Prediction of plastic flow localization with shell element in thick AHSS sheets

Abstract

The aim of this study was to investigate the differences between shell and solid elements in the numerical simulation of a 2.85 thick DP780 sheet. It was observed the stress-strain response with shell elements was very different from the experiment after maximum load while, solid element showed a much better agreement. For shell elements, stress triaxiality had the tendency to abruptly converge at certain value while, with solid elements, the triaxiality was continuously increasing. To compensate for the limitation of shell element, the strain hardening curve was modified after maximum load. The method was validated with plane strain tension simulation.