Semi-Analytic Hybrid Method to Predict Springback in the 2D Draw Bend Test

Abstract

A simplified numerical procedure to predict springback in a 2D draw bend test was developed based on the hybrid method which superposes bending effects onto membrane solutions. In particular, the procedure was applied for springback analysis of a specially designed draw bend test with directly controllable restraining forces. As a semi-analytical method, the new approach was especially useful to analyze the effects of various process and material parameters on springback. The model can accommodate general anisotropic yield functions along with nonlinear isotropic-kinematic hardening under the plane strain condition. For sensitivity analysis, process effects such as the amount of bending curvature, normalized back force and friction, as well as material property effects such as hardening behavior including the Bauschinger effect and yield surface shapes were studied. Also, for validation purposes, the new procedure was applied for the springback analysis of the dual-phase high strength steel and results were compared with experiments.