PLASTIC ANISOTROPY IN FEM ANALYSIS USING DEGENERATED SOLID ELEMENT

Hill's quadratic, anisotropic yield criterion is implemented to the sh eet metal forming simulation FEM code ITAS-3D. Several problems arouse when a constitutive equation with anisotropic yield criterion and rel ated numerical procedures have to be formulated for shell like structu res. Strategy to deal with large rotations, anisotropy updating topics and stress updating procedure for degenerated solid element used in I TAS-3D code are presented in our paper. Finally, results of numerical simulation for an anisotropic steel sheet deformed in cylindrical deep drawing process are verified by experiment.