Prediction of earing in TWIP steel sheets based on coupled twinning crystal plasticity model

Abstract

By combining the nonlinear finite element analysis techniques and crystal plasticity theory, the macroscopic mechanical behaviour of crystalline material, the texture evolution and earing type characteristics are simulated accurately. In this work, a crystal plasticity model exhibiting deformation twinning is introduced based on the crystal plasticity theory and saturation-type hardening laws for FCC metal Fe-22Mn-0.6C twinning-induced plasticity (TWIP) steel. Based on the crystal plasticity finite element (CPFE) model and parameters which have been determined for TWIP steel, a simplified finite element model for deep drawing process is promoted by using crystal plasticity constitutive model. The earing characteristics in typical deep drawing process are well simulated. Further, the earing profile and drawing forces are calculated and compared with the experimental results from the references. Meanwhile, the impacts of drawing coefficient and initial texture on the earing characteristics are investigated for controlling the earing. According to the result of the simulation, earing rate manifests a downward trend with the drawing coefficient increasing, and two different earing types of 6-0°/60° and 4-0°/90° occur with the brass, cube and gauss type of initial texture.