This presentation was made at CAASE18, The Conference on Advancing Analysis & Simulation in Engineering. CAASE18 brought together the leading visionaries, developers, and practitioners of CAE-related technologies in an open forum, to share experiences, discuss relevant trends, discover common themes, and explore future issues.

Resource Abstract

This presentation will cover a development of a multi-scale material model for a 3rd Generation Advanced High Strength Steel (3GAHSS) based on integrated computational materials engineering principles (ICME Model). Following a brief overview of the ICME project, a material model development will be described. The model combines micro-scale material properties defined by the crystal plasticity theory with the macro-scale mechanical properties, such as flow curves under different loading paths. For an initial microstructure the flow curves of each of the constituent phases (ferrite, austenite, martensite) are computed based on the crystal plasticity theory and the crystal orientation distribution function. Phase properties are then used as an input to a state variable model that computes macro-scale flow curves while accounting for hardening caused by austenite transformation into martensite under different straining paths. The ICME model calibration is implemented in the LS-OPT analysis tool as a component of an optimization process. The final result of the ICME Model calibration is a user-defined material subroutine, implemented in LS-DYNA finite element analysis software. A design optimization of a vehicle structure using the multi-scale ICME Model will also be presented. Design optimization of a vehicle body side structure was conducted using the new grades of 3GAHSS with the objective to minimize mass while maintaining key structural performance at par with the body structure used as a baseline. Shape optimization of main structural members was performed together with the optimization of part thickness and material selection. Optimization results show a 30% mass reduction potential of a mid-size sedan body side structure with the use of 3GAHSS. Design optimization steps, as well as the challenges in application of ICME models in vehicle design integration and optimization will be addressed. The presentation will conclude with integration steps that are needed to enable vehicle performance metrics driven material development in terms of chemical composition and phase characteristics.