Evaluation of Anisotropic Yield Function for Hole Expansion Test of DP and BH Steel Sheets

Abstract

Hole expansion (HE) test and simulation have been used to study stretch-flangeability and prevent edge cracking in sheet metal forming. Finite element analysis has been frequently used for simulation of formability test, and constitutive models was characterized as significantly influence the prediction. In this study, HE test for BH and DP steel sheet was simulated using ABAQUS software. The influence of friction condition, hardening curve and yield function such as von Mises, Hill1948, Yld2000-2d and Yld2004-18p were considered. In terms of punch force-displacement, the result was greatly influenced by friction condition, and the choice of hardening curve. For thickness strain distribution, the yield model give significant improvement in the prediction, especially in circumferential direction. It was found that Yld2000-2d and Yld2004-18p can increase the accuracy of the model. These thickness strain distribution assumed to predict the location of first crack in HE test, which is satisfactory for BH340 material.