge of the computational mechanics courses get together for
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curriculum meetings periodically, to check and modify the interaction of each lecture and practice. CAE UNIVERSITY can be regarded as a new CAE education system with a universitylike philosophy that offers high CAE knowledge levels. Concerning the content, some may think that mostly advanced CAE theory is being taught. The aim of CAE UNIVERSITY though clearly is not limited to the teaching of theory, it also provides the knowledge of advanced techniques of how to use CAE in the right way. Hence the theory is just an element of the teaching content. We believe that a combination of both: learning how to apply CAE and studying theory, will enable us to use CAE effectively for the actual job. Many companies have learned in the meantime that CAE is not a magical tool that will help just by introducing it. Introducing CAE also requires learning methods for its correct use. CAE UNIVERSITY is a reasonable system to learn techniques for CAE usage because it is systematic and continuous.
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about them. This means touching and trying shapes their imagination and deepens their understanding. Therefore, the “FEM Laboratory”, which offers a combination of lectures and testing is very effective. FEM Laboratory maintains a high reputation and gathers many registrations always. The size of testing is not so large, because it needs to be done on the desk. However, the testing is very well conducted and sufficient to understand the essence. Presently, we offer 2 FEM Laboratory courses, we are planning to add more in the future. Attending these courses, in which the students perform testing in groups, also provides a good platform for them to share information and to get to know each other and each other’s work easily. Often, students from different companies keep in touch afterwards and discuss their own problems with other engineers in similar environments.
What type of students do you have mostly? Many different types of employees participate. We welcome designers, R&D engineers, analysis specialists and trainers. We have students from universities too. They usually have different goals, for example reviewing things they have learned many years ago and solving specific problems on the job. We ask everybody who registers to complete a questionnaire before the course; we ask to tell us about requests, expectations and backgrounds. Teachers prepare and try to arrange the course as much as possible following the students’ satisfaction questionnaires. There is another questionnaire that is submitted after each course for future improvement of the courses. With these efforts, we are able to maintain good quality and to constantly gain reputation. The number of students who register for subsequent courses is rather high. Recently, we received several requests to hold on-site CAE UNIVERSITYs from customers who greatly appreciate the philosophy and the intent. Our clients more often book now on-site Courses and arrange for their engineers to participate in the entire range of lectures and practical sessions over months, to provide thorough CAE employee training.
Please tell us about your future vision for the “CAE UNIVERSITY” Currently, students need to come to our seminar room to attend CAE UNIVERSITY. This is difficult for someone who has to travel a long way or for those whose schedules are tight. To improve this, we are planning an alternative way of CAE education. Actually, we already have experiences in delivering the customized CAE UNIVERSITY on the customer’s intranet so that all their engineers can learn while being at work. By using cloud computing, the system can be applied and extended to a wider area and audience. We can indeed offer CAE UNIVERSITY to many more people. Also, if we develop other language versions, it will be possible to share this education system globally. We want to achieve new CAE oriented design innovation by collaborating with as many engineers as possible who have studied and overcome engineering challenges. To reach this goal, we want to build a CAE community, to foster comprehensive CAE development in Japan and in other countries around the world. This is our ultimate vision and goal.
What is the students’ general reaction to the “FEM Laboratory”? CAE is a tool for design. Designers have got into the habit of doing, looking at and touching real things and thinking
This article has been written in collaboration with CYBERNET SYSTEMS Co.,LTD.: http://www.cybernet.co.jp/english/ Akiko Kondoh, Consultant for EnginSoft in Japan
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NPO Activity for Implementation of Anisotropic Elasto-plastic Models into Commercial FEM Codes The nonprofit organization JANCAE, The Japan Association for Nonlinear CAE (chairperson: Kenjiro Terada, Tohoku University), offers several activities to companies, universities and software vendors [1] to gain a deeper understanding of nonlinear CAE including its main work, the nonlinear CAE training course held twice a year. This article introduces JANCAE’s efforts to implement anisotropic elasto-plastic models into commercial FEM codes as one of the initiatives of the “Material Modeling Committee”. 2. Background and outline 2.1 The efforts of the Material Modeling Committee: When we think of comprehensive advancements in the accuracy of a simulation, we are aware that all capabilities of the material modeling, the boundary conditions as well as the definition of the geometric modeling have to be improved at the same level. The capabilities of geometric modeling for FEM simulations have drastically improved along with the growth of the 3D CAD market, the advancements in auto-meshing capabilities and the progresses made in hardware speeds and capacities, over the past 10 years. Yet material modeling capabilities have not progressed as significantly as the advances achieved in geometric modeling. Users need to be involved in the definition process of material modeling, which means that they have to choose the appropriate material model from huge amounts of available material models offered by each FEM code. As a next step, the parameters of the material properties have to be determined by performing material tests. These processes are still necessary, even now, at a time when many sophisticated commercial FEM codes are available. In this situation and independently from its CAE training course, which mainly consists of classroom lectures, JANCAE organizes “The Material Modeling Committee” as a practical approach to the study of nonlinear materials. The Committee was originally established in 2005 to study mainly hyperelasticity and viscoelasticity. Then, its research activities have diversified into all material nonlinearity including metal plasticity. In the frame of the Committee, members learn about typical nonlinear material modeling by studying the basic theory of the constitutive equations, material testing methods, and how to handle test data and parameter identification techniques. 2.2 User subroutines for constitutive law in FEM Codes There are many constitutive equations of materials, as we can see from the many researchers’ names which appear in the titles of the equations. Although such variety of material models contributes to the improvement of simulation accuracy, not all material models, especially new models, can be applied
to various commercial FEM codes. With regard to yield functions, which are a core concept for metal plasticity, it has been pointed out that the yield surfaces of the actual metal materials cannot be represented well enough by the classical anisotropic yield functions [2]. However now, many different types of new yield functions are proposed especially in sheet metal forming; they are able to represent real plastic deformation much better than before [3]. LS-DYNA provides specific capabilities for sheet metal forming simulation, it also offers a considerable number of new anisotropic yield functions [4]. On the other hand, when we think about other commercial general purpose FEM codes, they usually have only limited kinds of yield functions, such as the classical Hill quadratic anisotropic function. These commercial codes offer user subroutine capabilities to extend material models. By using these capabilities and defining material models following the programming rules that each code provides, users can implement the required constitutive laws. However in reality, it is difficult for ordinary users who are not familiar with the framework of continuum mechanics, numerical simulation and the theory of plasticity, to perform such processes only from released text books or available information, as the manual definition in FEM codes requires professional skills. 2.3 The development activity in the Material Modeling Committee The Material Modeling Committee started its unique R&D activity in 2009. For this activity, engineers with various backgrounds and skills engaged in the CAE field got together to jointly work on making subroutines for the constitutive laws. The members are from industrial companies and CAE software vendors. As mentioned above, it is impossible to create such subroutines without understanding the basic concept of elastoplastic models for FEM. In the first year, in 2009, we studied the basics of plastic constitutive equations and the framework
Fig. 1 - Framework of the subroutine “UMMDp”
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of constitutive law subroutines by referring to some text books [5], to obtain a better understanding of their principles. In parallel, we summarized the characteristics of each code’s user subroutine and proposed a framework for the user subroutine development. [Fig.1] In this framework, stress integration and calculation of consistent tangent modulus, which represent basic capabilities of constitutive law subroutines, have been determined as “Unified Material Model Driver for Plasticity (UMMDp)” and separated from each code’s specified rule in order to be able to be used commonly. Additionally, yield functions were isolated as a modularized subroutine so that we can implement different types of yield functions easily. In the second year, in 2010, the members worked on the programming based on this framework and by sharing each role. 3. Development and verification of the user subroutine 3.1 Basic equations of elasto-plastic constitutive laws Here we show the basic part of the subroutine for elasto-plastic constitutive laws, which is crucial for this programming. Tensor is represented by the Voigt notation arraying components as vector. The stress to be calculated is , and the strain increment given to the subroutine is . Following are basic equations for elasto-plastic constitutive laws. (1) (2) (3) (4) (5)
Equation (1) shows the yield condition and represents that stress point on the yield surface. The shape of the yield surface is determined by the yield function , the magnitude is given by the hardening curve showing isotropic hardening and the center of the yield surface is provided by the back stress showing kinematic hardening respectively. Equation (2) shows that the elastic and the plastic strain increments are given by additive decomposition, and the elastic strain increment gives the stress increment by Hooke’s law shown as Equation (3). Equation (4) gives the plastic strain increment and here the associated flow rule is used, in which the outward normal of the yield surface and the plastic strain increment have the same direction. Equation (5) is the evolution equation of the back stress. p shows the equivalent plastic strain which has a conjugate relation with the equivalent stress in the plastic work. UMMDp uses backward Euler’s method for the stress integration algorithm. In this method, nonlinear simultaneous equation is solved, assuming the stress and internal variable (back stress and equivalent plastic strain pn+1) after the completion of ”n+1” increment satisfy the basic equations (1) – (5). We now define residual functions as follows. (6) (7) (8)
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Now is the trial stress (initial estimate of stress integration) assuming all strain increments are elastic components and given by
Equation (6), Equation (7) and Equation (8) correspond to the yield condition of Equation (1), Equation (2) – (4) and the back stress evolution equation of Equation (5) respectively, and the stress after integration and the internal variable ( and ) are obtained by converging , and to 0 using Newton-Raphson method. In UMMDp, it is predicted that the convergence calculation will be difficult because of implementation of higher order anisotropic yield functions. So we relaxed the condition of (6) by using Multistage Return Mapping [6] which leads to gradual convergence. 3.2 The idea of UMMDp The variables used for convergence calculation of the stress integration are the yield function , the isotropic hardening curve , the back stress evolution equation and their first and second order differentials. In the static implicit method, tangent matrix (Material Jacobian) consistent with stress integration algorithm, is also required to obtain the quadratic convergence in equilibrium calculation. In this calculation, as with the stress integration, yield function, isotropic hardening curve, back stress evolution equation value and its differential value are going to be needed. The frameworks of calculation for stress integration and consistent tangent modules are in common regardless of forms of yield function, hardening curve and back stress evolution equation. Therefore, if we could make a unified interface for those various sets of functions, the function group of a variety of constitutive equations described above would be able to be modularized and have higher expandability. When we think about the variable names and the stored formats in subroutines of commercial codes, of course they vary from code to code. However, the role of the constitutive law in FEM codes is to provide “local stress-strain relation at integration point” and there is no difference on this point. By using proper variable conversion for code-independent user subroutines, they can be linked to UMMDp correctly. From this standpoint, the great variety of constitutive equations, such as yield function and hardening law can be externalized. Additionally, if we develop the interface for different commercial codes using their specific user subroutines, which we call “Plug”, it will kick-off an open effort and a discussion which will not be limited to a specific code. 3.3 Yield function subroutine The yield function subroutine is developed mainly by CAE users from industrial companies. Following are the yield functions for the implementation. (von Mises is used for verification of the implementation.) von Mises[7] Hill(1948[8], 1990[9])
48 - Newsletter EnginSoft Year 8 n°4 Gotoh's bi-quadratic yield function [10] Barlat yield function (Yld89[11], Yld2000[12], Yld2004[13]) Banabic yield function (BBC2005[14], BBC2008[15]) Cazacu 2006[16] Karafills & Boyce[17] Vegter[18] The yield function subroutine receives the stress component as the argument, and then returns the corresponding equivalent stress , its first order differential and its second order differential . To demonstrate objectively that the developed subroutine works correctly, also numerical verification is being performed. For this verification, we also provide a main routine so that only the capability of the yield function’s subroutine itself can be checked separately without mixing up its bug with other bugs in UMMDp (the parent routine of the yield function’s subroutine), and “Plug” for commercial FEM codes. By doing so, the members can work independently. The verification was performed by the comparison between the yield surface in the original paper, which proposed anisotropic yield functions, and the output from our developed subroutine as shown in Fig.2, as well as by the comparison between analytical and numerical differential values to secure correctness. 3.4 Development of the interface “Plug” for commercial codes The “Plug” subroutine, which becomes an interface to commercial FEM codes, is developed mainly by engineers from CAE software vendors. This subroutine links to UMMDp correctly through each different manner depending on commercial codes. The name of the ‘Plug’ is based on the functional analogy of plug-adopter for AC power socket which differs by nation. The Plug needs to offer overall capabilities for communication with commercial codes, such as storing and updating internal variables, and variable output adjustment to result data. On this point, it was very helpful to gain the cooperation of engineers from software vendors, who are familiar with each commercial code. We appreciated their cross-border cooperation. The verification of the developed Plug was also performed. For this verification, we used the basic benchmark test provided by the NAFEMS guidebook [19] for “Code to Code Verification”. We
(a) Yield locus in original paper [12]
(b) Output from ummdp_checkyf
Fig. 2 - Verification of yield function subroutine (eg:Yld2000).
compared the result using default elasto-plastic models prepared in each commercial code (von Mises type isotropic yield functions) and the result using the von Mises type yield function through UMMDp, and we confirmed that these stress histories are matching as shown in Fig.3.
Fig. 3 - Comparison with result of commercial code (von Mises model)
3.5 Implementation of combined hardening law We finalized the development and the verification of the program for the standard isotropic hardening models in 2009. It is difficult to simulate deformation behavior accurately when the direction of stress is reversed. So we are promoting the development of the combined hardening model including kinematic hardening shown in the basic equations. Kinematic hardening behavior is modeled by back stress evolution equation. For this evolution equation, various types of models are proposed, and we need to accept this diversity as with yield functions. At this point in time, we are developing a framework to modularize the function shown in Equation (5) as a subroutine. 3.6 Total verification For total verification of the developed program, we analyzed problems which come to the surface by the influence of plastic anisotropy, and we compared them to the reliable result. We simulated a hole-expansion test of a steel sheet [20] and a hydraulic bulge test of aluminum alloy [21] in cooperation with Prof. Kuwabara, Tokyo University of Agriculture and Technology. Fig.4 shows the simulation result of the holeexpansion test. We can see that the thickness decrease around the center hole varies with angle from the rolling Fig. 4 - Simulation example of holeexpansion test direction. Afterwards, we verified that the developed subroutine group worked rightly, by comparing the UMMDp simulation result and the reliable simulation result. The aim of the verification at this stage is not the comparison with experimental results, instead it is absolutely for Code to Code Verification. We think that using the middle scale problem, which is positioned between small scale problems like material testing and large scale problems in realistic sheet metal forming, is more important for the material model validation rather than jumping to a complicated large scale problem. 4. Closing In this article, we introduced an activity of the NPO “JANCAE” working group. As the volume of tasks becomes larger, the development is still in progress. In 2011, the development of a common subroutine for resin and rubber has been planned as a subsequent activity of the working group. The effort this
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time is the implementation of the yield functions which were already proposed in previous papers, hence there is no academic novelty. Meanwhile, it is not just about a limited activity for a specific commercial code only. This is why the topic is not really suitable to be presented in academic societies or at specific users’ conferences by CAE vendors. We introduced this work as an example of the activities featuring NPO’s neutrality. Following NPO’s guidelines, it is planned that the subroutine group will be opened to the public a year after activity completion. Yet more than 30 engineers from different organizations have already joined the working group. Their backgrounds are different, some have already obtained permissions from their managers, some join to support their own personal development. In any case, their motivation is the most important driving force for the activity. C.A Coulomb, when he was a building engineer in the military corps of engineers, expressed the reason to write a paper by making an analogy to an artisan when he submitted the paper to the French Académie des sciences in 1773, as follows.[22] “Besides, the Sciences are monuments consecrated to the public good. Each citizen ought to contribute to them according to his talents…. While great men will be carried to the top of the edifice where they can mark out and construct the upper stories, ordinary artisans who are scattered through the lower stories or hidden in the obscurity of the foundations should seek only to perfect that which cleverer hands have created.” We think the reason why so many engineers were eager to be involved in the work is because of their motivation to understand in a deeper way and to express their sympathy for the activity based on Coulomb’s words. We, ordinary artisans, have great responsibility in the present apprehensions regarding the gap between computational mechanics and CAE [23]. 5. References [1] http://www.jancae.org/ [2] The Japan Society for Technology of Plasticity ed.: StaticImplicit FEM – Sheet metal forming (process simulation series), Corona Publishing, pp.198, 2004. (in Japanese) [3] ibid. pp.172. [4] LSTC, JSOL: LS-DYNA Version 970 User’s Manual Vol.2, 2003. [5] F.Dunne, et al.: Introduction to Computational Plasticity, Oxford Univ. Pr., 2005. [6] J.W.Yoon, et al.: Elasto-plastic finite element method based on incremental deformation theory and continuum based shell elements for planar anisotropic sheet materials, Comp. Meth. Appl. Mech. Engrg., vol.174, pp.23-56, 1999. [7] R.von Mises: Mechanik der festen Körper in plastischendeformablem Zustand, Göttinger Nachrichten math.-phys. Klasse, pp.582, 1913. [8] R.Hill: A theory of the yielding and plastic flow of anisotropic metals, Proc. Roy. Soc. A: vol.193, pp.281, 1948. [9] R.Hill: Constitutive modeling of orthotropic plasticity in sheet metals, J. Mech. Phys. Solids, vol.38, no.3, pp405417, 1990.
