Abstract
In recent years, high-tensile steel sheets (hereafter HSS) have been widely used in car products in order to satisfy high collision safety and low fuel consumption. Owing to the high yield stress, it is still difficult to predict the final shapes of HSS by using commercial finite element codes. The improvement of prediction for wrinkling, fractures and spring back have been strongly demanded. In order to satisfy the demand, a new high order yield function (we call Yoshida 2012 yield function) was introduced into the ommercial finite element code Marc 2013 in the present research. The evaluation of this yield function was conducted. From the comparisons of experiment and its calculations, it is found that the accuracy of this yield function is quite well and spring back calculation by using this function also moderate.
