Wrinkling of anisotropic sheet metals under deep drawing

Abstract
Stamping industries tend to use thin, high-strength metallic sheets, in an effort to lighten the weight of structures. As a result wrinkles frequently develop during stamping processes. In practice wrinkling can occur on the flange or on the wall of the blank. The aim of this paper is to forecast the occurrence of wrinkling on the wall of the blank. Two methods have been developed to capture the onset of wrinkling. The first method is based on a bifurcation analysis for a doubly curved sheet. Wrinkling limit curves are determined by this analytical study. The second method uses finite element (FE) simulations. Two deep drawing tests are simulated using the dynamic explicit FE code ABAQUS/Explicit. FE results combined with analytical predictions allow us to outline the influence of normal anisotropy on the onset of wrinkling. The analytical and the numerical predictions are in fair agreement with experiments from the literature.