Importance of appropriate modeling of the Bauschinger effect in springback analysis

摘要

FE analysis of springback after hat-shaped draw-bending for various die radii were conducted using the following four types of material models a) the isotropic hardening model (IH model); b) the linear kinematic hardening model (LK model); c) the IH + Armstrong-Frederick-type nonlinear kinematic hardening model (IH +NLK(AF)model); and d) the present authors' original model which is characterized by the accurate description of the transient Bauschinger effect (Yoshida-Uemori model). Experiments were also performed on high-strength steel sheets to enable comparison of the analytical predictions with the experimental results. It was found in the present work that proper modeling of the Bauschinger effect is of vital importance as well as the prestrain dependency of Young's modulus for accurate prediction of springback. Among these material models, the Yoshida-Uemori model gave the most accurate predictions of springback.