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[10] M.Gotoh: Improvement of orthotropic theory by implementation of forth order yield function (plane stress) I, JSTP journal, vol.19, no.205, pp.377-385, 1978. [11] F.Barlat, et al.: Plastic behavior and stretchability of sheet metals. Part-I, Int. J. Plasticity, vol.5, pp.51-66, 1989. [12] F.Barlat, et al.: Plane stress yield function for aluminum alloy sheet: part 1:theory, Int. J. Plasticity, vol.19, pp.1297-1319, 2003. [13] F.Barlat, et al.: Linear transformation-based anisotropic yield functions, Int. J. Plasticity, vol.21, pp.1009-1039, 2003. [14] D.Banabic, et al.: Influence of constitutive equations on the accuracy of prediction in sheet metal forming simulation, Proc. of NUMISHEET2008, 2008. [15] D.Banabic, et al.: Plane-stress yield criterion for highlyanisotropic sheet metals, Proc. of NUMISHEET2008, 2008. [16] O.Cazacu, et al.: Orthotropic yield criterion for hexagonal closed packed metals, Int. J. Plasticity, vol.22, pp.11711194, 2006. [17] A.P.Karafillis, M.C.Boyce: A general anisotropic yield criterion using bound and a transformation weighting tensor, J. Mech. Phys. Solids, vol.41, no.12, pp.18591889, 1993. [18] H.Vegter, et al.: A plane stress yield function for anisotropic sheet material by interpolation of biaxial stress states, Int. J. Plasticity, vol.22, pp.557-580, 2006. [19] A.A.Becker: Understanding Non-linear Finite Element Analysis Through Illustrative Benchmarks, NAFEMS, pp.20, 2001. [20] Kuwabara, T., Hashimoto, K. Iizuka, E. and Yoon J.W., Effect of anisotropic yield functions on the accuracy of hole expansion simulations, J. Mater. Processing Technol., 211 (2011), 475-481. [21] Daisaku Yanaga, Toshihiko Kuwabara, Naoyuki Uema and Mineo Asano: Material Modeling of 6000 Series Aluminum Alloy Sheets with Different Density Cube Textures and Effect on the Accuracy of Finite Element Simulation, Proc. NUMISHEET 2011, Seoul, Korea, 21-26 August, 2011, pp.800-806. (AIP Conference Proceedings, Volume 1383) [22] Timoshenko, S.P.: History of Strength of Materials, Dover publications, pp.47, 1983. [23] N.Kikuchi: Computational Solid Mechanics –Trend and Future, JSCES Journal, vol.11, no.1, pp.1290-1295, 2006. (in Japanese) Hideo Takizawa (Mitsubishi Materials Co, Japan) Vice-chairman of JANCAE Material Modeling Committee For more information about this article, please e-mail: [email protected]
By courtesy of Mechanical Design & Analysis Corporation, an original version of this article was presented at the 4th Mech D&A Users’ Conference, 1 July 2011 (Tokyo, Japan) and published in the Conference Proceedings.
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EnginSoft Event Calendar ITALY For more information on the next EnginSoft Seminars and Webinars, please contact: [email protected] Stay tuned to: www.enginsoft.com (Events) Download the 2011 Conference Proceedings now on: www.enginsoft.com/proceedings2011 and stay tuned for the dates/venue of the 2012 International Conference: www.caeconference.com Every year, the conference program features applications of CAE in: mechanics, industrial applications, structural engineering, optimization, manufacturing process simulation, computational fluid dynamics, emerging technologies, durability and fatigue, rapid and impact dynamics, CAD/CAE integration, … 9-10 February - High Tech Die Casting, Vicenza EnginSoft will present a case history of the process simulation applied to Ferrioli radiators. www.metallurgia-italiana.net 18-21 April - METEF 2012, Fiera Verona EnginSoft will present the MAGMA 5.2 release. www.metef.com 15th European Conference on Composite Materials. 24-28 Giugno; Venezia. www.eccm15.org. 3rd Dolomites Workshop on Constructive Approximation and Applications; 9-14 Settembre; Canazei events.math.unipd.it/dwcaa2012/?q=node/1 GERMANY 15-16 November - NAFEMS European Conference: Simulation Process and Data Management (SDM). Munich If you would like to hear more about EnginSoft Germany’s presentation on: Methodology and Validation for Bidirectional, Homogeneous Simulation Data Flow Management in a Fluid-Structure Interaction Problem Utilizing Workflow Management and Shape Deformation Tools, please contact our team at: [email protected] EnginSoft Germany. Regular Webinars and On-site Presentations 2011 & 2012: EnginSoft Germany hosts regular Webinars to present the company’s products and services, as well as specific Webinars to discuss our customers’ current applications and needs. To hear more and to fix an appointment for your company,
please contact: [email protected] Please stay tuned to: http://www.enginsoft-de.com/ FRANCE Flowmaster Roadshow 2012 Pour accompagner le lancement de Flowmaster V7.9 et présenter ses principales nouveautés, Enginsoft France organise des conférences dans plusieurs villes de France. Vous y découvrirez notamment l’analyse diphasique, le temps réel, et le couplage avec modeFRONTIER. Inscrivez-vous vite! Book your place now, for the Conferences that EnginSoft France will host in 2012 – Hear about Flowmaster V7.9 and the coupling with modeFRONTIER! Voici les lieux et dates – Dates & venues: • 2 février 2012 après midi à Nantes • 7 février 2012 après midi à Lyon • 9 février 2012 après midi à Toulouse • 14 février 2012 après midi à Aix en Provence • 16 février 2012 après midi à Paris Pour vous inscrire, appelez vite le +33 (0)1.41.22.99.30 ou visitez http://www.enginsoft-fr.com/ EnginSoft France 2011 & 2012 Journées porte ouverte dans nos locaux à Paris et dans d’autres villes de France, en collaboration avec nos partenaires. Pour plus d'information visitez: www.enginsoft-fr.com, contactez: [email protected] UK The workshops are designed to give delegates a good appreciation of the functionality, application and benefits of modeFRONTIER. The workshops include an informal blend of presentation plus ‘hands-on’ examples with the objective of enabling delegates to be confident to evaluate modeFRONTIER for their applications using a trial license at no cost. modeFRONTIER Workshops Warwick Digital Laboratory, Warwick University • Thursday 10th March • Tuesday 12th April • Tuesday 21st June • Wednesday 17th August • Tuesday 1st November • Wednesday 14th December modeFRONTIER Workshops at Warwick Digital Laboratory, Warwick University
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Thursday 10th March Tuesday 12th April Tuesday 21st June Wednesday 17th August Tuesday 1st November Wednesday 14th December
modeFRONTIER Workshops at Cranfield University • Thursday 27th May modeFRONTIER Workshops for InfoWorks CS at Warwick Digital Lab • Tuesday, 8th February • Thursday 26th May • Wednesday 20th July • Thursday 13th October • Tuesday 22nd November To register, please visit: www.enginsoft-uk.com 7th December - CIWEM Innovations Showcase, Coventry EnginSoft has been selected to present 'Exploring the full range of possible solutions to DG5 schemes by combining modeFRONTIER's smart algorithms with InfoWorks CS maximising customer choice between performance and cost' http://bit.ly/InnSC SWEDEN 2011 Training Courses on modeFRONTIER – Drive your designs from good to GREAT EnginSoft Nordic office in Lund, Sweden The Training Courses are focused on optimization, both multi- and single-objective, process automation and interpretation of results. Participants will learn different optimization strategies in order to complete a project within a specified time and simulation budget. Other topics, such as design of experiments, meta modeling and robust design are introduced as well. The two day training consists of a mix of theoretical sessions and workshops. The following dates are scheduled for 2012. All courses are held at the EnginSoft Nordic office in Lund, Sweden. • 1st-2nd December • 25-26th January • 8th-9th February • 6th-7th March • 2nd-3rd April • 3rd-4th May • 5th-6th June • 4th-5th September • 3rd-4th October • 6th-7th November • 6th-7th December To discuss your needs, for more information and to register, please contact EnginSoft Nordic, [email protected]
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SPAIN EnginSoft Iberia. Programa de cursos de modeFRONTIER and other local events. To enquire about the next events in Spain and for more information, please contact: tel: +34 938.945.092. email: [email protected] Stay tuned to: http://iberia.enginsoft.com/empresa El 14 de diciembre de 2011 a las 09:30 Webcast: Add-On para LabVIEW de modeFRONTIER para la Optimización de parámetros y Prototipado Rápido de Control El 20 de diciembre de 2011 a las 10:00 (45 minutos) Webcast: Metodologías que aumentan su valor añadido a sus clientes For more information on the 2 Webcasts, please visit: http://www.aperiotec.es/agenda.php USA TMS 2012 Annual Meeting & Exhibition; 11-15 March; Orlando. www.tms.org/meetings/annual-12/AM12home.aspx Courses and Webinars on Design Optimization with modeFRONTIER Sunnyvale, CA. For more information, please contact: [email protected] www.ozeninc.com ISRAEL AUVSI; 20-22 Marzo; Tel Aviv event.pwizard.com/auvsi2012/index.py?p=376 EUROPE, VARIOUS LOCATIONS modeFRONTIER Academic Training Please note: These Courses are for Academic users only. The Courses provide Academic Specialists with the fastest route to being fully proficient and productive in the use of modeFRONTIER for their research activities. The courses combine modeFRONTIER Fundamentals and Advanced Optimization Techniques. For more information please contact: modeFRONTIER University Program, [email protected] To meet with EnginSoft at any of the above events, please contact us: [email protected]
Corsi di addestramento software 2012 L'attività di formazione rappresenta da sempre uno dei tre maggiori obiettivi di EnginSoft accanto alla distribuzione ed assistenza del software ed ai servizi di consulenza e progettazione. Per ciascuno dei possibili livelli cui la richiesta di formazione può porsi (quella del progettista, dello specialista o del responsabile di progettazione), EnginSoft mette a disposizione la propria esperienza per accelerare i tempi del completo apprendimento degli strumenti necessari con una gamma completa di corsi differenziati sia per livello (di base o specialistico), che per profilo professionale dei destinatari (progettisti, neofiti od analisti esperti). La finalità è sempre di tipo pratico: condurre rapidamente all'utilizzo corretto del codice, sviluppando nell'utente la capacità di gestire analisi complesse attraverso l'uso consapevole del codice di calcolo. Per questo motivo ogni corso è diviso in sessioni dedicate alla presentazione degli argomenti teorici alternate a sessioni 'hands on', in cui i partecipanti sono invitati ad utilizzare attivamente il codice di calcolo eseguendo applicazioni guidate od abbozzando, con i suggerimenti del trainer, soluzioni per i problemi di proprio interesse e discutendone impostazioni e risultati. Anche per il 2012 EnginSoft propone una serie completa di corsi che coprono le necessità di formazione all'uso dei diversi software sostenuti. Le novità proposte, confermano l’idea che EnginSoft ha della formazione: non è una realtà statica che si ripropone uguale a se stessa di anno in anno, ma è un divenire, guidato dall'esperienza accumulata negli anni, dall'evoluzione del software e dalle esigenze delle società che si affidano a noi per la formazione del proprio personale. In tale contesto EnginSoft organizza e sviluppa anche attività didattiche attraverso un programma formativo personalizzato, soluzioni di progettati in relazione alle necessità e alle specifiche esigenze aziendali del committente. L’offerta dei corsi ANSYS viene ridefinita ogni anno per adeguarsi, sia all’evoluzione del software ed alle caratteristiche dell’ultima versione disponibile, che all’introduzione di nuovi moduli e solutori. In tale senso si segnala in campo fluidodinamico l'introduzione, accanto ai corsi tradizionalmente erogati, del corso ANSYS FLUENT: Corso Avanzato sulla Combustione. Sono stati inoltre rivisti ed aggiornati i corsi relativi a tutti gli altri software sostenuti da EnginSoft per adeguarli allo stato attuale delle relative distribuzioni.
Si segnala infine l'introduzione del nuovo corso DIGIMAT, modellatore avanzato, non lineare, multi-scala di materiali che si pone come obiettivo quello di offrire una rappresentazione completa e rigorosa utile sia ai fornitori di materiali (“progettisti” di materiali), sia ai progettisti analisti CAE (end users) per i quali, il più delle volte, il materiale viene modellato in modo semplificato. Dal punto di vista organizzativo nel 2012 tutte le sei sedi EnginSoft saranno impegnate nella formazione, dando la possibilità agli utenti di scegliere la location a loro più conveniente in termini di vicinanza geografica alla propria società. Tutto questo a riprova dell'impegno nella formazione che, per EnginSoft, è e rimane un punto fondamentale della politica aziendale, un impegno costante verso l'eccellenza, un servizio per fare crescere i suoi clienti e, se lo desiderano, crescere con loro. Per maggiori informazioni: www.enginsoft.it/corsi Per richiedere una copia del libretto: [email protected]
Multi-objective Optimization with modeFRONTIER Applied to Systems Biology
EnginSoft CAE Conference 2011 Welcomes an Audience of 600 CAE users EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca
Synergy between LS-DYNA and modeFRONTIER to Predict Low Velocity Impact Damage on a Composite Plate
Structural Optimization of a Car-body High Speed Train An Innovative Analysis and Design Methodology
Electromagnetic issues for a IEEE 1902.1 “RuBee” tag dipped in a fiber/composite laminate
FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis
Newsletter EnginSoft Year 8 n°4 -
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EnginSoft Flash CIRA, the Italian Aerospace Research Centre, For many of us, December is a time for illustrates the Synergy between LS-DYNA and reflection, for harvesting the fruit of our modeFRONTIER to predict low velocity work and our personal efforts of the year. impact damage on a composite plate. We Our Simulation and CAE environments hear from EnginSoft Nordic in Sweden on almost constantly see new developments, how multi-objective optimization is being upcoming software releases and changes. applied to systems biology. Here, we We are asked to be always ready for the encourage our readers to watch the movie “new”. While this is sometimes a challenge “Insulin Signaling (SignalPathways)” via the for most of us, every year also brings many link provided! new human encounters. In our fields of business, we can consider ourselves lucky We are pleased to introduce our customer to have the opportunity to meet people and ANSYS user the company Almacis, and from the CAE community, from around the AMD, our partner in the area of High world. While we learn about new and Ing. Stefano Odorizzi Performance Computing. different technologies, the human, the EnginSoft CEO and President Digimat is a powerful software for material engineer, its broad knowledge and modeling which is now distributed in Italy by experiences, always remain at the core of EnginSoft. More software news covers the LIONsolver by our attention. Reactive Research, NVIDIA’s Tesla GPU, EnginSoft’s By sharing our knowledge, especially on occasions such as activities for composite materials with ESAComp and the EnginSoft International Conference, we help to shape ANSYS Composite Prep/Post as well as MAGMA’s release the future path of CAE and to support the next generation 5.2. The powerful Sculptor tool allows users to of CAE engineers. parameterize any mesh based on arbitrary cubic bezier In this Newsletter, we speak about the EnginSoft and control points. Sculptor was recently presented by ANSYS Italian Conferences 2011, the two annual events EnginSoft GmbH at the ANSYS Conference and 29th that offer one of the major knowledge platforms to CAE CADFEM Users’ Meeting in Stuttgart. users in Europe and beyond. ANSYS is the provider of the world’s leading software for engineering simulation and Furthermore, we hear about Gruppo Ferroli’s project with EnginSoft’s number 1 partner. EnginSoft and ANSYS were EnginSoft, the recent introduction of the BENIMPACT delighted to welcome 600 delegates to Verona on 20th project in China and about the Minimaster and the and 21st October, to a wealth of topics on today’s use of Training Programs of TCN and EnginSoft. simulation and design tools. Our Japan Column tells us about the CAE University while In this issue, we also inform our readers about the Round some of the activities of JANCAE, The Japan Association Table Meeting of 100 Top Managers on the occasion of the for Nonlinear CAE, are explained to us in the article by opening of EnginSoft’s Research Center in the Scientific Hideo Takizawa. Technology Park ”Kilometro Rosso”. The use of ANSYS Please mark your diary for the modeFRONTIER Users' Maxwell v.14 is shown in the article on electromagnetic Meeting 2012, which will be sponsored by ESTECO and issues for a IEEE 1902.1 “RuBee” tag dipped in a take place on 21st and 22nd of May 2012 in Trieste. fiber/composite laminate. The capabilities of We hope that you enjoy reading the articles on the modeFRONTIER are described in AnsaldoBreda’s work for following pages of this last Newsletter of 2011. We always the structural optimization of a car-body high speed train. welcome your thoughts, your feedback as well as your Our readers also hear about the use of ANSYS AQWA and ideas for future publications! the ANSYS Workbench platform for the structural verification of the FSO Mooring System complemented by EnginSoft and the Editorial Team wish you and your EnginSoft’s broad experiences as a partner to the Oil&Gas families a very happy, healthy and a prosperous New Year industries. 2012! The Università degli Studi di Ferrara presents their work with ANSYS CFX 13.0 while University of Debrecen Hungary Stefano Odorizzi informs us of how Grapheur can help its users with multiple criteria decision- making problems. Editor in chief
4 - Newsletter EnginSoft Year 8 n°4
Sommario - Contents EVENTS
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EnginSoft CAE Conference 2011: 600 partecipanti all’annuale appuntamento EnginSoft CAE Conference 2011 welcomes an audience of 600 CAE users EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca
CASE STUDIES
12 15 18 19 20 23 26 29
Electromagnetic Issues for a IEEE 1902.1 “RuBee” Tag Dipped in a Fiber/Composite Laminate Structural Optimization of a Car-body High Speed Train - An Innovative Analysis and Design Methodology FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis Finalized to the Structural Verification of the FSO Mooring System FEM analysis in Oil&Gas Industry Numerical Analysis of a Micro Gas Turbine Combustor Fed by Liquid Fuel Reconsidering the Multiple Criteria Decision Making Problems of Construction Workers Using Grapheur Synergy between LS-DYNA and modeFRONTIER to Predict Low Velocity Impact Damage on Composite Plate Multi-objective Optimization with modeFRONTIER Applied to Systems Biology
TESTIMONIAL
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Eccellenza tecnologica e qualità: Almacis
SOFTWARE/HARDWARE NEWS
32 33 34 36 37
CAE Simulations and Innovations within the High Performance Computing HPC DIGIMAT per la modellazione avanzata dei materiali LIONsolver: Learning and Intelligent Optimization GPU Accelerated Engineering with ANSYS EnginSoft continua l’attività sui materiali compositi
EVENTS
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EnginSoft presenterà la release 5.2 di MAGMA a METEF 2012 La simulazione di processo nella progettazione di radiatori modeFRONTIER Users’ Meeting 2012 EnginSoft GmbH Silver Sponsor at the ANSYS Conference & 29th CADFEM Users’ Meeting 2011
The EnginSoft Newsletter editions contain references to the following products which are trademarks or registered trademarks of their respective owners: ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. [ICEM CFD is a trademark used by ANSYS, Inc. under license]. (www.ansys.com) modeFRONTIER is a trademark of ESTECO srl (www.esteco.com) Flowmaster is a registered trademark of The Flowmaster Group BV in the USA and Korea. (www.flowmaster.com) MAGMASOFT is a trademark of MAGMA GmbH. (www.magmasoft.de)
ESAComp is a trademark of Componeering Inc. (www.componeering.com) Forge and Coldform are trademarks of Transvalor S.A. (www.transvalor.com) AdvantEdge is a trademark of Third Wave Systems (www.thirdwavesys.com)
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LS-DYNA is a trademark of Livermore Software Technology Corporation. (www.lstc.com) SCULPTOR is a trademark of Optimal Solutions Software, LLC (www.optimalsolutions.us) Grapheur is a product of Reactive Search SrL, a partner of EnginSoft (www.grapheur.com) For more information, please contact the Editorial Team
Newsletter EnginSoft Year 8 n°4 -
RESEARCH AND TECHNOLOGY TRANSFER
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BENIMPACT Suite has landed in China
TRAINING
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Alta formazione: TCN punta ad una specializzazione sempre più avanzata
JAPAN CAE COLUMN
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CAE Seminars in Japan “CAE UNIVERSITY” NPO Activity for Implementation of Anisotropic Elasto-plastic Models into Commercial FEM Codes
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Newsletter EnginSoft Year 8 n°4 -Winter 2011 To receive a free copy of the next EnginSoft Newsletters, please contact our Marketing office at: [email protected] All pictures are protected by copyright. Any reproduction of these pictures in any media and by any means is forbidden unless written authorization by EnginSoft has been obtained beforehand. ©Copyright EnginSoft Newsletter.
