Simulation of the effect of texture on limit strain in biaxially stretched steel sheet

Limit strains for biaxial stretching are predicted by the Marciniak and Kuczynski (M-K) method, suitably modified to take into account the textures present in sheet steels. The series expansion method is used for this purpose in the framework of the Taylor/Bishop and Hill theory. The effect on the limit strain of yield surface shape is allowed for by the use of an improvedP parameter. The experimental limit strains of an AKDQ steel are compared with the forming limit curves (FLCs) predicted on the assumption of two sets of slip systems with different critical resolved shear stresses (CRSSs). The limit strains in equibiaxial stretching with assumed groove orientations are also predicted for some idealized materials containing specific preferred orientations.