A crystal plasticity finite element analysis on the effect of prestrain on springback

Abstract

An incremental elasto-visco-plastic self-consistent polycrystal model was directly interfaced with a finite element (FE) code and applied to simulations of a mild steel sample subjected to 3-point-bending (3 PB). Emphasis is put in applying this strategy, for the first time, to predict springback responses after various amounts of prestrains. The crystallographic orientation distribution obtained from an EBSD scan was used to assign the initial polycrystalline aggregate for each FE integration point. The RGVB dislocation-density-based hardening model was adopted as the constitutive law, and the parameters were characterized by fitting uniaxial tension and tension-compression flow stress curves. The numerical reliability of the FE simulation results was evaluated via a systematic numerical study in terms of the mesh size, the numbers of grains sampled per each FE integration point and the cross-section points. The model successfully predicts the effect of prestrain on the springback, thus implying that the current modeling approach can be directly applied to industrial forming and springback predictions.