Recent Advances on Modeling Plastic Deformation of Textured Metals with Applications to Metal Forming

Due to the ease in calibration from simple tests and the reliability of the parameter identification, generally von Mises isotropic criterion and Hill orthotropic criterion are used in industry. While more advanced 3-D yield criteria have been developed, generally such criteria are written in terms of eigenvalues of transformed stress tensors, and as such the anisotropy coefficients are not directly related to mechanical properties. Therefore, the quality of the F.E. simulations depends on the experience of the analyst in calibrating these parameters. Very recently, it was shown that all advanced non-quadratic yield criteria are in fact polynomials in terms of stress components (see [1]). Moreover, for the 3-D orthotropic criteria involving one linear transformation (e.g. Yld91), the anisotropy coefficients can be determined using analytical formulas, involving only four yield points or three Lankford coefficients, respectively (see [2, 3]). In this paper, the predictive capabilities of the orthotropic criteria of Hill [4], Yld91 [5], and Cazacu [6] calibrated using both analytical and numerical minimization procedures are discussed. Moreover, simulation results of deep drawing of steel alloy DC06 are presented. The influence of the choice of the criterion, the procedure used for identification (analytical vs. numerical), and the type/extent of the data used for identification are analyzed in detail.