2019 Volume 60 Issue 699 Pages 115-120
The hole expansion behaviors of mild steel sheets were investigated by experiments and finite element simulations, using three anisotropic yield functions: Hill’48, Yld2000-2d, and Spline models. Spline yield function was expanded to allow the arbitrary segments given by experimental stresses, strains, and strain increments, which are normal vector on the yield surfaces, in the biaxial stress state. Relationships between the yield function models and prediction accuracy were examined through the comparison of thickness distributions at a certain distance from the hole edge. In this work, it was found that accurate modeling of anisotropy affected the accurate prediction of thickness. It was concluded that Spline yield function, which was given the most numbers of experimental values, is the most accurate model in this research.