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PAGE 8: ENGINSOFT CAE CONFERENCE 2011 WELCOMES AN AUDIENCE OF 600 CAE USERS
PAGE 12: ELECTROMAGNETIC ISSUES FOR A IEEE 1902.1 “RUBEE” TAG DIPPED IN A FIBER COMPOSITE LAMINATE
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ASSOCIATION INTERESTS
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NAFEMS International www.nafems.it www.nafems.org TechNet Alliance www.technet-alliance.com RESPONSIBLE DIRECTOR Stefano Odorizzi - [email protected] PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA
Autorizzazione del Tribunale di Trento n° 1353 RS di data 2/4/2008
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6 - Newsletter EnginSoft Year 8 n°4
EnginSoft CAE Conference 2011: 600 partecipanti all’annuale appuntamento La Fiera di Verona ha ospitato l’edizione 2011 del maggiore appuntamento in Italia dedicato al calcolo scientifico: l’EnginSoft International Conference, CAE Technologies for Industry e l’ANSYS Italian Conference. Oltre 600 i congressisti, esperti ed opinion leader in metodi e tecnologie CAE, che il 20 e 21 Ottobre scorso si sono incontrati, presso il Centro Conferenze del polo fieristico di Verona. Molte le aziende presenti, tra cui: Ansaldo, Piaggio, Magneti Marelli, Avio, Tetra Pak, Ferrari, Iveco, ENI, a dimostrazione dell’utilizzo crescente del CAE in ambito industriale. Tra gli obiettivi della Conference vi è stato quello di offrire ai partecipanti una visione d’insieme del comparto, attraverso il contributo di esponenti del mondo dell'industria, dell'università e della ricerca e dai numerosi sviluppatori di tecnologie intervenuti. “La Conference – ha spiegato Stefano Odorizzi, CEO di EnginSoft – è nata nel 1984 quando le tecnologie in fatto di sperimentazione virtuale erano solo oggetto di ricerca da parte delle università. Convinti che queste tecnologie avrebbero avuto un’evoluzione importante, abbiamo deciso di abbracciare la sfida e oggi continuiamo a perseguire l’obiettivo di trasferire agli operatori del settore le informazioni e le conoscenze relative a questi ambienti di simulazione e supporto alla progettazione”. Dopo la sessione plenaria di apertura che, oltre alla “Vision” da parte del Vice Presidente di ANSYS Inc., ha ospitato un mini simposio dedicato alla tematica del geo-modeling, l’evento è continuato su sessioni parallele, ognuna delle quali
Fig. 2 - Scorcio della sala conferenze di Verona nel corso di uno dei workshop.
Fig. 1 - Stefano Odorizzi - CEO di EnginSoft - in sessione plenaria.
focalizzata su una macroarea tecnologica o applicativa: meccanica, fluidodinamica, ottimizzazione, simulazione di processo, compositi, ecc. Di grande appeal sui partecipanti e di interesse perchè d’attualità, l’esperienza presentata da Ansaldo Energia di Genova in tema High Performance Computing. Stefano Santucci, IT manager di Ansaldo, ha illustrato le ragioni della migrazione da una struttura formata da sole workstation ad un cluster in cui l’hardware distribuito e HPC non solo convivono felicemente ma si integrano in un tuttuno estremamente efficiente sia in termini di performance di calcolo che di ritorno dell’investimento per tutta l’azienda.
Newsletter EnginSoft Year 8 n°4 -
Nel corso dei lavori relativi alla sessione sulla simulazione meccanica sono stati presentati alcuni importanti progetti tra i quali lo sviluppo di un’innovativo sistema di contenimeto di argon liquido, commissionato dal CERN di Ginevra, che consentirà di approfondire la ricerca scientifica sui neutrini. EnginSoft ha inoltre illustrato il progetto di un veicolo filoguidabile, realizzato in collaborazione con WASS, finalizzato all’esplorazione subacquea sino a quattromila metri di profondità. La sessione dedicata alla simulazione CFD (Computational Fluid Dynamics) ha, invece, reso evidente quello che è oggi, rispetto al passato, il ruolo centrale del progettista che, attraverso sofisticati strumenti di simulazione di cui può disporre, ha l’opportunità di focalizzarsi principalmente sull’aspetto ingegneristico del problema, delegando al software l’onere di governare gli aspetti matematici di base. Progettare in CFD oggi si traduce nella necessità di avere: efficienti funzionalità di dialogo con i sistemi CAD, procedure automatiche di meshing e parametrizzazione del modello. Tema centrale della sessione dedicata all’ottimizzazione è stata l’analisi dello stato dell’arte sulla simulazione multiobiettivo, tematica molto utilizzata in ambito automotive, dimostrato dalle testimonianze di Ferrari, Iveco e Continental. Novità e successo di pubblico anche per il workshop dal titolo “La progettazione delle strutture in materiale composito” coordinato da Marco Perillo e dal suo team di ingegneri. Scopo del seminario è stato quello di condividere lo stato dell’arte dei metodi di progettazione e degli strumenti di analisi strutturale sia sul piano teorico/concettuale, sia sul piano applicativo. A dimostrazione di molte tematiche verticali sostenute da EnginSoft, grazie anche all’esperienza nel progetto BENImpact, è stato inserito nel programma un workshop dedicato all’utilizzo del CAE in campo ECO-Building e progettazione sostenibile, il riscontro è stato notevolmente positivo e ha dimostrato l’ottima integrazione del CAE anche nelle tematiche “di frontiera”. L’attività congressuale, inoltre, è stata affiancata da un’area espositiva, in cui quasi 30 tra le più importanti software house CAE, sviluppatori hardware e di applicazioni
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complementari hanno condiviso con i partecipanti le novità relative ai loro prodotti. Particolarmente emozionante la Cena di Gala organizzata presso il vicino Museo dell’Auto e della Tecnica Nicolis. Qui i visitatori, prima delle portate, hanno potuto osservare automobili, motociclette e oggetti unici da collezione di epoche differenti. “Le tecnologie di simulazione rivoluzioneranno i processi progettuali attualmente adottati dalle aziende manifatturiere” ha concluso il CEO di EnginSoft. “Oggi si dice che queste tecnologie si integrano nel processo progettuale; in futuro oramai prossimo, queste tecnologie diventeranno il processo progettuale”. Con questo messaggio diamo ai lettori appuntamento all’edizione 2012 della CAE Conference EnginSoft, sperando di accrescere ulteriormente la community di analisti e imprenditori che credono nell’innovazione attraverso l’utilizzo delle tecnologie di sperimentazione virtuale. Per ulteriori informazioni: Luisa Cunico, EnginSoft [email protected] www.caeconference.com
ATTI DELLA CONFERENZA 2011 Sono disponibili in download gli atti della Conferenza EnginSoft 2011 all’indirizzo: www.enginsoft.com/proceedings2011
Fig. 3 - L’area espositiva in cui i congressisti hanno avuto l’opportunità di dialogare direttamente con i produttori di tecnologia presenti in sala.
8 - Newsletter EnginSoft Year 8 n°4
EnginSoft CAE Conference 2011 welcomes an audience of 600 CAE users The Exhibition Centre in Verona (Verona Fiere) hosted the 2011 edition of the major event in Italy on simulation based engineering and sciences, the EnginSoft International Conference, CAE Technologies for Industry, and the ANSYS Italian Conference. EnginSoft and ANSYS had the great pleasure of welcoming over 600 attendees, among them many CAE experts and opinion leaders, to the Congress Centre in Verona on 20th and 21st October. Representatives of large companies participated and contributed to the conference program as well: Ansaldo, Piaggio, Magneti Marelli, Avio, Tetra Pak, Ferrari, Iveco, and ENI, to name just a few. Their involvement underlined how CAE technologies are being used more and more in industry. One of the goals of the Conference was to offer the participants an overall view of such technologies with presentations from industry, universities, research organizations, and technology developers. “The Conference – explained Stefano Odorizzi, CEO of EnginSoft – was organized for the first time in 1984, when technologies in the field of virtual prototyping were just studied in universities. At the time, we saw great evolution, and this is what made us decide to invest in these technologies. Today, our goal is to transfer as much information and knowledge as possible about these simulation and design tools to the experts in this field”.
Fig. 2 - Welcome desk at EnginSoft area.
Fig. 1 - Swaminathan Subbiah - Vice President, Corporate Product and Market Strategy at ANSYS - during his speach talking about future developments.
The Plenary Session that opened the event, featured the “Vision” of the Assistant Director of ANSYS Inc. and a Mini-Symposium on geo-modeling. Later on in the afternoon, the program offered to the audience a number of parallel sessions focused on different technological fields: mechanics, fluid-dynamics, optimization, process simulation, composites, etc. One of the particularly captivating presentations on current topics was the contribution by Ansaldo Energia of
Newsletter EnginSoft Year 8 n°4 -
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Genova on High Performance Computing. Stefano Santucci, the IT manager of Ansaldo, explained the reasons why the company has left a structure with only workstations for a structure with a cluster, where the distributed hardware and the HPC were perfectly integrated thus generating an efficient computation performance and ROI for the company. In the session about mechanical simulation, some important projects were presented, such as the development of an innovative storage system for liquid argon - committed by CERN (European Organization for Fig. 3 - Some beauties inside of the Nicolis Museum - Verona. Nuclear Research) in Geneva – occasion, before the dinner started, our guests from that allows to perform in depth studies on neutrinos. On around the world enjoyed a guided tour of the large this occasion, EnginSoft explained the project of a wireexhibition rooms of the museum. guided vehicle, implemented with WASS, for underwater The CEO of EnginSoft closed the Conference saying that exploration activities of up to 4000 m under sea level. “Simulation technologies will radically change the design The CFD session stressed the central role of the designer processes currently used in manufacturing companies. nowadays, compared to the past. Today, we can focus on Now we are saying that such technologies are integrated the engineering side of the problem, thanks to in the design process; but in the next years they will be sophisticated simulation tools, by entrusting the the design process itself”. management of the basic mathematical processes to the With this message in mind, we ask our attendees and software. Designing in CFD means: effective connections readers to keep an eye out for the 2012 edition of the with CAD systems, automatic mesh procedures and model EnginSoft International CAE Conference parameterization. The session about optimization www.CAEconference.com hoping that the Virtual emphasized the state-of-the-art of multi-objective Prototyping Community will grow further and further until simulation, a topic commonly discussed in the automotive we meet again! field – as Ferrari, Iveco and Continental assured us. The workshop titled “The design of structures in composite materials”, managed by Marco Perillo and his For more information: team of engineers, also turned out to be a great success. Luisa Cunico, EnginSoft The workshop’s aim was to share the state-of-the-art of [email protected] the diverse design methods and the structural analysis www.caeconference.com tools, both from a theoretical/conceptual and applicative level. Another interesting workshop was connected to the CONFERENCE PROCEEDINGS 2011 BENImpact Project and the ECO-Building field. The results 2011 Conference Proceeding are now avaliable were incredibly positive and demonstrated how perfectly to download on: CAE is integrated in the “frontier” topics. www.enginsoft.com/proceedings2011 An important aspect of the annual event is the exhibition area. This year, nearly 30 of the most well-known CAE software houses showcased their hardware and software products. The conference attendees could hear about the latest developments and news in personal talks with some of the developers. Finally, another highlight was the Conference Gala Dinner, held at the Nicolis’ Museum of Cars, Technology and Mechanics, which houses a private collection of vintage cars and motorbikes of Mr. Luciano Nicolis. On this
10 - Newsletter EnginSoft Year 8 n°4
EnginSoft ha proposto una tavola rotonda sulla competitività d’impresa presso il nuovo centro di ricerca Il 24 Novembre scorso si è tenuta a Bergamo, in occasione dell’inaugurazione del nuovo Centro di Ricerca EnginSoft presso il Parco Scientifico Tecnologico “Kilometro Rosso”, una Tavola Rotonda dal titolo “Lean Design e Competitività d’Impresa - Innovazione e moderni strumenti per il management strategico”. All’evento, al quale hanno partecipato oltre 100 Top Manager delle più importanti imprese manifatturiere italiane mentre al tavolo dei relatori si sono seduti: Roberto Formigoni (Presidente Regione Lombardia), Alberto Bombassei (Vice Presidente Confindustria), Antonello Briosi (Vice Presidente Confindustria Trento), Mirano Sancin (Direttore Generale e Consigliere Delegato del Parco Scientifico Tecnologico Kilometro Rosso), Massimo Egidi (Presidente della Fondazione Bruno Kessler), Giancarlo Michellone (già Presidente di Area Science Park di Trieste e ora Presidente GMC Consulting), Marie Christine Oghly (Presidente MEDEF, Parigi), Sergio Savaresi (professore al Politecnico di Milano) e Stefano Odorizzi (CEO EnginSoft). Durante la tavola rotonda, condotta e moderata da Federico Pedrocchi - giornalista scientifico di ‘Radio 24-Il Sole 24 Ore’, gli opinion leader, provenienti dal mondo delle istituzioni, dell’impresa e della ricerca scientifica si sono confrontati sul tema dell’innovazione quale fattore chiave di successo e competitività d’impresa anche, ma soprattutto, in tempo di crisi di mercato. È Alberto Bombassei ad entrare in tema affermando che “… le strategie applicate dalla maggior parte delle aziende italiane - non solo PMI - fondate sull’innovazione incrementale e di processo, sostanzialmente finalizzate ad abbattere i costi di produzione e migliorare la qualità dei prodotti, non sono più sufficienti”. Aggiunge il presidente di Brembo Spa “in un mercato Globale, dove i paesi in via di sviluppo e con mano d’opera a basso costo la fanno da padrone, occorre sempre più innovare per essere competitivi e mantenere la leadership”. Gli fa eco Mirano Sancin, Direttore Generale di Kilometro Rosso, che aggiunge“… è l’innovazione radicale e di prodotto che contribuisce maggiormente a spostare le attività economiche, e produttive, da un’elevata concentrazione di manodopera (sempre più difficile da reperire) ad una elevata concentrazione di conoscenza (tipica dei sistemi più evoluti) e ad aumentare la competitività delle imprese a livello internazionale”. Anche le istituzioni collaborano, con l’imprenditoria e la ricerca strutturata, alla causa comune della competitività dell’impresa-Italia attraverso veri e propri strumenti finanziari costituiti dai Bandi. “Chi non ricerca non cresce” è
Fig. 1 - Alberto Bombassei, Vice Presidente di Confindustria, che commenta il contesto di mercato entro cui le aziende italiane devono operare
lo slogan citato da Roberto Formigoni e promosso da Regione Lombardia che nel biennio 2009-2010 ha stanziato fondi per oltre 80 milioni di Euro destinati alla ricerca e all’innovazione industriale. “Nonostante le difficoltà, le aziende virtuose continuano ad innovare, innovare e ad investire nella crescita – accenna il Governatore di Regione Lombardia - in un momento di difficoltà generalizzata, le aziende investono in ricerca per cercare nuovi margini di profitto e aprirsi a quel contesto di conoscenza distribuita che caratterizza la società moderna. È questo il dato positivo - conclude Formigoni - che emerge dai primi risultati del Bando Regionale”. “Le nuove tecnologie di simulazione e di analisi predittiva sono di fatto riconosciute da molte aziende un’effettiva rivoluzione dei processi progettuali” ha affermato Giancarlo Michellone. In questo contesto di ricerca applicata ed incubatore tecnologico si inserisce a pieno titolo anche EnginSoft che da tempo collabora con l’R&D di Brembo per la simulazione di sistemi frenanti e con l’Istituto Mario Negri per applicazioni farmacologiche: realtà entrambe insediate nel Parco Scientifico. Con oltre 30 ricercatori ed ingegneri impiegati
Newsletter EnginSoft Year 8 n°4 -
Fig. 2 - Overview della platea di Imprenditori e Top Manager che hanno partecipato alla tavola rotonda organizzata da EnginSoft a Bergamo
nella sede di Bergamo, l’azienda investe sul proprio futuro e rilancia la presenza in Italia trasferendo una delle sedi all’interno di un incubatore tecnologico d’eccellenza qual è il Kilometro Rosso. “È dal 2007 che collaboriamo con il Consorzio Intellimech e con altri laboratori di ricerca inseriti nel Parco Scientifico Tecnologico - afferma Stefano Odorizzi, Presidente di EnginSoft – in questi anni abbiamo toccato con mano l’importanza di far parte di questa struttura che condivide la nostra stessa mission: sviluppo di tecnologia e innovazione”. L’evento di oggi promosso da EnginSoft, in uno dei rari casi in cui istituzioni, ricerca universitaria e impresa si riuniscono a confronto su temi strategici e di vitale importanza per il sistema-Italia, è la riprova del consenso e dell’autorevolezza che l’azienda, negli anni, ha riscosso sul mercato. Per ulteriori informazioni: Mosè Necchio - EnginSoft [email protected]
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La gestione progetto in ottica Lean Design Sviluppare processi di progettazione e sviluppo-prodotto sempre più rapidi ed affidabili è oramai riconosciuta quale una necessità strategica imprescindibile. È quanto è emerso, in estrema sintesi, dal simposio di Bergamo. Per esplorare diverse alternative di soluzioni è necessario essere rapidi e tempestivi nell’apprendere i limiti e le potenzialità di ciò che stiamo ideando e progettando. La velocità e l’efficacia nell’esplorazione delle alternative, quindi, sono profondamente legate alla capacità di sperimentazione attraverso un numero significativo di prototipi ognuno funzionale alla verifica delle intenzioni di progetto e la loro corrispondenza alle necessità del cliente. Questo approccio, mediante l’impiego di prototipi fisici, potrebbe richiedere tempo e risorse in numero incompatibile con il budget disponibile. Anche nei processi di innovazione-prodotto esistono forme di “spreco” definibile in: qualsiasi attività che non crea Valore per il cliente. Il tema su cui riflettere è che tali sprechi non sono immediatamente visibili e non sono, quindi, facilmente aggredibili se non attraverso le giuste metodologie per individuarli. La riprogettazione dei processi di innovazione-prodotto, in chiave sperimentazione virtuale, può liberare enormi energie creative e di conoscenza che frequentemente sono già presenti negli uffici tecnici e di calcolo. EnginSoft, su questo tema, sta elaborando e sviluppando iniziative ad hoc finalizzate a diffondere le metodologie di Lean Design con la relativa valutazione del ROI soprattutto attraverso l’impiego della Simulazione e della Sperimentazione Virtuale.
