Springback Analysis and Optimization in Sheet Metal Forming

An accurate prediction of springback in sheet metal forming processes requires complex hardening material models. In this research, numerical analysis of the springback in U-bending was conducted using the well-known Yoshida model, available and known as the YU model in LS-DYNA. This model has seven main parameters which describe the behaviour of the material as it undergoes metal forming processes. Initially, mesh sensitivity studies were conducted to derive a suitable mesh that represents an appropriate compromise between accuracy and computer time. Secondly design of experiment (DoE) was employed to make 30 combinations of two design variables (die radius and clearance) uniformly through a design space. Parametric optimisation studies were also conducted to investigate the influence of these variables and to make recommendations to minimise the springback. The results show that the blank element mesh density has a significant effect on the springback prediction. Additionally the results demonstrate that certain geometrical parameters have a significant impact in controlling the springback but that optimised values can be identified to minimise the effect.