Simple prediction method for the edge fracture of steel sheet during vehicle collision - Evaluation of fracture limit from the edge using small-sized test pieces

K. Watanabe, M. Tachibana (Kobe steel, Ltd.), K. Koyanagi, K. Motomura (Toyota Auto Body Co., Ltd.) At vehicle collisions, fractures occur from the edge of steel sheet. Existence of any fracture has an influence on the accuracy of vehicle crash simulations. In order to obtain a simple evaluation index of the fracture limit, fracture limits around the holes processed using several methods were measured. It was clarified that these fracture limits are represented by a combination of the elongation and the hole expansion ratio of steel sheet.