Applications of a recently proposed anisotropic yield function to sheet forming

In this paper the predictive capabilities of a recently proposed yield criterion, CB2001, are assessed. Also, a numerical scheme for identifying the material coefficients is presented. It is shown that although convexity is not a default property of the criterion, it can be achieved numerically. Applications to two sheet forming operations are presented. Using the commercial FE code ABAQUS, simulations of the deep-drawing of a cylindrical cup and springback analysis for unconstrained bending are performed. Two aluminum alloys were considered and modelled with Hill'48 (ABAQUS) and CB2001 (UMAT). The results are also compared with another popular criterion, Yld'96. We conclude that for sheet forming operations were large plastic deformations are involved, accurate fit of the initial plastic anisotropy is a basic condition for successful FE simulations. © 2007 Springer-Verlag Berlin Heidelberg.