An analysis method for deep drawing process design

Abstract

An analysis method has been developed that predicts the strain distribution in deep drawn sheet parts. The method is based on plane stress characteristic theory, which neglects both normal and shear stresses acting across the thickness of the material, as well as variations through the thickness of in-plane stresses. Isotropic hardening and normal anisotropy have been introduced, and the von Mises yield condition and associated flow rule are employed. The theory is valid for regions in the sheet which are characterized by drawing as opposed to stretching deformation. The process model has been implemented as a computer program capable of modeling circular, square, and rectangular cups. The model considers only the deformation taking place in the flange region of the part, where most of the work of deformation occurs, but the resulting strain distribution is displayed on a geometric model of the entire part by making geometric assumptions about the movement of the material on the face of the punch. Computed strains are compared with experimental results and causes for discrepancies are discussed. © 1990.