Tuesday 29 October 2019 14.30 - 17.30 Language: English
Aerospace & Defense Session
Emmanuel Leroux, Dassault Systemes
Simulation of the Effects of direct lightning strike on an aircraft managed in a collaborative environment that connects Simulation Roles to Mechanical CAD, Cable harness CAD and PLM.
This presentation focuses on the simulation of Electromagnetic Environmental Effects (E3) and in particular direct lightning strike on an aircraft. The coupling on cables inside the aircraft is simulated with a 3D-2D EM/circuital EM approach so that the currents induced on inner conductors connected to attached loads are predicted. Modern aircraft often use advanced composite materials due to their superior mechanical properties. However, they are significantly less electrically conductive than traditionally used aluminum. Therefore layer of conductive fibers or screens designed to carry lightning currents are embedded in the composite stack up. In this talk the effects of the high current flowing on the fuselage onto the Lightning Struck Panel Breakage Under Compressive Load is shown. Then a video is commented where the Simulation task is defined by the Project Manager in a Collaborative space where stakeholders are identified and project duration is fixed. The analyst is then alerted to make the analysis starting from a CAD file he can easily located using a 6WTags approach. The Electromagnetic model is then prepared including the sources, boundary conditions, scenario and saved for future usage. After visualization of the results a what-if analysis is done moving the end point of the cable. The Harness designer makes the change and automatically the Electromagnetic model gets updated, saving lots of time. At the end results for the 2 cable configurations are presented in smart way using a Viewer usable on a Tablet the Project Manager can bring in a meeting to finally decide on the best action to take.
Francesco Di Caprio, CIRA
Design and Optimization of metallic lattice structures for Additive Manufacturing
The present work aims to describe a novel numerical tool developed for the structural optimization of metallic lattice structure. The implemented structures consisting in an outer skin, an internal lattice structure, and a potential inner skin useful to model structure with internal cavities. The optimization procedure involves two commercial software: ANSYS and ModeFrontier. The first one is dedicated to pre and post-process activities, while the second one is dedicated to the optimization flow management. In order to reduce the computational cost, the tool models the structure by means of simplified element: shells and beams. Nevertheless, at the end of the optimization process, the tool generate automatically a full 3D model, that can be exported in a CAD format and just ready for the manufacturing process. The tool was used to design several axial-symmetric lattice structures under compressive static loading conditions. A specific test case was manufactured (using the EBM technology) and validated experimentally. The presented test case aims to underline the advantage in using such kind of structures to improve the performance of slender structures.
Denis Feindt, Synopsys
Hadass R. Jessel, Augmanity Nano Ltd & Bar-Ilan University
Ido Bachelet, Augmanity Nano Ltd
Sagi Chen, Technion - Israel Institute of Technology
Shmuel Osovski, Technion - Israel Institute of Technology
Daniel Rittel, Technion - Israel Institute of Technology
Sol Efroni, Bar-Ilan University
3D Scans to Avian Nests: Solving Simulation Challenges with Image-Based Modelling
CAE models generated from 3D image data enable analysis of complex artificial and natural structures. These models also provide a valuable resource for non-destructive inspection, for example of defects and microstructural details. In this presentation, we will discuss some of the current techniques in image-based modelling and simulation, and how they are being applied by innovative success stories.
Bird nests offer one excellent example of using image-based simulation to approach engineering challenges. A workflow using Synopsys Simpleware software generated models of edible-swiftlet nests from micro-CT and involved segmentation and export of Finite Element (FE) models for simulation in Abaqus. This work looked at how the production of nests has similarities to Additive Manufacturing through mechanical overdesign of an optimized structure for handling stress, as well as showing how complex structures can be built using local or self-produced materials.
