FEM Simulation of Springback in Aluminium Sheet Metal Bending Process

摘要

Springback during unloading affects the dimensional accuracy of sheet metal parts. The purpose of this study is study the factors influencing springback. A finite element model based U-bending benchmark of NUMISHEET'93 has been used to predict springback with contact evolution between the sheet and dies. Sheet unloading is simulated by the tools' reverse motion. The solutions are validated with experimental data of NUMISHEET'93. The effects of the form of variable blank holding force (VBHF) on springback results are investigated. It is found that VBHF form has great effect on springback. When the latter force is larger than the former force of VBHF, springback is reduced effectively. Using the stepped and trapezoid with a right angle binder force trajectory is better.