Integrated material modelling on the crashworthiness for automotive high-strength steel sheets

Abstract

The aim of this study is to investigate the impact of microstructure features on the crashworthiness for automotive high-strength steel sheets by using multiscale modelling approach on different length scales, which provides a toolkit for the further microstructure design to meet the desired improvement of component performance. An extensive experimental program is designed involving various sample geometries that cover a wide range of stress states and tests are performed under quasi-static and high strain rate conditions and up to 2500 s-1 for an automotive dual-phase steel sheet (DP1000). The modified Bai-Wierzbicki (MBW) damage model is extended to a non-local formulation to cope with the simulations for lab and component levels. For the linking between the microstructure and mechanical properties, the representative microstructure model which considers the distributions of grain size, grain shape, crystallographic orientation and misorientation etc., is employed. The bridging between the models at different levels are powered by the virtual experiments and the entire approach is validated by lab-scale experiments and the crash box tests. © 2017 Chinese Society of Theoretical and Applied Mechanics. All Rights Reserved.