Tamas Turcsan, eCon Engineering
Laszlo Kovacs,eCon Engineering
Laszlo Takacs, eCon Engineering
Innovation Driven Composite FEM Solutions at eCon Engineering
This paper is to expound the practical experience fueled and market tendencies driven innovation at eCon Engineering Ltd. These activities mostly connected to mechanical finite element method-based calculations of fiber reinforced polymer composites. These solutions have large spectrum but this article focuses on the characterization of ply-level properties and failure criteria from simple material tests and layer build-up optimization of composite structures. Using these methods more efficient composite structures can be designed and produced via better cost-performance trade-offs. The newly developed methods lead us to the better understanding of design principles and possibilities of these materials and allow us to expand the spectra of our engineering services as well.
15.50 - 16.20
Vangelis Palaiokastritis, BETA CAE Systems
Eleftherios Tsivolas, BETA CAE Systems
Non Linear Multi-scale Modeling of Composites
The scope of this presentation is to demonstrate a workflow for the Multi-scale modelling of structural components made with Composite materials in ANSA environment. Taking advantage of ANSA Homogenization Tool and Results Mapper the user is able to bridge the gap between process simulation and structural analysis and automatically generate a model for the examination of the microstructural behavior of the composite.
The aim of this case study was to substitute the metallic (aluminum) material of a beam, subjected into 3-points bending, with a Short Fiber Reinforced Polymer (Carbon/Epoxy) to reduce its weight. With known properties of the constituents, a material with equivalent response was estimated for both the elastic and plastic regions, using Mean Field Homogenization formulations. Afterwards, the fiber orientation from the molding simulation was mapped in the structural model. Both models (metallic and composite) ran in the nonlinear regime resulting in almost identical flexural behavior. Furthermore, the high strain area of the model was isolated and a FE-model for the Representative Volume Element (RVE) was automatically generated in ANSA based on given microstructure information and orientation tensor from the molding analysis. The RVE model was subjected into the boundary conditions (strain) of the macro-scale analysis to examine cases of fiber-matrix interfacial damage.
Finally, the beam made by the Composite Material had approximately half of the weight of the aluminum beam. Although in case of the aluminum and composite beam the material response did not exceed the plastic region, in microscale level fiber-matrix debonding was observed at the end of the analysis.
Stefano Carrino, University of Salento
Gennaro Scarselli, University of Salento
Stefano La Rovere, NIER Ingegneria
Modeling of Lamb waves using ANSYS
Guided waves are considered as one of the most encouraging tools for quantitative and qualitative identification of defect/damage in metallic and composite structures. Among these, Lamb waves can be excited in plate-like thin plate with parallel free boundaries, they can travel over a long distance even un materials with high attenuation ratio and have a high sensitivity to interference on a propagation path. For these reasons, Lamb waves can be exploited to quickly inspect a broad area so allowing for a structural monitoring. In this work, the propagation properties of Lamb waves were analytically calculated solving the transcendental Rayleigh-Lamb equation in Matlab. The propagation of Lamb waves in a isotropic plate was studied by Finite Element Method in Ansys. Coupled field transient analyses were carried out in order to simulate the action of PZT disks bonded onto the structure and to understand the mechanism of different mode excitation. The FE models were validated and calibrated by experimental campaigns.
Brian C. Munguía, Stanford University
Walter T. Maier, Stanford University
Goal-Oriented Mesh Adaptation for Hypersonic Nonequilibrium Flows
Mesh adaptation is now common practice in the CFD community for performance verification. Most of such efforts have been focused on posteriori error estimation methods which provide an accurate corrector to objective functions of interest in aerodynamic analysis, but, at significant expense. These methods require grids at least twice as fine as the baseline mesh in a 2D simulation and at least 8 times as fine in 3D. They also rely on a single field for anisotropy, which may not adequately capture the physics of complex multiphysics flows. This work focuses on the use of an a priori error estimate, to inexpensively compute the adaptive metric on the current mesh. In particular, the authors will apply this procedure to hypersonic flows in thermochemical nonequilibrium to demonstrate its ability to adequately adapt meshes for multiphysics problems. The framework will utilize SU2 to compute flow and adjoint solutions as well as the adaptive metric, and AMG to perform adaptation.