Identification of Kinematic Hardening Material Parameters for Martensitic Steel Sheets

The identification of the material models which are used in the finite element analysis for the forming operation and springback are very important in terms of accurate predictions. The aim of this paper is to characterize both the anisotropy and the hardening of the ultra-high strength steel such as martensitic steel (MS steel) in order to identify material parameters of constitutive equation, which able to reproduce the mechanical behavior. Uniaxial tensile tests were carried out for characterizing the anisotropic plastic behavior of the MS steel. Cyclic tests under tension-compression load were also carried out for characterizing the Bauschinger effect during reverse deformation. Yoshida-Uemori hardening model associated with orthotropic yield criterion Hill’s 1948 is used to represent the in-plane mechanical behavior of the martensitic steel. The resented results show a very good agreement between model predictions and experiments: flow stresses during loading and reverse loading are well reproduced.