Development and application of the material constitutive model in springback prediction of cold-bending

Abstract

The accuracy for cold-bending springback prediction is determined by the sensitivity and accuracy of the material constitutive model. Thus, the material constitutive model is developed and improved by many researchers, and the improved models are applied in the springback calculation with various materials in finite element simulation or theoretical analysis. To provide a reference for the researchers studying cold-bending springback problems, a review of the development and application of the material constitutive models is presented in this paper, which conducts from the elastic behavior, the anisotropy, and the work-hardening. It can be summarized as: (1) Springback prediction result is higher and more accurate when the variable elastic modulus and the nonlinear recovery are considered. (2) The isotropic hardening leads to an overestimation of the springback, which can be avoided by a hardening model describing the Bauschinger effect. (3) The hardening model has greater impact on springback than the yield criterion. (4) Good accuracy of the springback prediction can be achieved when the variable elastic modulus effect, the material anisotropy and the nonlinear hardening are considered together. It is also found the theory development and practical application of the material constitutive models are out of line, due to lacking further experiment, or that the stress loading–reloading history within a bending part may be not so complex as that “ratchetting behavior” discussed.