12 - Newsletter EnginSoft Year 8 n°4
Electromagnetic Issues for a IEEE 1902.1 “RuBee” Tag Dipped in a Fiber/Composite Laminate The IEEE 1902.1 “RuBee” communication standard defines the air interface for radiating transceiver radio tags using long wavelength signals (up to 450 kHz). Conforming devices can have very low power consumption (a few microwatts on average), while operating over medium ranges (0.5 to 30 meters) and at low data transfer speeds (300-9600 bps). In this article, the approach to model a loop tag operating at 131.072 kHz through ANSYS Maxwell v.14 is described when the sensor is dipped in a multilayer fiber/composite laminate. Some preliminary results are shown in terms of input inductance and magnetic fields. Free standing antenna modeling Fig. 1 shows the prototype and the numerical ANSYS Maxwell model of a magnetic loop antenna for the short range “RuBee” protocol. The antenna (Fig.1a) is a 42mm radius multi-turn coil made of 33 loops of a copper wire with a section radius equal to 0.25mm. The numerical model is made of a solid single wire with a circular section
Fig. 2 (a) - Prototype of the multi-turn microstrip coil and (b) Maxwell 3D model. The PCB connector is visible in the bottom of Fig. 1a. The two side copper plates are helpful to tune the antenna input impedance.
CPW fed antenna is made of 16 properly distanced 0.6mm wide microstrip copper line turns. The background scenario was modeled by imposing radiation boundaries to the problem region in order to simulate free emission into space. In the operational environment, the latter could be a lossy and/or conductive media like sea water and oil (see Table I for more details) and it should be consequently modeled with the correspondent electric characteristics.
Table I - Dielectric characteristics of some media compared with free space
Fig. 3 shows a sample of the electric current density along the loop and on the solid wire section. The imposed
Fig. 1 (a) - Prototype of the 33-turn copper wire coil and (b) geometrical details of the Maxwell 3D model. In the top of Fig. 1a the microstrip feeding line and the PCB connector are visible.
radius rls equal to 0,143cm. As indicated in the bottom of Fig. 1b, this value corresponds to the radius of a circumference with a surface equal to the sum of the 33 wire sections. The second element is a multi-turn printed loop on a 0.8mm thick FR4 laminate and it is shown in Fig. 2. The
Fig. 3 - Sample of the current density distribution along the loop
Newsletter EnginSoft Year 8 n°4 -
stranded current, constant on the wire section, is visible in the bottom left detail and, as expected, the current is constant along the loop. Fig. 4 shows a sample of the magnetic induction distribution in a plane containing the loop axis. This B field distribution is a well-known result, according to basic electromagnetic theory. Indeed, the loop length is much smaller than the free space wavelength at 131 kHz (around 2.3km), so resulting in an elementary loop design. For such elements the near field is mainly magnetic and completely decoupled by the electric field.
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some other aspects could make the printed square loop preferable, like its mechanical stability and the more accurate repeatability of the prototyping. Table II shows the simulated and measured values of the input inductance for the two configurations. For the solid loop case, the calculated value is obtained from a correspondent analytical
Fig. 6 - H field distribution along the loop axis for the wire solid ring and the printed microstrip square loop.
Table II Input inductance for the two antenna configurations Fig. 4 - Sample of the magnetic induction in a plane orthogonal to the sweep.
Even if the device is an antenna, this consideration justifies the use of ANSYS Maxwell 3D rather than ANSYS HFSS because the magnetic near field characterization provided by Maxwell 3D fully satisfies the design requirements.
model and this is in good agreement with the simulated one. The measured inductance is around 10% less than the previous cases. This disagreement results from the mismatch between the transverse section areas of the solid loop of the simulated and calculated cases and the 33-turn one of the prototype (see the bottom detail of Fig.1b). A 0.9 fill factor (Fig.1a) corresponding to the missing lighter areas of the prototype with respect to the numerical models should be considered to compensate it. An excellent agreement between simulations and measurements is apparent for the printed element. Electromagnetic modeling and analysis of the composite laminate The two prototypes would be dipped in a composite material as shown in the sample of Fig. 7. A composite laminate can be schematized as a stack-up of several plies, each of them made of a sheet of fibers filled
Fig. 5 - Details of the mesh characteristics for the microstrip printed loop
Fig. 5 shows a sample of the mesh for the microstrip printed square loop. Around 161000 tetrahedra were used for the computational domain and around 24000 for the loop. For the solid wire loop 61000 tetrahedra were necessary for the computational domain and 14000 were used for the loop. Fig. 6 shows the H field distribution along the loop axis, for both configurations. The H field is higher for the wire loop, suggesting the use of this antenna type. However,
Fig. 7 - Sample of rectangular loop dipped in a fiberglass composite laminate.
14 - Newsletter EnginSoft Year 8 n°4 isotropic, in the sense that only their intrinsic dielectric characteristics are known. On the other hand, the structures in Fig. 8b and c are generally anisotropic, as a result of the applied methodology. The permeability and permittivity tensors need to be calculated according to the material properties and to the problem geometry, as:
Fig. 8 - Single composite ply: (a) schematic model, (b) equivalent model for the intermediate fiber/resin layer, (c) equivalent model for each single ply
where:
and g is a function of the ratio between the fiber and the resin volume in the intermediate layer of Fig. 8a. Fig. 9 shows the Maxwell 3D model with 4 plies above and 4 plies below the wire antenna. Fig. 9 - Example of a composite laminate made of 8 plies: 4 above and 4 below the wire loop antenna
with some dielectric resin, as shown in Fig. 8a. An df thick intermediate layer made of some fibers and resin lies between two dr thick single layers of resin. This structure could generally be dissipative, conductive and anisotropic, the latter depending on the characteristics and the distribution of the fibers.
Each ply has been modeled in Maxwell 3D, including all the material anisotropies and dielectric properties. The work on the analysis of the effect of a number of plies up to 64 is in progress. They have been fully parameterized in order to take into account a number of possible ply configurations and materials.
An effective approach to model this structure is to define an equivalent layer for each ply. Many models have been recently presented, resorting to different approaches but all of them afford a specific problem without deeply challenging a general approach. In the framework, the approach to model an equivalent layer for each ply is to apply the method described in for the intermediate layer of Fig. 8a, in order to get an equivalent anisotropic intermediate one, shown in Fig.8b.
Conclusions In this work, the approach to analyze the electromagnetic performance of a tag antenna for the IEEE 1902.1 “Rubee” protocol has been described through the use of ANSYS Maxwell. Preliminary results have been shown in terms of radiated magnetic field and input inductance for both numerical models and prototypes. Simulated and measured results are in excellent agreement, proving the tool reliability. The methodology to model a multi-ply composite fiber material has been defined and numerical analyses on the antennas’ performance in its presence will be the main topic of some future investigations.
Then, a circuital approach can be applied to the multilayer structure shown in Fig. 8b to result in a single layer equivalent anisotropic model. It is worth noticing that all the constitutive materials (fibers and resin) in Fig. 8a are
Per ulteriori informazioni: Andrea Serra, EnginSoft [email protected] Thanks to Federica Bolognesi, IDNOVA
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Structural Optimization of a Car-body High Speed Train - An Innovative Analysis and Design Methodology In the past, the main challenge was to achieve a very high speed, but today the criteria such as energy efficiency, high transport capacity, comfort and low environmental impact are becoming more and more important. For this reason the philosophy of AnsaldoBreda is to combine a settled design process with innovative approaches to optimize the reliability, safety, low power consumption and an easy maintenance. In order to be competitive in the market, especially in this economically challenging period, it is necessary to push the envelope of the available technologies to ensure compliance with top level quality standards. A new methodology approach has been developed by exploiting the new capabilities of the multi-objective design environment modeFRONTIER and it has been applied to the design of the carbody structure of a new generation of High Speed trains. In this context, the aim of the activity was the design optimization of the aluminum carbody structure in terms of weight and dynamic behavior, respecting all project constraints according to the high standard structural and crash requirements of European EN 12663 - Category P-ll (Fixed units) and TSI Rolling Stock. Starting from the CAD model of the original configuration, the FE comprehensive parametric model has been developed by ANSYS APDL procedure and integrated into the
modeFRONTIER optimization platform to achieve the requested goals. The FE parametric model has been divided into two different main parts: 1. The central parts of the carbody (named “fuselage”) – as shown in fig.1a; 2. The terminal tapered parts of the carbody – as shown in fig.1b. The fuselage geometry (fig.2) is completely parametric in terms of:
Fig.2 - Section profile of carbody
a) number of the profile reinforcements; b) angle, position of reinforcements; c) thickness of reinforcements; d) thickness of external and internal skin of profiles. The aims of the optimization process of a carbody in modeFRONTIER are: a. Minimizing weight b. Maximizing two first own frequencies Fig. 1a - Fuselage Parametric part of high speed train: it has been completely development in ANSYS APDL. Fig. 1b: No -parametric part of high speed train: terminal tapered parts are fixed geometry
with the following constraints: a. Max Von-Mises stress for static analysis
16 - Newsletter EnginSoft Year 8 n°4 b. Max Von-Mises stress for equivalent crash analysis c. Max Von-Mises stress for fatigue analysis d. Min buckling factor for linear instability analysis The original configuration, only referred to the parametric part of the carbody, weighs 5.927 Tons. The main goal is the weight reduction by min. 500 Kg, maintaining the first bending frequency of 11 Hz. The static structural analysis and fatigue analysis have been performed for both welded and unwelded region (fig.3), which have different material features:
Only the modal analysis has been performed to find out the best region for weight and frequency with no timeconsuming run (less than 1 hour on the cluster machine). The results of this first optimization loop has been used as a starting DOE (Design of Experiment) for the second one, where objectives/constraints related to displacement under pressure loads and to the 5-6 strongest load cases (fig. 4) have been introduced. This step is more time-consuming than the first one (5 hours on the cluster machine). After these optimization loops, some variables have been changed in agreement with AnsaldoBreda, and the final
Fig.3 - Section of a carbody structure
Due to the high number of time-consuming simulation and the high number of input variables, a progressive approach has been studied for the optimization analysis. Therefore, the optimization analysis has been carried out in three steps: • Step1: Screening, driving towards the best designs region; • Step2: Rough refinement, including the most important constraint conditions; • Step3: Final refinement, achieving the optimal solutions.
optimization run has been done to achieve the best solutions. Since this step was really time-consuming (15 hours on the cluster), the problem has become to monoobjective: only the weight has been considered, while the other objective has become constraints (fig. 5). The set of best designs belonging to the new Pareto frontier has been verified for each operative load condition and the best designs have been chosen using decision making tools. The optimal designs selected on the basis of stress and weight values have a considerable variation of both external and internal skin thickness, which can cause manufacturing problems. In order to avoid such problems, another post processing analysis has been done to find out Pareto solutions with a homogeneous distribution of thickness
A total of 23 different working -load cases have been considered, with an additional specific comfort requirement about Static Pressure load (-8 KPa inside Tunnel) which constrained the side walls displacements (Uy < 3mm and Uz < 4.5 mm) The whole simulation took 3 weeks on cluster machine with 8 parallel simulation (32 core). The first optimization step has been carried out taking into account the two most important objectives of the problem (increase of frequency and weight reduction) which lead the designs to the best region Fig.4a - History of weight convergence and allows to reduce the design (green points: 1st optimization loop; blue points: space of the input variables. 2nd optimization loop).
