A User-Friendly Anisotropic Yield Function for Modeling Anisotropy of BCC and FCC Sheet Metals

A significant predicament of advanced yield criteria used in industrial environments is that its excellent performance is obtained at the expense of simplicity and experiment cost. This work develops a user-friendly anisotropic yield function to capture plastic anisotropy of BCC and FCC sheet metals. The proposed yield function balances the experiment cost in the parameter calibration procedure and predictability by coupling three groups of six-parameter linear transformation tensors into the Yld2011-27p criterion. The proposed function is applied to predict the anisotropic behavior of QP980 steel to verify its predictability. The function is also implemented into the ABAQUS/Standard to describe the earing profile of AA2090-T3 after cylindrical cup deep drawing to evaluate its effectiveness and calculation efficiency compared with the Yld2011-27p, Yld2004-18p, CPB06ex2, and reduced Yld2004 criteria. The results show that the simulation efficiency of the proposed yield function improved by 7.55% (save 2.13 h) compared with Yld2011-27p. In addition, compared with the Yld2011-27p criterion, the experimental cost in the parameter identification of the developed yield function for material with moderate and strong anisotropy is reduced by 50 and 25%, respectively. The suggested yield function is also applied to depict the anisotropic hardening behavior of AA7075-T6 in flow stress and capture the evolution of the r-value during plastic deformation. The comparison shows that the proposed model can illustrate the anisotropic yield behavior of the AA7075-T6 under different levels of equivalent plastic strain. In addition, the proposed model also well balanced the predictability and calibration cost. Accordingly, it is recommended to use the proposed model in high-fidelity numerical simulation of the sheet metal forming process and provide reliable results to optimize product design.