An investigation on springback/negative springback phenomena using finite element method and experimental approach

Abstract

In sheet metal forming processes, one of the main problems is the occurrence of springback/negative springback which can be influenced by various factors. A number of research scientists have conducted valuable investigation on springback phenomenon. However, the negative springback problem has rarely been investigated. In this study, the effect of geometric and non-geometric parameters such as sheet thickness, sheet anisotropy, and punch tip radius on the springback/negative springback phenomena was investigated using the finite element method (FEM) and experiment in V-die bending of CK67 anisotropic steel sheet. The two approaches illustrated the occurrence of negative springback in smaller punch tip radii of the punch. Also, variations of springback and negative springback angle versus punch tip radius were shown. It was observed that increasing the sheet thickness results in a decrease in the springback and negative springback angle. Furthermore, it was shown that by increasing the bending orientation to the rolling direction, the amount of yield stress, springback, and negative springback angle increased.