Stretch-bending crack simulation for advanced high-strength thick steel sheets considering the contact pressure effect

Abstract This paper deals with simulation methods for predicting exact crack position of advanced high-strength thick steel sheets under the stretch-bending condition. The material properties related to anisotropy and hardening behavior were investigated from the tensile test, the loading-unloading and the tension/compression test. The stretch-bending test incorporating DIC ARAMIS system was performed for various punch radii in order to investigate the crack position and the fracture strain. Three simulation methods were established according to the material model and the element type for finding key points for the stretch-bending crack prediction. Simulation results show that the contact pressure effect should be considered for predicting the accurate stretch-bending crack phenomenon. A proposed simulation method can be effectively utilized to the sheet metal forming process design of automotive high-strength chassis parts.