About the mechanical data required to describe the anisotropy of thin sheets to correctly predict the earing of deep-drawn cups

The nonuniform height profiles of deep-drawn cylindrical cups is caused by the plastic anisotropy of the blank sheet. Which locations on the yield surface determine uniquely the earing profile is still an unsolved problem. Present (phenomenological) theories take into consideration only the directional properties of the sheet (r-value and yield stress). We show here that these directional properties are not enough and that for a unique characterization of the earing profile, information about the pure shear yielding point must also be considered.