Fig.4b - displacements in y direction (mm)
Newsletter EnginSoft Year 8 n°4 -
along external and internal skin. New post processing using “parallel chart” applied on best design has been carried out in order to find a suitable solution matching the new requirements introduced a-posteriori (fig. 6). Table II shows the comparison between the best design selected at the end of the optimization analysis (Design ID 378) and the best design after the last post processing considering a thickness uniformity (Design ID 339). Thanks to the implemented methodology and the optimization routine, a considerable weight reduction has been reached. The chosen solution, Design ID 339, has a weight reduction of 546 Kg (- 9.2%) and it has a more uniform thickness variation which simplifies the carbody manufacturing. This work aims to shows how to exploit new design methodologies and new technologies in order to manage industrial design processes that involve a large number of variables (more than 50), several constraints and objectives, finding the best solution according to industrial timing. It is possible to summarize the most important steps of this activity, as follows: • The design optimization procedure developed has been completely automated: this allowed to make the most of all available hardware and software resources, completely exploiting the downtime (nights and holidays). • The requested weight reduction has been achieved respecting every structural and comfort requirements: this has totally fullfilled the expectations of the modeFRONTIER industrial users. • The additional requirement about manufacturing has been fulfilled without rerun any analysis thanks to the new methodology approach: this has been possible thanks to the really powerful capabilities of the post-processing tools of modeFRONTIER. • The optimization methodology can be completely re-used for other design processes: this activity was dedicated to a specific carbody but this approach can be easily adapted also to other railway vehicles. For more information: Francesco Franchini, Enginsoft [email protected]
Fig.5 - The workflow of modeFRONTIER with all input and output variables, the final objective and constraints
Table I - The table above summarize the optimization strategy adopted. The total number of design has been run in 20 days
Fig.6a - Parallel chart of the best designs
Fig.6b - The selected design (Design ID 339) with homogeneous thicknesses
Table II - comparison between the original solutions and the optimized solutions
Table III - Thickness comparison of the side walls of fuselage (profile ref. 5-6-7-8)
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FSO and Shuttle Tanker in Tandem Configuration Hydrodynamic Analysis Finalized to the Structural Verification of the FSO Mooring System Strength and Fatigue Verifications of an FSO mooring system have been performed basing the results on proper hydrodynamic analysis (developed inside ANSYS-AQWA) and structural analyses (developed inside ANSYS-Workbench) of the system and relevant components. Hydrodynamic Analysis The FSO (109.000 DWT), operated by Edison, is moored on the Rospo Mare Offshore Oil Field. The FSO mooring is guarantees via 6 chains connected to a rotating turret, installed at the FSO bow. During the oil offloading operation, the Shuttle Tanker (45.000 DWT) is moored, via an hawser, at the FSO aft end. The offloading operation takes place under proper sea conditions, with waves characterized by significant height (Hs) ad zero up-crossing period (Tz). To each sea state, consistent current and wind have been accounted for. The hydrodynamic model (performed inside Ansys-AQWA suite), simulating the FSO and the Shuttle Tanker (this one moored, at its stern, to a Tug via a mooring cable), refers both to aligned and misaligned meteo conditions (current incoming at 50 degrees with respect to wave direction, wind incoming at 25 degrees with respect to wave direction). On the model (FSO + Shuttle Tanker + mooring lines), time domain hydrodynamic analysis has been performed for each defined sea-state, obtaining, for each mooring chain and for the hawser connecting FSO and Shuttle Tanker, the axial tension as function of time. In order to check the strength resistance of mooring components (such as Chain Stoppers and 'Ecubier') installed at the rotating turret, besides hydrodynamic analyses under offloading conditions, also hydrodynamic analyses of FSO in moored condition, for extreme storm case (100 years return period), have been performed. Strength and Fatigue Verification of Chain-Stopper and “Ecubier” Based on results of hydrodynamic analysis performed for both extreme and offloading conditions, strength and fatigue verifications of Chain Stopper and ‘Ecubier’ have been performed. Strength checks have been based on results obtained from contact non-linear analysis performed of Finite Element
Model of Ecubier + Chain Stopper under extreme load case (practically the chain minimum breaking load). Fatigue checks have been developed according to spectral approach as required by DNV OS-E301 (Position Mooring), assuming proper S/N curve data as reported in DNV RP-C203 (Fatigue Design of Offshore Steel Structures). The assumed hypothesis at the base of fatigue spectral approach is that the stress range, S, is a random variable characterized by a probability density equal to p(S) and that, for each sea-state, the number of cycles having stress variation in the range of S and S+dS is directly related to ni p(S), where ni is the total number of cycles of that sea-state. Based on this and on the fact that, for offshore structures, the probability density of stress ranges, p(S), can adequately be represented by a Rayleigh distribution, the
Fig. 1 - Hydrodinamic Model of FSO, Mooring Lines, Shutter Tanker
Fig. 2 - Von Mises Stress distribution on Ecubier and Chain Stopper
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damage, Di, for the i sea-state, is given by the following relation:
Fig. 3 - Finite Element Model of Ecubier and Chain Stopper
where a and m are factors of S/N curve (C curve has been considered for fatigue verification of Ecubier and Chain Stopper), while σs is the standard deviation of S distribution. Finally, based on Miner-Palmgreen relation, the total damage, D, due to the summation of damages of each seastate, Di, is:
Enrico Miorin, Fabiano Maggio, Livio Furlan EnginSoft
Fig. 4 - S/N Curves in sea-water with cathodic protection
For more information: Livio Furlan, EnginSoft [email protected]
Design and FEM Analyses in Offshore and Oil&Gas Industry Besides competencies in Automotive, Aerospace and Industrial Engineering Simulations, EnginSoft has knowledge also in the Design and Analyses voted to the Oil&Gas and Offshore Industry. Many consultancy activities have been performed via collaborations with the most important Italian players in this sector: ENI, Saipem, Tecnomare, MIB Italiana, Petrolvaves, Cameron, FBM, Officine Resta, Nuovo Pignone, ATB, Foster Wheeler. EnginSoft can supply a full range of services covering projects entire design route, from the earliest conceptual studies passing through FEED and basic design up to detailed design and installation engineering. The following list reports some of the Oil&Gas Business Unit competences: • Conceptual and detailed design and structural analysis of fixed offshore platforms (jacket, top-sides, buoyancy tanks, stiffened structures) • Design and analysis of subsea foundation templates • Design and analysis of pressure vessels, valves, piping, rack, etc. • Design and analysis of subsea manifold (even for installation, repairing and retrieval operations) • Detailed structural analysis of structural parts (Hulls, Deck, etc.) of Semi-Submersible Vessels • Detailed structural assessment of steel Gravity Based Structures (GBS) including stiffened plate code checks • Detailed design and structural analysis of risers and FPSO's mooring connectors • Revamping of fixed offshore platforms (assessment of structural reliability- re-certification and life extension), fracture and fatigue assessment of installed jacket structures (risk analysis) • Motion Analysis of Floating Vessels (even for Marine Pipeline Installations) The BU, which is located in EnginSoft Padova Office and is coordinated by Livio Furlan, has high skills also in the field of structural and mechanical applications in general (as an example the design and analysis of Roller Coaster structures and cars or the design of large valves for hydroelectric power plants). For more information: Livio Furlan, EnginSoft - [email protected]
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Numerical Analysis of a Micro Gas Turbine Combustor Fed by Liquid Fuel This work presents a CFD analysis of the combustion chamber of a 50 kWel nominal power micro gas turbine. The purpose of the analysis is to investigate the combustion process and performance of the combustion chamber fed by liquid fuels, through 3D numerical simulations performed with ANSYS CFX 13.0. Firstly, a sensitivity analysis was carried out in order to determine the parameters for the correct modeling of the liquid injection. Then, a simulation campaign was conducted to investigate the case of Jet A feeding and the supply with different liquid fuels deriving from biomass. Introduction Nowadays micro gas turbine (MGT) are one of the more flexible and effective system for the distributed and residential micro cogeneration, due to their compact size, the low operating and maintenance costs, their greater overall conversion efficiency and reduced environmental impact. The continuous flow operation of this system offers a greater flexibility with respect to the unsteady process of internal combustion engines that imposes constraints on fuel characteristics. In particular, MGTs can be supplied with fuel (both gaseous and liquid), characterized by a higher level of contamination thanks to their greater adaptability to different fuel supply. Among the renewable sources, an increasing interest has been shown in fuels derived from biomass since they are a predictable source, allowing the distributed grid-connected generation without causing discontinuities in the electric grid and frequency instabilities. At the same time, vegetable oils have gained attention since they can be low-cost fuels and allow to implement
systems for the distributed energy production. MGTs are not well-established systems for straight vegetable oil feeding, yet, because the combustion of these oils had to be investigated due to the opposite physical and chemical characteristics, such as the chemical composition, the lower heating value (LHV), the molecular mass, the density and the viscosity, compared to diesel, biodiesel, dieselvegetable oils and their mixtures. In fact, the combustion performance depends on the atomization process and spray characteristics, which are directly related to the fuel composition and its physical properties, in particular the high viscosity of vegetable oils. The study presented below regards the preliminary analyses performed on a MGT combustion chamber fed by conventional fuel (Jet A), in order to find the correct settings for the simulation of biofuel feeding. Computational domain and numerical models Geometry. The numerical analysis have been conducted on the combustion chamber of Solar T62-T32, a micro gas turbine of 50 kWel nominal power, fed by diesel fuel. The combustion chamber (Figure 1a) is a reverse-flow annular type combustor, with six fuel injectors, 24 dilution holes and a series of holes for the cooling of the liner wall. The air from the compressor enters the combustion chamber in counter-current with respect to the combustion gases, passing through the space between the external wall and the liner’s wall. The solid domain of the combustion chamber (Figure 1b) was obtained from the direct measurement of the real geometry (Fig. 1a). Thanks to the periodicity of the number of fuel nozzles, dilution holes and wall cooling holes, the fluid domain was reduced to a 60° annular sector of the combustor (Figure 1c).
Figure 1 - (a) real combustor geometry, (b) solid domain, (c) grid of the fluid domain.
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parameters that better predict the behavior of this type of combustor, sensitivity analyses on the boundary conditions have been carried out. Boundary conditions influence One of the ways to reduce the particle spray diameter and, therefore, to obtain a finer spray, is to increase the atomizing air mass flow, which also applies to high viscous fuels. A larger flow of atomizing air can be obtained by modifying the bypass Figure 2 - Comparison of the results of the air/fuel ratio variation: temperature distributions. from the main machine compressor or by adding external air from an auxiliary compressor. So the influence of the air mass flow coming from the compressor has been evaluated. The air mass flow to fuel mass flow ratio, AFR, was varied from the standard value of 70 to 50 (rich combustion) and 100 (lean combustion). Figure 2 shows the comparison of the temperature contour plots in the nozzle mid plane: the flame increases in terms of extension and intensity as α increases, as Figure 3 - Comparison of the results of the particles’ diameter variation. expected. The quantitative results showed that the values of the turbine inlet Grid. Two unstructured tetrahedral grids with an overall temperature (TIT) and pollutant emissions, such as NOx and number of elements approximately equal to 1.5 and 2.5 CO, of the case of standard air/fuel ratio (ARF = 70) are in million respectively were generated using ANSYS ICEM CFD. good accordance with the measured pollutant Both grids are characterized by a uniform distribution of the concentrations and the calculation of the TIT by means of a elements inside the domain, with a more refined mesh gas turbine Cycle Deck. For these reasons, an air/fuel ratio inside the nozzle and combustion zone. of 70 was chosen for the subsequent simulations. The sensitivity analysis of the grid showed that both grids achieved the numerical convergence and were robust with Spray parameters influence compared to the overall performances of the combustor. For The simulation of liquid fuel combustion has been carried these reasons the 1.5 million elements grid (Fig. 1c) was out defining a particle injection region placed nearby the used in the numerical analyses presented below. fuel inlet surface, which is closed to the exit of the fuel injection duct. Sensitivity analyses concerning the diameter Numerical models and boundary conditions. The numerical of the particles injected into the combustor and the angle models adopted are: the k-ε for turbulence, the Eddy of the injection cone have been performed: in particular, Dissipation (EDM) for combustion with a 2-steps reaction three diameter sizes (1, 10, 20 µm) and three injection scheme and a PDF model as the NOx formation method. A cone angles (10°, 20°, 30°) were investigated. particle injection region and the TAB (Taylor Analogy Breakup), as secondary breakup model, were set at the fuel In the case of variation of the particle diameter, the flow inlet surface in order to model the fuel spray, while the field and the temperature distributions in the nozzle mid primary breakup was not activated. An adiabatic boundary plane have not presented significant modifications. The condition was set for all the combustor walls. Fuel inlet values of TIT and pollutant emissions (NOx and CO) boundary condition was set according to the data provided calculated at the outlet surface of the combustor has by the manufacturer, while the air mass flow value was decreased as the particle diameter has increased, according obtained from literature. All the numerical simulations were to the liquid fuel combustion phenomena. The evaporation performed with ANSYS CFX 13.0. time of the particles has increased as they have increased in size, while the particle traveling distance has increased CFD Analysis of the combustion chamber in an irregular way, as shown in Figure 4. A great increase Case of conventional fuel feeding has occurred passing with diameter between 10 and 20 µm In these cases the simulation regards the supply with and a decrease has occurred with a diameter between 1 and conventional fuel, so the Jet A fuel of the CFX material 10 µm. This was probably due to the size of the grid library has been used. In order to determine the simulation elements. Nevertheless, numerical values were in
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Figure 4 - Comparison of the results between Jet A and mock biofuels: particle traveling distance and temperature distribution.
accordance with it. When the spray cone angle has varied, the vaporization time and the traveling distance of the particles increased as the cone angle has increased. Temperature values into the primary combustion zone are lower in the case of a cone angle of 30°; the TIT value decrease accordingly. An anomalous behavior occurred when cone angle of 20°: there is a reduction of the particle traveling distance and the evaporation time; the TIT value is in accordance with the other simulated cases. According to the results of the sensitivity analyses already performed, an air/fuel ratio of 70, a diameter of 10 µm for the particle injection and a spray cone angle of 30° have been chosen for all the simulation presented below. Case of vegetable oil fuel feeding Subsequently, some simulations have been performed in order to investigate the behavior of the combustor in case of feeding with liquid fuel derived from biomass. As first attempt, two mock biofuel have been created starting from the Jet A characteristics and modifying only some of the parameters (density and viscosity values), in order to determine the influence of a single parameter each time. The density value, equal to 914 kg/m3 at 20 °C and the dynamic viscosity value, equal to 40 cP at 20 °C, comes from a direct measurement of a sample of rapeseed oil derived from dedicated crops (experimental crops realized within a research project on short energy chain). As a reference, default Jet A density and viscosity values at 20 °C are 780 kg/m3 and 1.5 cP, respectively. Figure 4 shows that the temperature distributions of the mock biofuels differ from the Jet A feeding in terms of intensity and flame morphology. The maximum temperature values in the mock biofuel cases are higher than the ones in Jet A case within the primary combustion zone, and the flame of Jet A case is more stable and there is less variation in temperature values. In terms of flame morphology, the base of the flame starts at the nozzle exit in Jet A case, while in mock biofuel cases it seems to even start inside the
nozzle. The highest values in the primary combustion zone are probably due to the lower flow velocity that produces an increase in the residence time, which come out from the analysis of the velocity field and the particle traveling distance pattern. The average values of TIT, NOx and CO calculated at the outlet surface of the combustor are not influenced by the density and viscosity variation.
Conclusions The aim of this work is to study the combustion phenomena related to the liquid fuel feeding of the annular combustion chamber of a micro gas turbine with an electric power of 50 kW. The main parameters of the fuel spray were investigated in the case of conventional fuel supply (Jet A) setting different values of particle diameter and cone injection angle. No significant modifications in terms of flow field and temperature distributions were noticed from the sensitivity analyses on spray parameters. The values of TIT and pollutant emissions (NOx and CO), calculated at the outlet surface of the combustor, decrease as the particle diameter increases, according to liquid fuel combustion phenomena. The evaporation time of particle and the particle traveling distance increase as dimension and cone angle increase, leading to slower combustion and, at the same time, a longer flame in the combustor. Particles with a diameter of 1 µm present an anomalous behavior in terms of the particle traveling distance and mean particle diameter, which is probably due to the size of the grid elements. Subsequently, a numerical analysis was performed in case of biofuel supplying. A mock biofuel was used by setting the values of density and viscosity of a rapeseed vegetable oil obtain from mechanic extraction of dedicated crops. The setup of the model parameters was performed by starting from the sensitivity analyses carried out in case of Jet A feeding. The analysis of the particle track shows that there is an increase in the particle traveling distance and the particle time as the fuel viscosity increases and the consequent increase of the residence time. This leads to higher temperature values inside the primary combustion zone. The global performance of the combustor (TIT and pollutant emissions) are not influenced by changes in density and viscosity.
Michele Pinelli, Anna Vaccari Università degli Studi di Ferrara
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Reconsidering the Multiple Criteria Decision Making Problems of Construction Workers Using Grapheur We are dealing with a series of multiple criteria decision making problems and analysis related to Canadian construction projects including waste management, productivity improvement, human and IT factors, emergy based lifecycle, and process optimization. The urgent increase of using IT in construction projects has been considered as one way to improve the process of solving our problems. Construction project managers have to make tough decisions. They have been considering different IT tools and would like to invest on getting better data analysis tools for enhancing their decisions. However, making critical decisions for complicated and multiple criteria construction projects problems in which huge amount of data are involved is not a simple task to do. As the della Ford allo 'iPod' di Apple, essi hanno identificato i principi e gli strumenti per neutralizzare la concorrenza e creare uno spazio di mercato incontestato, dalle possibilità illimitate come quelle di un oceano blu. Strategia Oceano Blu porta un messaggio carico di ispirazione: il successo non dipende dalla concorrenza spietata né da costosi budget di marketing e R&S, ma da mosse strategiche brillanti, adatte a un uso sistematico da parte di tutte le imprese.
Dettagli del libro Titolo: Strategia oceano blu. Vincere senza competere Autori: W. Chan Kim, Renée Mauborgne Editore: Etas Collana: Management Data di Pubblicazione: 2005 ISBN: 8845308480 ISBN-13: 9788845308482 Pagine: 288
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GPU ACCELERATED ENGINEERING with ANSYS also required for going parallel for greater than 2 CPU cores. For academic license users, the GPU capability is included with the base ANSYS Academic license that provides access to ANSYS Mechanical. How much more could you accomplish if simulation times could be reduced from one day to just a few hours? As an engineer, you depend on ANSYS Mechanical to design high quality products efficiently. To get the most out of ANSYS Mechanical 13.0, simply upgrade your NVIDIA Quadro GPU or add a NVIDIA Tesla GPU to your workstation, or configure a server with NVIDIA Tesla GPUs, and instantly unlock the highest levels of ANSYS simulation performance.
Here is an example of the speed-up you can reach within ANSYS13.
With the upcoming ANSYS Mechanical 14.0 engineers will even more benefit from NVIDIA GPUs.
With ANSYS® Mechanical™ 13.0 and NVIDIA® Professional GPUs, you can improve your product quality with 2x more design simulations or you can develop high fidelity models with practical solution times. This accelerates your timeto-market by reducing engineering cycles. The amount of acceleration achievable when using the GPU will vary greatly depending mostly on the model of the simulation, but also on the hardware configuration being used. To get the best speed-up the simulation should spend most of its time in the matrix solver operations rather than other tasks, such as matrix assembly. Also the problem size should be between 500K to 8,000K DOFs for the sparse direct solver and 500K to 5,000K DOFs for PCG/JCG iterative solvers. To unlock the GPU feature in ANSYS Mechanical 13.0, you must have an ANSYS HPC Pack license, the same scheme
NVIDIA and ANSYS have collaborated to bring you the power of GPU computing for ANSYS. With the latest release of ANSYS R13, NVIDIA GPU acceleration enables faster results for more efficient computation and job turnaround times, delivering more license utilization for the same investment. This will continue with even more features and optimizations in the upcoming release of ANSYS.
