Earing prediction in cup drawing based on non-associated flow rule

An anisotropic constitutive model based on Non-Associated Flow Rule (Non-AFR), which incorporates plane stress yield functions (Hill's quadratic function [1] and Yld2000-2d by Barlat et al. [2]), was implemented to finite element codes (ABAQUS, LS-DYNA 3D) by using User Material options. By using Non-AFR, Yld2000-2d is capable of predicting more than four ears which is possible only with Yld2004 by Barlat et al. [3] when used with an Associated Flow Rule. A short review of the Non-Associated Flow Rule was provided. Simulation of the cup drawing process for a rigid container sheet alloy using mini-die geometry was performed to show the cup height profile (earing profile) obtained from Non-AFR. The simulation results were compared with experimental earing profile data and it was shown that the simulations using Yld2000-2d and the Non-AFR led to the excellent prediction of the earing profile