Enhancement of Edge Crack Predictability for Automotive High-Strength Thick Steel Sheets Considering the Pressure Effect

This paper deals with the prediction accuracy of edge crack of automotive high-strength thick steel sheets according to the numerical simulation method. The mechanical tests under tension, tension/compression and loading-unloading conditions were performed to evaluate anisotropy, hardening behaviour and elastic modulus change, respectively. Edge stretchability was evaluated by the HER(hole expansion ratio) test according to the hole processing method. Based on the measured data, three simulation methods were constructed with respect to the material model and the element type. The half dome test was selected for verifying edge crack predictability according to the simulation method. The simulation results show that the pressure effect along the thickness direction has significant effect on prediction accuracy of edge crack for high-strength thick steel sheets used for automotive chassis parts.