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EnginSoft continua l’attività sui materiali compositi La progettazione di un componente in materiale composito rappresenta una sfida complessa ad elevato contenuto tecnologico che coinvolge attualmente settori industriali profondamente diversi, dall’aerospace alla nautica, sino all’automotive ed applicazioni sportive più spinte. Il CAE svolge un ruolo sempre più importante in questo senso, rappresentando lo strumento in grado di riprodurre in maniera fedele ed accurata un prototipo virtuale dei componenti realizzati in materiale composito. ESAComp ed ANSYS Composite Prep/Post rappresentano ad oggi lo stato dell’arte dei software per la simulazione dei compositi; il loro avvento, sin dalle prime release, ha permesso di superare definitivamente i limiti intrinseci del classico approccio seguito per la progettazione delle strutture in composito, consentendo una caratterizzazione dettagliata dei materiali di base (fibre, matrici, core in schiuma o honeycomb, ecc.), una accurata gestione della laminazione attraverso la simulazione delle fasi tecnologiche di stesura dei tessuti (Draping & Flat Wrap) e una dettagliata verifica degli stati tensionali avvalendosi di Failure Criteria polinomiali (Tsai-Hill, TsaiWu, ecc.) e basati sulla natura fisica dei compositi (Hashin 2D/3D, Puck 2D/3D, ecc.). EnginSoft, attraverso l’organizzazione di seminari a tema dal taglio fortemente tecnico, è costantemente impegnata in attività di formazione avanzata; l’obiettivo principale è quello di sensibilizzare le società leader nel settore ed i principali istituti di ricerca nella valutazione dell’efficienza dei nuovi software numerici al fine di affrontare in maniera efficace anche le problematiche più ostiche e profonde. Il seminario “Progettazione delle strutture in materiale composito”, svolto il 21 ottobre a Verona nel contesto dell’”EnginSoft International Conference 2011”, è stata un’ottima occasione di ritrovo per tutti coloro che quotidianamente si ritrovano a dover affrontare tematiche complesse relative al mondo dei compositi; i consensi raccolti dimostrano che l’evoluzione del CAE, attraverso l’avvento di strumenti di prototipazione virtuale come ESAComp ed ANSYS Composite Prep/Post, ha generato un nuovo modo di concepire la fase di progettazione delle strutture, attraverso una sensibilità completamente rinnovata focalizzata all’efficienza computazionale, alla
drastica riduzione del time-to-market ed all’accuratezza dei risultati raggiunti. Il seminario è stato replicato il 4 novembre a Marina di Ravenna, nell’ambito dei “Seminari Nautilus” organizzati dalla Facoltà di Ingegneria dell’Università di Bologna. L’evento anche in questa occasione è stato seguito con particolare interesse da operatori del settore industriale, in particolare nautico, e della ricerca scientifica. La formazione avanzata sui nuovi software di simulazione per le strutture in composito rappresenta senz’altro un punto cardine per EnginSoft, che continuerà ad investire in eventi e seminari mettendo a disposizione competenze e strumenti CAE d’avanguardia. Per ulteriori informazioni: Fabio Rossetti, EnginSoft [email protected]
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EnginSoft presenterà la release 5.2 di MAGMA a METEF 2012 Il Metef, la fiera di riferimento per l’industria metallurgica, si terrà presso la Fiera di Verona dal 18 al 21 Aprile 2012. EnginSoft, come consuetudine, sarà presente con uno spazio espositivo in cui verranno presentate le nuove release dei sotware sostenuti relativi alla simulazione di processo, in particolare ci sarà la preview di MAGMA 5.2. A novembre 2009 è uscita la prima versione di MAGMA 5, la 5.0, che permetteva, in un ambiente completamente nuovo,
di affrontare virtualmente tutti i processi di fonderia basati su sabbia (ferrosi e non ferrosi). Con la versione 5.1, attualmente disponibile, sono stati integrati tutti i moduli, consentendo agli utenti di affrontare lo studio di tutti i processi di fonderia, dalla conchiglia in gravità alla bassa pressione, alla pressocolata in camera calda e in camera fredda ecc. Per i primissimi mesi del 2012 è prevista l’uscita della versione MAGMA 5.2. In questa versione sarà disponibile MAGMA C+M, un nuovo modulo, che permetterà di simulare la produzione delle anime con diversi tipi di leganti e di sabbie. Questo modulo consentirà di simulare la fase di riempimento delle casse d’anima e la fase di indurimento delle anime, permettendo di valutare le problematiche del processo produttivo e porvi rimedio con soluzioni correttive. MAGMA 5.2 consentirà inoltre, nell’ambiente di visualizzazione dei risultati (postprocessore), di confrontare direttamente simulazioni di differenti versioni permettendo di analizzare i risultati sia come singola immagine che come filmato in stato di avanzamento. Sarà possibile sincronizzare i filmati delle versioni a confronto per garantire una più semplice ed
efficace comparazione dei risultati selezionati. Grazie al tool “User Results”, presente nell’ambiente di visualizzazione dei risultati, sarà possibile elaborare nuovi criteri di valutazione, combinando i risultati forniti dal software. Tale procedura sarà resa possibile da un fornito compilatore matematico. Sarà infine possibile sfruttare la visualizzazione dei risultati sfruttando sistemi 3D, che permetteranno una visualizzazione in profondità dell’oggetto analizzato. MAGMA 5.2, come l’attuale versione 5.1, sfrutta la tecnologia Java, che permette un diretto interfacciamento con gli attuali sistemi operativi Linux e Windows a 64 bit, a garanzia delle più elevate performance di calcolo. METEF-FOUNDEQ, giunto alla nona edizione, rappresenta l'evento di riferimento per le tecnologie per l'alluminio e la fonderia. Grazie alle tante iniziative messe in campo, anche nel 2012 METEF-FOUNDEQ, attrarrà buyer da tutto il mondo interessati ad acquistare impianti, macchine, attrezzature per la produzione e la trasformazione dei metalli; componenti estrusi, colati e laminati; prodotti e materiali per il trattamento e la finitura. Per ulteriori informazioni: Piero Parona, EnginSoft [email protected] Sito web dell’evento: www.metef.com
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La simulazione di processo nella progettazione di radiatori Estetica e integrità di prodotto sono due fattori fondamentali per la produzione di radiatori, ma altrettanto importante è saper rispondere alle esigenze del mercato in tempi rapidi con costi competitivi. Il processo produttivo utilizzato per questo genere di produzione corrisponde alla colata in alta pressione. Tale processo, per le caratteristiche e i ridottissimi tempi di produzione dovuti all’iniezione forzata della lega negli stampi, richiede la massima precisione ed il controllo assoluto dei parametri imposti alle macchine da pressocolata. Per assolvere a queste richieste è fondamentale ridurre al massimo gli sprechi di produzione, comprimendo il più possibile i tempi di progettazione/realizzazione del prodotto. In questo contesto la progettazione prodotto/processo assume un ruolo di considerevole importanza: è infatti in questa fase molto delicata dove vengono valutate le soluzioni più efficaci per la realizzazione delle attrezzature ed i più adeguati parametri di processo. Sviluppare ed ottimizzare un processo produttivo significa identificare le variabili che maggiormente influiscono sulle caratteristiche del prodotto, valutandone gli effetti. Questo può essere perseguito attraverso un approccio al lavoro di progettazione che includa la simulazione di processo. Il caso che verrà proposto all’High Tech Die Casting 2012, che si terrà a Vicenza il 9 e 10 Febbraio 2012, riguarda la produzione di una specifica linea di radiatori progettati e prodotti dal Gruppo Ferroli. EnginSoft è stata coinvolta nell’attività di riprogettazione delle attrezzature al fine di ridurre al massimo gli scarti presenti nella linea produttiva, incrementando al massimo la qualità estetica e di tenuta del prodotto. Lo studio svolto ha avuto come obiettivo principale la ricerca del miglior sistema di colata per ottenere la massima qualità del componente e ridurre al minimo il rischio di inglobamenti d’aria, principale causa di scarto nel processo di pressocolata in produzione. La riprogettazione delle attrezzature ha inoltre permesso di incrementare la produttività e ridurre i costi. La collaborazione fra il Gruppo Ferroli ed EnginSoft ha determinato il successo del progetto, permettendo un rapido avvio della produzione. Per ulteriori informazioni: Giampietro Scarpa, EnginSoft [email protected]
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modeFRONTIER Users’ Meeting 2012
This year the International modeFRONTIER Users' Meeting 2012 (UM12), sponsored by ESTECO, will take place on 21st and 22 May 2012 at the Savoy Palace in Riva del Mandracchio Excelsior in Trieste. UM12 provides a unique forum to discover how engineering and academic experts apply the latest methods and techniques to optimize simulation design processes. The meeting of global significance has traditionally brought together experts from leading companies such as FIAT, Honda, Jaguar, Bombardier and many others. The issues relate to the operating logic of modeFRONTIER and its applications in different companies with high technological interest. ESTECO's biannual event is coming to its 5th edition, marking 10 years of exchange of best practices and ideas among modeFRONTIER enthusiasts. The leit-motiv of 2012 is Collaboration: nowadays sharing knowledge and team working are imperatives for any successful company. Technology helps breaking the barriers between disciplines, teams and field, encouraging knowledge sharing and enhancing working in team. It is not by chance that this concept is the main theme of the upcoming event, as modeFRONTIER provides a unique multidisciplinary software platform utilized in a wide range of fields all over the world. UM12 is not just a meeting of modeFRONTIER users, but it’s open also to the academic world: students and researchers are welcome to attend the event, and have the chance to look closely at industrial applications while getting the possibility to present in front of a knowledgeable audience. Guest of honor of the 2012 edition is David Edward Goldberg, the leading expert of genetic algorithms, although his expertise spans multiple disciplines. He has been Director of Illinois Genetic Algorithms Laboratory (IlliGAL) and Professor at the Department of Industrial and Enterprise Systems Engineering (IESE) of the University of Illinois. He will present two talks: one about collaborative engineering as part of the official UM12 agenda, and another one, open to the general public, concerning the relationship between higher technical education and society. For more information: http://um12.esteco.com/um12/
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EnginSoft GmbH Silver Sponsor at the ANSYS Conference & 29th CADFEM Users’ Meeting 2011 EnginSoft GmbH sponsored the ANSYS Conference and Users’ meeting, held this year at the Stuttgart International Congress Center. The ANSYS Conference focused on Electric Mobility Technologies, Machine Tools, Wind Energy Systems, Electronic Products Design, Building and Environmental design and Bio-Engineering Simulation.
that are difficult to combine when running aerodynamic shape optimization, although both the concepts are required to advance the transportation industry. High Speed Trains have to withstand the increasing efficiency requirements and emissions restrictions, hence major efforts are ongoing to innovate their aerodynamic design. In particular, train shape
The aim of the conference was to inform about the most recent methodologies for virtual prototyping and simulations. From 19th to 21st October, the Stuttgart International Congress Center hosted engineers and researchers from industry, research and education institutions, who shared best practices and recent outcomes from their simulation projects. The 29th ANSYS Users' Meeting started with a welcome speech by Jim Chashman (ANSYS CEO). The conference this year hosted over 1000 attendees, 200 technical presentations from Industrial Companies and Universities and 27 Technical Seminars. Thanks to the wide exhibition area available, the conference also gave the opportunity to engineers and ANSYS partners of a fruitful exchange of ideas. In addition to the more established engineering applications -like structural-mechanics, fluid-dynamics, electrical mechanics, a number of lectures and seminars focused on Engineering Systems Simulation and Optimization have been performed. Today, Engineering Systems like Car Engines, can be holistically simulated, accounting the physical and behavioral interactions between the subsystem parts. In the spirit of the conference, EnginSoft GmbH presented and time-lined an aerodynamic shape optimization process, presenting the paper “High Speed Train Aerodynamic Shape Optimization Methodology and Framework Comparison” [T. Newill - G. Buccilli, EnginSoft GmbH]. Train speed and aerodynamics efficiency are two concepts
contributes substantially to the overall aerodynamic performances. Typically, a 3D train design should guarantee an improved ratio between aerodynamic lift force and drag force with respect to reference designs. To pursue the High Speed Train aerodynamic optimization, EnginSoft GmbH proposed a methodology which used a baseline mesh model of the Train and a set of mesh-morphing control points. Then, instead of re-CADing and re-MESHing, the model was morphed using Arbitrary Shape Deformation algorithms. Finally, Latin Hypercube methods have been used to generate the Design Of Experiments and to identify the optimal Train Shape. To mesh-morph the Train model, EnginSoft GmbH used Sculptor™ software. Sculptor™ directly modifies any geometry or any mesh model, without using CAD or meshing tools. The software enables CFD analyses of different geometries in short time, without re-generating CAD geometries and meshes. This means that more design variations can be calculated in the same amount of time. Sculptor™ proved to be useful to find optimal High Speed
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Train design easier and quicker. Coupled with ANSYS-FLUENT, it allowed finding an improved train shape in just a few days, while with the traditional re-CAD and re-MESH approach, it would have taken several weeks. With subtle shape modifications, a sound 2% increase of overall lift/drag ratio and over 80% simulation time reduction was achieved – without affecting the overall geometry constraints. Sculptor™ avoided time consuming operations on the CAD model and on the computational grid, since the morphing took place over the ANSYS-FLUENT model directly. Besides the Train Aerodynamics optimization paper, at the 29th ANSYS Conference EnginSoft held a Seminar on “Product Design Chain Innovation thorugh Manufacturing Process Simulation” [N. Gramegna - Enginsoft Italy]. Today the whole product development chain can be simulated, from manufacturing process to thermalmechanical fatigue behavior and several CAE software are available for that purpose. More in particularly, the design of the manufacturing process (like casting, forging and machining) is gaining importance in product development, as all those processes directly impact mechanical properties and component behavior.
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During the seminar, EnginSoft presented innovative methodologies for Manufacturing Process simulation, all aimed at reducing product development time and resources needed. Nicola Gramegna gave the attendees an overview of the most relevant manufacturing processes, like Casting Process and Heat Treatment (simulated with the software MAGMASOFT), Forging (simulated with FORGE software) and Machining (simulated by the means of Advantedge software tools). Nicola showed how residual stresses-strains and local mechanical properties can be calculated through computer simulation. Finally, he showed how the non-uniform stressstrain and mechanical properties previously calculated, can be integrated into the FEM model (like ANSYS) to simulate the macro component behavior. For more information on Sculptor™: Giorgio Buccilli, EnginSoft GmbH [email protected]
SCULPTOR Sculptor is a powerful tool that allows a user to parameterize any mesh based on arbitrary cubic bezier control points. It can be linked to your existing fluid-flow (CFD) and/or structural (FEA) analysis tools and then deform these meshes and maintain quality in real time. Enabling the user to optimize a product without the need to remesh, saving you days, weeks, even months.
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BENIMPACT Suite has landed in China Dal 19 al 26 ottobre si è tenuto a Dalian, in Cina, il primo summit planetario sul basso impatto ambientale - Low Carbon Earth Summit (LCES 2011), che ha riunito esponenti della politica, della ricerca, delle tecnologie e pubblico con l’obiettivo di creare un tavolo intorno al quale scambiarsi le conoscenze oggi disponibili per riuscire a controllare l’impatto sul clima: “Spronare la green Economy per tornare in armonia con la natura”. Al “Forum 8: Clean Sciences and Technology for Low Carbon Environment - Today’s R & D, Tomorrow Industrial Revolutionization” di questo importante incontro è stato presentato anche il progetto CASA ZERO ENERGY, un edificio progettato e realizzato con un approccio “filosofico” che mira ad una visione integrata della sostenibilità. L’edificio, progettato dall’Università di Trento, è stato realizzato dal Gruppo Polo Le Ville Plus con il supporto della Regione Friuli Venezia Giulia. Numerose analisi di simulazione e ottimizzazione delle prestazioni energetiche ed ambientali sono state eseguite da EnginSoft con l’ausilio di BENIMPACT Suite. Portavoce dell’attività è stato il prof. Antonio Frattari, Responsabile Laboratorio Progettazione Edilizia (LPE) Direttore del CUnEd dell’Università di Trento. BENIMPACT Suite è il risultato di un progetto di ricerca cofinanziato dalla Provincia Autonoma di Trento - Legge Provinciale n° 6/99 Programma Operativo FESR 2007-2013 Obiettivo 2.
Last month, from 19th to 26th the first Low Carbon Earth Summit (LCES 2011) was held in Dalian, China. It brought together important politicians, researchers, and a large audience. The aim of this meeting was to create a round table where people could share their knowledge about controlling the environmental impact: “Leading the Green Economy, Returning to Harmony with Nature”. Prof. Antonio Frattari, the chief of Building Design Lab of the University of Trento, presented the project ZERO ENERGY HOUSE at “Forum 8: Clean Sciences and Technology for Low Carbon Environment - Today’s R & D, Tomorrow Industrial Revolutionization”. A philosophical approach towards integrate sustainability characterizes this building. The University of Trento has designed this house, Gruppo Polo Le Ville Plus has built it, and the local administration, Regione Friuli Venezia Giulia, has given its support. For the simulation of the building behavior BENIMPACT Suite has been used. BENIMPACT Suite is the outcome of a research project cofounded by the Autonomous Province of Trento (Italy) – Provincial Law n° 6/99 Operative Program FESR 2007-2013 Objective 2.
