EnginSoft - Conference Abstracts

EnginSoft International Conference 2009
CAE Technologies for Industry

Digimat Material eXpert – From the Material Lab to the Efficient and Optimal Design of Reinforced Plastic Parts

Depouhon A. - e-Xstream Engineering (Luxembourg)
Lepage S. - e-Xstream Engineering (Luxembourg)
Assaker R. - e-Xstream Engineering (Luxembourg)

Abstract

Fast and cost efficient design of higher quality, lighter and more energy efficient vehicles is one of the key success factors for today’s automotive industry. Predictive CAE and the use of composites materials, offering good weight to mechanical performance ratio, are two ingredients that will help the industry moving forward profitably. The nonlinear Finite Element Analysis (FEA) of automotive parts using homogeneous isotropic materials like steel is challenging but has become today a standard step in any modern design process. The FEA of metallic parts is very well performed using one of the leading FEA packages such as ANSYS and LS-DYNA. The nonlinear FEA of injection molded parts using fiber-reinforced plastics is much more challenging and still suffers from a lack of modeling tools, simulation procedures and the material data that are needed to deal with the local, processdependent, anisotropic, nonlinear and strain rate dependent behavior or the reinforced plastics. In this paper, we will introduce the nonlinear micromechanical modeling technology that can be used to predict the nonlinear behavior and failure of a multi-phase materials, based on their underlying microstructure (e.g. fiber content, fiber orientation, fiber length, …). The multi-scale material modeling process, used to model the reinforced plastic part, will then be presented. This process uses structural ANSYS or LS-DYNA at the part level coupled to nonlinear micromechanically-based material models, taking into account the fiber orientation predicted by Moldflow. Nonlinear multi-scale modeling technology, including mean-field homogenization methods (e.g. Mori-Tanaka), advanced material models (e.g. Elasto-Viscoplastic and Micro Failure), realistic microstructures (e.g. complex fiber orientation and fiber length distribution) and strong coupling to Moldflow, ANSYS and LS-DYNA software is implemented in the DIGIMAT software platform. The effective and efficient use of this platform for the industrial design of plastic parts requires nonlinear material properties (e.g. stress-strain curves) of the composites and/or phase (e.g. polymer matrix). The storage, transfer and the Reverse Engineering (RE) of some missing material data is handled in the Material eXpert system that has just been added to the DIGIMAT platform. The industrial use of nonlinear multi-scale modeling technology will be illustrated using an automotive plastic part subject to quasi-static (ANSYS) and impact (LS-DYNA) loading conditions. This application will show the entire multi-scale modeling process with a special attention to the preparation of the micromechanical material model from available experimental data.


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