Springback simulation in sheet metal forming using material formulation based on combined isotropic-kinematic hardening with elasto-plastic anisotropy

The ambition to reduce development time and consts in the metal forming industr y has led to a wide application of finite element (FE) codes. Commercial FE-programs for sheet forming simulation give good results in terms of formability, strain distribution, wrinkling etc. Springback, however, remains a phenomenon often reported as being difficult to simulate. There are certain aspects which make springback especially critical for sheet metal forming. So, even small angular springback in deep-drawn structures may cause large spatial deformations and distortions of the whole part. This behaviour is expecially dramatic in case of open contours having small bending stiffness in one direction. The application of new materials, including high strength steel, aluminium and magnesium alloys, for light weight structures in the automotive industry is often impeded by the insufficient predictability of the springback effect.