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CasaZeroEnergy can be called in this way because it has a very low energy consumption, it does not use any fossil fuels, and its energy demand is produced using renewable energetic sources. It anticipates the EU directive 31/2010/CE that requires the realization of near zero energy buildings, starting from 2020. The main features of CasaZeroEnergy are: • a strong bioclimatic characterization; • the use of natural, renewable and recycled materials for the construction of the building; • the development of a new and innovative timber frame system; • the set up of an intelligent system (home automation) to manage the energy consumption; • the integration with energy systems that use alternative and clean sources: photovoltaic plant of 14.6 kWh, solar thermal panels for DHW, horizontal geothermal plant with water – air heat pump integrated with a radiant floor heating and it can also work as a cooling system in summer. The building behavior has been simulated using BENIMPACT Suite and then compared with the real house behavior, which is monitored. Comparing the simulation with the monitoring results it is possible to observe some interesting things: • the performed simulation (with only two thermal zones) has been validated with the monitoring; • the building behavior is very good and it meets in a perfect way the expected predictions for summer. except from some temperature picks in the hottest days (June 29th and July 4th) the comfort in the house has been always achieved in the monitored period.
Alta Formazione: TCN punta ad una specializzazione sempre più avanzata Anche per l’anno 2012 il Consorzio TCN erogherà corsi di formazione specialistici e corsi a calendario. Continuerà l’attività di organizzare corsi personalizzati a seguito di specifiche richieste da parte dell’industria. A questi si aggiungeranno una serie di Minimaster con programmi formativi più intensi ed approfonditi rispetto a quelli dei corsi base ed avanzati. Per questo nuovo anno c’è anche l’intenzione di inserire corsi che trattano argomenti inediti di attuale interesse. Tutto sarà coordinato tra il Consorzio TCN ed i responsabili della formazione delle varie realtà lavorative. Per informazioni vi consigliamo di visitare il sito: www.consorziotcn.it oppure contattare la segreteria organizzativa: Mirella Prestini [email protected]
For more information: Angelo Messina, EnginSoft [email protected]
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CAE Seminars in Japan “CAE UNIVERSITY” Cybernet Systems Co.,Ltd. (with its headquarter located in Tokyo) has offered a wide range of leading-edge CAE solutions and services for many years since its establishment in 1985. Today, Cybernet sells more than 80 CAE products for diverse applications in mechanical, electrical and control engineering, optics, civil engineering and construction, optimization, bioengineering, nanotechnology and other sectors. To complement its software portfolio for its clients across Japan, Cybernet provides different types of services, such as technical support, training, and consultancy, to companies in manufacturing, as well as to universities and research institutes…and far more than this: The engineers of Cybernet are passionate about supporting MONOZUKURI in Japan, as one of the country’s leading CAE providers. The company’s corporate message states: “Energy for your Innovation”. To foster the interest in CAE and to support the next generation of CAE engineers, Cybernet developed and introduced an educational system called “CAE UNIVERSITY”. CAE University’s primary objective is to grow the use of CAE techniques among engineers. In Japan, the use of CAE technologies in manufacturing has expanded significantly in recent years. While we witness a growing interest in CAE, we also hear that many companies ask for additional support and know-how for improving their application skills and for making the use of CAE more efficient to solve their real problems. CAE UNIVERSITY is a new type of educational system which enables students to learn CAE systematically and continuously. It provides students with the necessary skills to use CAE technologies flexibly and efficiently for the actual requirements in their product design and development activities. Lectures and practical examples CAE UNIVERSITY offers both, 1-day or 2-day courses, in short periods, on each single topic in different fields. In lectures and hands-on sessions, participants study intensively theories of mathematics, physics and engineering, which are used in CAE today. By combining different courses, they are able to acquire theoretical knowledge in each field systematically. For example, by attending the 1.5 day lecture on
“Design and CAE Mechanics through Numerical Experiments“, the students learn many applications, from the basic numerical experiment and its theoretical consideration using beam and frame structure, to the modeling of solid structures, thermal stress and anisotropic materials. FEM Laboratory Nowadays, performing simulation by using CAE has become quite common in design and development departments. However, engineers sometimes are facing problems when simulation results differ from testing results. By performing testing and by comparing test results with simulation results in the FEM Laboratory, students can study and discuss the factors which sometimes lead to such errors. This helps them to understand the background and how the different steps and techniques are linked; they can now evaluate and verify simulation results correctly and make efficient use of them in their real design and development work. I had a pleasure to conduct the following interview with Mr. Takashi Sakurai, Manager of CAE UNIVERSITY. Please can you tell us about the positioning and the features of CAE UNIVERSITY? The main features of CAE UNIVERSITY are to offer the curriculum, which meets certain standards based on the University’s educational system and to invite active teachers from universities. The courses are linked with each other and the learning content has been examined carefully to avoid overlapping and insufficiency. Teachers who are in charge of the computational mechanics courses get together for
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curriculum meetings periodically, to check and modify the interaction of each lecture and practice. CAE UNIVERSITY can be regarded as a new CAE education system with a universitylike philosophy that offers high CAE knowledge levels. Concerning the content, some may think that mostly advanced CAE theory is being taught. The aim of CAE UNIVERSITY though clearly is not limited to the teaching of theory, it also provides the knowledge of advanced techniques of how to use CAE in the right way. Hence the theory is just an element of the teaching content. We believe that a combination of both: learning how to apply CAE and studying theory, will enable us to use CAE effectively for the actual job. Many companies have learned in the meantime that CAE is not a magical tool that will help just by introducing it. Introducing CAE also requires learning methods for its correct use. CAE UNIVERSITY is a reasonable system to learn techniques for CAE usage because it is systematic and continuous.
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about them. This means touching and trying shapes their imagination and deepens their understanding. Therefore, the “FEM Laboratory”, which offers a combination of lectures and testing is very effective. FEM Laboratory maintains a high reputation and gathers many registrations always. The size of testing is not so large, because it needs to be done on the desk. However, the testing is very well conducted and sufficient to understand the essence. Presently, we offer 2 FEM Laboratory courses, we are planning to add more in the future. Attending these courses, in which the students perform testing in groups, also provides a good platform for them to share information and to get to know each other and each other’s work easily. Often, students from different companies keep in touch afterwards and discuss their own problems with other engineers in similar environments.
What type of students do you have mostly? Many different types of employees participate. We welcome designers, R&D engineers, analysis specialists and trainers. We have students from universities too. They usually have different goals, for example reviewing things they have learned many years ago and solving specific problems on the job. We ask everybody who registers to complete a questionnaire before the course; we ask to tell us about requests, expectations and backgrounds. Teachers prepare and try to arrange the course as much as possible following the students’ satisfaction questionnaires. There is another questionnaire that is submitted after each course for future improvement of the courses. With these efforts, we are able to maintain good quality and to constantly gain reputation. The number of students who register for subsequent courses is rather high. Recently, we received several requests to hold on-site CAE UNIVERSITYs from customers who greatly appreciate the philosophy and the intent. Our clients more often book now on-site Courses and arrange for their engineers to participate in the entire range of lectures and practical sessions over months, to provide thorough CAE employee training.
Please tell us about your future vision for the “CAE UNIVERSITY” Currently, students need to come to our seminar room to attend CAE UNIVERSITY. This is difficult for someone who has to travel a long way or for those whose schedules are tight. To improve this, we are planning an alternative way of CAE education. Actually, we already have experiences in delivering the customized CAE UNIVERSITY on the customer’s intranet so that all their engineers can learn while being at work. By using cloud computing, the system can be applied and extended to a wider area and audience. We can indeed offer CAE UNIVERSITY to many more people. Also, if we develop other language versions, it will be possible to share this education system globally. We want to achieve new CAE oriented design innovation by collaborating with as many engineers as possible who have studied and overcome engineering challenges. To reach this goal, we want to build a CAE community, to foster comprehensive CAE development in Japan and in other countries around the world. This is our ultimate vision and goal.
What is the students’ general reaction to the “FEM Laboratory”? CAE is a tool for design. Designers have got into the habit of doing, looking at and touching real things and thinking
This article has been written in collaboration with CYBERNET SYSTEMS Co.,LTD.: http://www.cybernet.co.jp/english/ Akiko Kondoh, Consultant for EnginSoft in Japan
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NPO Activity for Implementation of Anisotropic Elasto-plastic Models into Commercial FEM Codes The nonprofit organization JANCAE, The Japan Association for Nonlinear CAE (chairperson: Kenjiro Terada, Tohoku University), offers several activities to companies, universities and software vendors [1] to gain a deeper understanding of nonlinear CAE including its main work, the nonlinear CAE training course held twice a year. This article introduces JANCAE’s efforts to implement anisotropic elasto-plastic models into commercial FEM codes as one of the initiatives of the “Material Modeling Committee”. 2. Background and outline 2.1 The efforts of the Material Modeling Committee: When we think of comprehensive advancements in the accuracy of a simulation, we are aware that all capabilities of the material modeling, the boundary conditions as well as the definition of the geometric modeling have to be improved at the same level. The capabilities of geometric modeling for FEM simulations have drastically improved along with the growth of the 3D CAD market, the advancements in auto-meshing capabilities and the progresses made in hardware speeds and capacities, over the past 10 years. Yet material modeling capabilities have not progressed as significantly as the advances achieved in geometric modeling. Users need to be involved in the definition process of material modeling, which means that they have to choose the appropriate material model from huge amounts of available material models offered by each FEM code. As a next step, the parameters of the material properties have to be determined by performing material tests. These processes are still necessary, even now, at a time when many sophisticated commercial FEM codes are available. In this situation and independently from its CAE training course, which mainly consists of classroom lectures, JANCAE organizes “The Material Modeling Committee” as a practical approach to the study of nonlinear materials. The Committee was originally established in 2005 to study mainly hyperelasticity and viscoelasticity. Then, its research activities have diversified into all material nonlinearity including metal plasticity. In the frame of the Committee, members learn about typical nonlinear material modeling by studying the basic theory of the constitutive equations, material testing methods, and how to handle test data and parameter identification techniques. 2.2 User subroutines for constitutive law in FEM Codes There are many constitutive equations of materials, as we can see from the many researchers’ names which appear in the titles of the equations. Although such variety of material models contributes to the improvement of simulation accuracy, not all material models, especially new models, can be applied
to various commercial FEM codes. With regard to yield functions, which are a core concept for metal plasticity, it has been pointed out that the yield surfaces of the actual metal materials cannot be represented well enough by the classical anisotropic yield functions [2]. However now, many different types of new yield functions are proposed especially in sheet metal forming; they are able to represent real plastic deformation much better than before [3]. LS-DYNA provides specific capabilities for sheet metal forming simulation, it also offers a considerable number of new anisotropic yield functions [4]. On the other hand, when we think about other commercial general purpose FEM codes, they usually have only limited kinds of yield functions, such as the classical Hill quadratic anisotropic function. These commercial codes offer user subroutine capabilities to extend material models. By using these capabilities and defining material models following the programming rules that each code provides, users can implement the required constitutive laws. However in reality, it is difficult for ordinary users who are not familiar with the framework of continuum mechanics, numerical simulation and the theory of plasticity, to perform such processes only from released text books or available information, as the manual definition in FEM codes requires professional skills. 2.3 The development activity in the Material Modeling Committee The Material Modeling Committee started its unique R&D activity in 2009. For this activity, engineers with various backgrounds and skills engaged in the CAE field got together to jointly work on making subroutines for the constitutive laws. The members are from industrial companies and CAE software vendors. As mentioned above, it is impossible to create such subroutines without understanding the basic concept of elastoplastic models for FEM. In the first year, in 2009, we studied the basics of plastic constitutive equations and the framework
Fig. 1 - Framework of the subroutine “UMMDp”
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of constitutive law subroutines by referring to some text books [5], to obtain a better understanding of their principles. In parallel, we summarized the characteristics of each code’s user subroutine and proposed a framework for the user subroutine development. [Fig.1] In this framework, stress integration and calculation of consistent tangent modulus, which represent basic capabilities of constitutive law subroutines, have been determined as “Unified Material Model Driver for Plasticity (UMMDp)” and separated from each code’s specified rule in order to be able to be used commonly. Additionally, yield functions were isolated as a modularized subroutine so that we can implement different types of yield functions easily. In the second year, in 2010, the members worked on the programming based on this framework and by sharing each role. 3. Development and verification of the user subroutine 3.1 Basic equations of elasto-plastic constitutive laws Here we show the basic part of the subroutine for elasto-plastic constitutive laws, which is crucial for this programming. Tensor is represented by the Voigt notation arraying components as vector. The stress to be calculated is , and the strain increment given to the subroutine is . Following are basic equations for elasto-plastic constitutive laws. (1) (2) (3) (4) (5)
Equation (1) shows the yield condition and represents that stress point on the yield surface. The shape of the yield surface is determined by the yield function , the magnitude is given by the hardening curve showing isotropic hardening and the center of the yield surface is provided by the back stress showing kinematic hardening respectively. Equation (2) shows that the elastic and the plastic strain increments are given by additive decomposition, and the elastic strain increment gives the stress increment by Hooke’s law shown as Equation (3). Equation (4) gives the plastic strain increment and here the associated flow rule is used, in which the outward normal of the yield surface and the plastic strain increment have the same direction. Equation (5) is the evolution equation of the back stress. p shows the equivalent plastic strain which has a conjugate relation with the equivalent stress in the plastic work. UMMDp uses backward Euler’s method for the stress integration algorithm. In this method, nonlinear simultaneous equation is solved, assuming the stress and internal variable (back stress and equivalent plastic strain pn+1) after the completion of ”n+1” increment satisfy the basic equations (1) – (5). We now define residual functions as follows. (6) (7) (8)
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Now is the trial stress (initial estimate of stress integration) assuming all strain increments are elastic components and given by
Equation (6), Equation (7) and Equation (8) correspond to the yield condition of Equation (1), Equation (2) – (4) and the back stress evolution equation of Equation (5) respectively, and the stress after integration and the internal variable ( and ) are obtained by converging , and to 0 using Newton-Raphson method. In UMMDp, it is predicted that the convergence calculation will be difficult because of implementation of higher order anisotropic yield functions. So we relaxed the condition of (6) by using Multistage Return Mapping [6] which leads to gradual convergence. 3.2 The idea of UMMDp The variables used for convergence calculation of the stress integration are the yield function , the isotropic hardening curve , the back stress evolution equation and their first and second order differentials. In the static implicit method, tangent matrix (Material Jacobian) consistent with stress integration algorithm, is also required to obtain the quadratic convergence in equilibrium calculation. In this calculation, as with the stress integration, yield function, isotropic hardening curve, back stress evolution equation value and its differential value are going to be needed. The frameworks of calculation for stress integration and consistent tangent modules are in common regardless of forms of yield function, hardening curve and back stress evolution equation. Therefore, if we could make a unified interface for those various sets of functions, the function group of a variety of constitutive equations described above would be able to be modularized and have higher expandability. When we think about the variable names and the stored formats in subroutines of commercial codes, of course they vary from code to code. However, the role of the constitutive law in FEM codes is to provide “local stress-strain relation at integration point” and there is no difference on this point. By using proper variable conversion for code-independent user subroutines, they can be linked to UMMDp correctly. From this standpoint, the great variety of constitutive equations, such as yield function and hardening law can be externalized. Additionally, if we develop the interface for different commercial codes using their specific user subroutines, which we call “Plug”, it will kick-off an open effort and a discussion which will not be limited to a specific code. 3.3 Yield function subroutine The yield function subroutine is developed mainly by CAE users from industrial companies. Following are the yield functions for the implementation. (von Mises is used for verification of the implementation.) von Mises[7] Hill(1948[8], 1990[9])
48 - Newsletter EnginSoft Year 8 n°4 Gotoh's bi-quadratic yield function [10] Barlat yield function (Yld89[11], Yld2000[12], Yld2004[13]) Banabic yield function (BBC2005[14], BBC2008[15]) Cazacu 2006[16] Karafills & Boyce[17] Vegter[18] The yield function subroutine receives the stress component as the argument, and then returns the corresponding equivalent stress , its first order differential and its second order differential . To demonstrate objectively that the developed subroutine works correctly, also numerical verification is being performed. For this verification, we also provide a main routine so that only the capability of the yield function’s subroutine itself can be checked separately without mixing up its bug with other bugs in UMMDp (the parent routine of the yield function’s subroutine), and “Plug” for commercial FEM codes. By doing so, the members can work independently. The verification was performed by the comparison between the yield surface in the original paper, which proposed anisotropic yield functions, and the output from our developed subroutine as shown in Fig.2, as well as by the comparison between analytical and numerical differential values to secure correctness. 3.4 Development of the interface “Plug” for commercial codes The “Plug” subroutine, which becomes an interface to commercial FEM codes, is developed mainly by engineers from CAE software vendors. This subroutine links to UMMDp correctly through each different manner depending on commercial codes. The name of the ‘Plug’ is based on the functional analogy of plug-adopter for AC power socket which differs by nation. The Plug needs to offer overall capabilities for communication with commercial codes, such as storing and updating internal variables, and variable output adjustment to result data. On this point, it was very helpful to gain the cooperation of engineers from software vendors, who are familiar with each commercial code. We appreciated their cross-border cooperation. The verification of the developed Plug was also performed. For this verification, we used the basic benchmark test provided by the NAFEMS guidebook [19] for “Code to Code Verification”. We
(a) Yield locus in original paper [12]
(b) Output from ummdp_checkyf
Fig. 2 - Verification of yield function subroutine (eg:Yld2000).
compared the result using default elasto-plastic models prepared in each commercial code (von Mises type isotropic yield functions) and the result using the von Mises type yield function through UMMDp, and we confirmed that these stress histories are matching as shown in Fig.3.
