Wrinkling predictions in the deep-drawing process of anisotropic metal sheets

摘要

The onset of wrinkling in sheet metals is first analysed as an elastic-plastic bifurcation for thin and shallow shells with compound curvatures. Plastic yielding is described using a criterion recently proposed for transversely anisotropic materials. A local analysis is developed, which allows us to define wrinkling limit curves depending on material properties and local geometry. Finite element (FE) simulations of the conical cup test are also performed using the Abaqus/Explicit code. The FE results relating to the initiation of wrinkling in the wall are compared with the predictions of the bifurcation model. In addition to the intrinsic effect of anisotropy on wrinkling tendencies, it is shown that the attainment of critical wrinkling conditions is significantly affected by the influence of anisotropy on the stress state and sheet curvature developed in the wall prior to bifurcation.