Investigation on the influence of damage to springback of U-shape HSLA steel plates

摘要

Springback prediction for a metal sheet during the forming process has always been a practical problem. In this paper, based on the mixed plastic hardening rule, which comprehensively describes the Bauschinger effect, transient behavior and permanent softening, a mechanical model considering the variable elastic modulus effect, nonlinear elastic recovery, initial anisotropy yielding criterion and damage evolution is established. Influence of damage on time-dependent springback for a U-shaped HSLA steel plate is investigated. The results obtained from numerical examples show that the hardening exponent, bending radius-thickness ratio, friction coefficient, blank holder force and damage have great influences on the springback of the U-shaped HSLA steel plate. Comparison example is conducted to verify the validity of the present model which can accurately predict the springback behavior of the U-shape HSLA steel plate. (C) 2017 Elsevier B.V. All rights reserved.