Fig. 3 - Comparison with result of commercial code (von Mises model)
3.5 Implementation of combined hardening law We finalized the development and the verification of the program for the standard isotropic hardening models in 2009. It is difficult to simulate deformation behavior accurately when the direction of stress is reversed. So we are promoting the development of the combined hardening model including kinematic hardening shown in the basic equations. Kinematic hardening behavior is modeled by back stress evolution equation. For this evolution equation, various types of models are proposed, and we need to accept this diversity as with yield functions. At this point in time, we are developing a framework to modularize the function shown in Equation (5) as a subroutine. 3.6 Total verification For total verification of the developed program, we analyzed problems which come to the surface by the influence of plastic anisotropy, and we compared them to the reliable result. We simulated a hole-expansion test of a steel sheet [20] and a hydraulic bulge test of aluminum alloy [21] in cooperation with Prof. Kuwabara, Tokyo University of Agriculture and Technology. Fig.4 shows the simulation result of the holeexpansion test. We can see that the thickness decrease around the center hole varies with angle from the rolling Fig. 4 - Simulation example of holeexpansion test direction. Afterwards, we verified that the developed subroutine group worked rightly, by comparing the UMMDp simulation result and the reliable simulation result. The aim of the verification at this stage is not the comparison with experimental results, instead it is absolutely for Code to Code Verification. We think that using the middle scale problem, which is positioned between small scale problems like material testing and large scale problems in realistic sheet metal forming, is more important for the material model validation rather than jumping to a complicated large scale problem. 4. Closing In this article, we introduced an activity of the NPO “JANCAE” working group. As the volume of tasks becomes larger, the development is still in progress. In 2011, the development of a common subroutine for resin and rubber has been planned as a subsequent activity of the working group. The effort this
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time is the implementation of the yield functions which were already proposed in previous papers, hence there is no academic novelty. Meanwhile, it is not just about a limited activity for a specific commercial code only. This is why the topic is not really suitable to be presented in academic societies or at specific users’ conferences by CAE vendors. We introduced this work as an example of the activities featuring NPO’s neutrality. Following NPO’s guidelines, it is planned that the subroutine group will be opened to the public a year after activity completion. Yet more than 30 engineers from different organizations have already joined the working group. Their backgrounds are different, some have already obtained permissions from their managers, some join to support their own personal development. In any case, their motivation is the most important driving force for the activity. C.A Coulomb, when he was a building engineer in the military corps of engineers, expressed the reason to write a paper by making an analogy to an artisan when he submitted the paper to the French Académie des sciences in 1773, as follows.[22] “Besides, the Sciences are monuments consecrated to the public good. Each citizen ought to contribute to them according to his talents…. While great men will be carried to the top of the edifice where they can mark out and construct the upper stories, ordinary artisans who are scattered through the lower stories or hidden in the obscurity of the foundations should seek only to perfect that which cleverer hands have created.” We think the reason why so many engineers were eager to be involved in the work is because of their motivation to understand in a deeper way and to express their sympathy for the activity based on Coulomb’s words. We, ordinary artisans, have great responsibility in the present apprehensions regarding the gap between computational mechanics and CAE [23]. 5. References [1] http://www.jancae.org/ [2] The Japan Society for Technology of Plasticity ed.: StaticImplicit FEM – Sheet metal forming (process simulation series), Corona Publishing, pp.198, 2004. (in Japanese) [3] ibid. pp.172. [4] LSTC, JSOL: LS-DYNA Version 970 User’s Manual Vol.2, 2003. [5] F.Dunne, et al.: Introduction to Computational Plasticity, Oxford Univ. Pr., 2005. [6] J.W.Yoon, et al.: Elasto-plastic finite element method based on incremental deformation theory and continuum based shell elements for planar anisotropic sheet materials, Comp. Meth. Appl. Mech. Engrg., vol.174, pp.23-56, 1999. [7] R.von Mises: Mechanik der festen Körper in plastischendeformablem Zustand, Göttinger Nachrichten math.-phys. Klasse, pp.582, 1913. [8] R.Hill: A theory of the yielding and plastic flow of anisotropic metals, Proc. Roy. Soc. A: vol.193, pp.281, 1948. [9] R.Hill: Constitutive modeling of orthotropic plasticity in sheet metals, J. Mech. Phys. Solids, vol.38, no.3, pp405417, 1990.
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[10] M.Gotoh: Improvement of orthotropic theory by implementation of forth order yield function (plane stress) I, JSTP journal, vol.19, no.205, pp.377-385, 1978. [11] F.Barlat, et al.: Plastic behavior and stretchability of sheet metals. Part-I, Int. J. Plasticity, vol.5, pp.51-66, 1989. [12] F.Barlat, et al.: Plane stress yield function for aluminum alloy sheet: part 1:theory, Int. J. Plasticity, vol.19, pp.1297-1319, 2003. [13] F.Barlat, et al.: Linear transformation-based anisotropic yield functions, Int. J. Plasticity, vol.21, pp.1009-1039, 2003. [14] D.Banabic, et al.: Influence of constitutive equations on the accuracy of prediction in sheet metal forming simulation, Proc. of NUMISHEET2008, 2008. [15] D.Banabic, et al.: Plane-stress yield criterion for highlyanisotropic sheet metals, Proc. of NUMISHEET2008, 2008. [16] O.Cazacu, et al.: Orthotropic yield criterion for hexagonal closed packed metals, Int. J. Plasticity, vol.22, pp.11711194, 2006. [17] A.P.Karafillis, M.C.Boyce: A general anisotropic yield criterion using bound and a transformation weighting tensor, J. Mech. Phys. Solids, vol.41, no.12, pp.18591889, 1993. [18] H.Vegter, et al.: A plane stress yield function for anisotropic sheet material by interpolation of biaxial stress states, Int. J. Plasticity, vol.22, pp.557-580, 2006. [19] A.A.Becker: Understanding Non-linear Finite Element Analysis Through Illustrative Benchmarks, NAFEMS, pp.20, 2001. [20] Kuwabara, T., Hashimoto, K. Iizuka, E. and Yoon J.W., Effect of anisotropic yield functions on the accuracy of hole expansion simulations, J. Mater. Processing Technol., 211 (2011), 475-481. [21] Daisaku Yanaga, Toshihiko Kuwabara, Naoyuki Uema and Mineo Asano: Material Modeling of 6000 Series Aluminum Alloy Sheets with Different Density Cube Textures and Effect on the Accuracy of Finite Element Simulation, Proc. NUMISHEET 2011, Seoul, Korea, 21-26 August, 2011, pp.800-806. (AIP Conference Proceedings, Volume 1383) [22] Timoshenko, S.P.: History of Strength of Materials, Dover publications, pp.47, 1983. [23] N.Kikuchi: Computational Solid Mechanics –Trend and Future, JSCES Journal, vol.11, no.1, pp.1290-1295, 2006. (in Japanese) Hideo Takizawa (Mitsubishi Materials Co, Japan) Vice-chairman of JANCAE Material Modeling Committee For more information about this article, please e-mail: [email protected]
By courtesy of Mechanical Design & Analysis Corporation, an original version of this article was presented at the 4th Mech D&A Users’ Conference, 1 July 2011 (Tokyo, Japan) and published in the Conference Proceedings.
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EnginSoft Event Calendar ITALY For more information on the next EnginSoft Seminars and Webinars, please contact: [email protected] Stay tuned to: www.enginsoft.com (Events) Download the 2011 Conference Proceedings now on: www.enginsoft.com/proceedings2011 and stay tuned for the dates/venue of the 2012 International Conference: www.caeconference.com Every year, the conference program features applications of CAE in: mechanics, industrial applications, structural engineering, optimization, manufacturing process simulation, computational fluid dynamics, emerging technologies, durability and fatigue, rapid and impact dynamics, CAD/CAE integration, … 9-10 February - High Tech Die Casting, Vicenza EnginSoft will present a case history of the process simulation applied to Ferrioli radiators. www.metallurgia-italiana.net 18-21 April - METEF 2012, Fiera Verona EnginSoft will present the MAGMA 5.2 release. www.metef.com 15th European Conference on Composite Materials. 24-28 Giugno; Venezia. www.eccm15.org. 3rd Dolomites Workshop on Constructive Approximation and Applications; 9-14 Settembre; Canazei events.math.unipd.it/dwcaa2012/?q=node/1 GERMANY 15-16 November - NAFEMS European Conference: Simulation Process and Data Management (SDM). Munich If you would like to hear more about EnginSoft Germany’s presentation on: Methodology and Validation for Bidirectional, Homogeneous Simulation Data Flow Management in a Fluid-Structure Interaction Problem Utilizing Workflow Management and Shape Deformation Tools, please contact our team at: [email protected] EnginSoft Germany. Regular Webinars and On-site Presentations 2011 & 2012: EnginSoft Germany hosts regular Webinars to present the company’s products and services, as well as specific Webinars to discuss our customers’ current applications and needs. To hear more and to fix an appointment for your company,
please contact: [email protected] Please stay tuned to: http://www.enginsoft-de.com/ FRANCE Flowmaster Roadshow 2012 Pour accompagner le lancement de Flowmaster V7.9 et présenter ses principales nouveautés, Enginsoft France organise des conférences dans plusieurs villes de France. Vous y découvrirez notamment l’analyse diphasique, le temps réel, et le couplage avec modeFRONTIER. Inscrivez-vous vite! Book your place now, for the Conferences that EnginSoft France will host in 2012 – Hear about Flowmaster V7.9 and the coupling with modeFRONTIER! Voici les lieux et dates – Dates & venues: • 2 février 2012 après midi à Nantes • 7 février 2012 après midi à Lyon • 9 février 2012 après midi à Toulouse • 14 février 2012 après midi à Aix en Provence • 16 février 2012 après midi à Paris Pour vous inscrire, appelez vite le +33 (0)1.41.22.99.30 ou visitez http://www.enginsoft-fr.com/ EnginSoft France 2011 & 2012 Journées porte ouverte dans nos locaux à Paris et dans d’autres villes de France, en collaboration avec nos partenaires. Pour plus d'information visitez: www.enginsoft-fr.com, contactez: [email protected] UK The workshops are designed to give delegates a good appreciation of the functionality, application and benefits of modeFRONTIER. The workshops include an informal blend of presentation plus ‘hands-on’ examples with the objective of enabling delegates to be confident to evaluate modeFRONTIER for their applications using a trial license at no cost. modeFRONTIER Workshops Warwick Digital Laboratory, Warwick University • Thursday 10th March • Tuesday 12th April • Tuesday 21st June • Wednesday 17th August • Tuesday 1st November • Wednesday 14th December modeFRONTIER Workshops at Warwick Digital Laboratory, Warwick University
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Thursday 10th March Tuesday 12th April Tuesday 21st June Wednesday 17th August Tuesday 1st November Wednesday 14th December
modeFRONTIER Workshops at Cranfield University • Thursday 27th May modeFRONTIER Workshops for InfoWorks CS at Warwick Digital Lab • Tuesday, 8th February • Thursday 26th May • Wednesday 20th July • Thursday 13th October • Tuesday 22nd November To register, please visit: www.enginsoft-uk.com 7th December - CIWEM Innovations Showcase, Coventry EnginSoft has been selected to present 'Exploring the full range of possible solutions to DG5 schemes by combining modeFRONTIER's smart algorithms with InfoWorks CS maximising customer choice between performance and cost' http://bit.ly/InnSC SWEDEN 2011 Training Courses on modeFRONTIER – Drive your designs from good to GREAT EnginSoft Nordic office in Lund, Sweden The Training Courses are focused on optimization, both multi- and single-objective, process automation and interpretation of results. Participants will learn different optimization strategies in order to complete a project within a specified time and simulation budget. Other topics, such as design of experiments, meta modeling and robust design are introduced as well. The two day training consists of a mix of theoretical sessions and workshops. The following dates are scheduled for 2012. All courses are held at the EnginSoft Nordic office in Lund, Sweden. • 1st-2nd December • 25-26th January • 8th-9th February • 6th-7th March • 2nd-3rd April • 3rd-4th May • 5th-6th June • 4th-5th September • 3rd-4th October • 6th-7th November • 6th-7th December To discuss your needs, for more information and to register, please contact EnginSoft Nordic, [email protected]
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SPAIN EnginSoft Iberia. Programa de cursos de modeFRONTIER and other local events. To enquire about the next events in Spain and for more information, please contact: tel: +34 938.945.092. email: [email protected] Stay tuned to: http://iberia.enginsoft.com/empresa El 14 de diciembre de 2011 a las 09:30 Webcast: Add-On para LabVIEW de modeFRONTIER para la Optimización de parámetros y Prototipado Rápido de Control El 20 de diciembre de 2011 a las 10:00 (45 minutos) Webcast: Metodologías que aumentan su valor añadido a sus clientes For more information on the 2 Webcasts, please visit: http://www.aperiotec.es/agenda.php USA TMS 2012 Annual Meeting & Exhibition; 11-15 March; Orlando. www.tms.org/meetings/annual-12/AM12home.aspx Courses and Webinars on Design Optimization with modeFRONTIER Sunnyvale, CA. For more information, please contact: [email protected] www.ozeninc.com ISRAEL AUVSI; 20-22 Marzo; Tel Aviv event.pwizard.com/auvsi2012/index.py?p=376 EUROPE, VARIOUS LOCATIONS modeFRONTIER Academic Training Please note: These Courses are for Academic users only. The Courses provide Academic Specialists with the fastest route to being fully proficient and productive in the use of modeFRONTIER for their research activities. The courses combine modeFRONTIER Fundamentals and Advanced Optimization Techniques. For more information please contact: modeFRONTIER University Program, [email protected] To meet with EnginSoft at any of the above events, please contact us: [email protected]
Corsi di addestramento software 2012 L'attività di formazione rappresenta da sempre uno dei tre maggiori obiettivi di EnginSoft accanto alla distribuzione ed assistenza del software ed ai servizi di consulenza e progettazione. Per ciascuno dei possibili livelli cui la richiesta di formazione può porsi (quella del progettista, dello specialista o del responsabile di progettazione), EnginSoft mette a disposizione la propria esperienza per accelerare i tempi del completo apprendimento degli strumenti necessari con una gamma completa di corsi differenziati sia per livello (di base o specialistico), che per profilo professionale dei destinatari (progettisti, neofiti od analisti esperti). La finalità è sempre di tipo pratico: condurre rapidamente all'utilizzo corretto del codice, sviluppando nell'utente la capacità di gestire analisi complesse attraverso l'uso consapevole del codice di calcolo. Per questo motivo ogni corso è diviso in sessioni dedicate alla presentazione degli argomenti teorici alternate a sessioni 'hands on', in cui i partecipanti sono invitati ad utilizzare attivamente il codice di calcolo eseguendo applicazioni guidate od abbozzando, con i suggerimenti del trainer, soluzioni per i problemi di proprio interesse e discutendone impostazioni e risultati. Anche per il 2012 EnginSoft propone una serie completa di corsi che coprono le necessità di formazione all'uso dei diversi software sostenuti. Le novità proposte, confermano l’idea che EnginSoft ha della formazione: non è una realtà statica che si ripropone uguale a se stessa di anno in anno, ma è un divenire, guidato dall'esperienza accumulata negli anni, dall'evoluzione del software e dalle esigenze delle società che si affidano a noi per la formazione del proprio personale. In tale contesto EnginSoft organizza e sviluppa anche attività didattiche attraverso un programma formativo personalizzato, soluzioni di progettati in relazione alle necessità e alle specifiche esigenze aziendali del committente. L’offerta dei corsi ANSYS viene ridefinita ogni anno per adeguarsi, sia all’evoluzione del software ed alle caratteristiche dell’ultima versione disponibile, che all’introduzione di nuovi moduli e solutori. In tale senso si segnala in campo fluidodinamico l'introduzione, accanto ai corsi tradizionalmente erogati, del corso ANSYS FLUENT: Corso Avanzato sulla Combustione. Sono stati inoltre rivisti ed aggiornati i corsi relativi a tutti gli altri software sostenuti da EnginSoft per adeguarli allo stato attuale delle relative distribuzioni.
Si segnala infine l'introduzione del nuovo corso DIGIMAT, modellatore avanzato, non lineare, multi-scala di materiali che si pone come obiettivo quello di offrire una rappresentazione completa e rigorosa utile sia ai fornitori di materiali (“progettisti” di materiali), sia ai progettisti analisti CAE (end users) per i quali, il più delle volte, il materiale viene modellato in modo semplificato. Dal punto di vista organizzativo nel 2012 tutte le sei sedi EnginSoft saranno impegnate nella formazione, dando la possibilità agli utenti di scegliere la location a loro più conveniente in termini di vicinanza geografica alla propria società. Tutto questo a riprova dell'impegno nella formazione che, per EnginSoft, è e rimane un punto fondamentale della politica aziendale, un impegno costante verso l'eccellenza, un servizio per fare crescere i suoi clienti e, se lo desiderano, crescere con loro. Per maggiori informazioni: www.enginsoft.it/corsi Per richiedere una copia del libretto: [email protected]
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