FE-analysis of Channel Width Effects on Spring-back Characteristics in the U-bending Process

In this study, the effects of channel width on spring-back characteristics in the U-bending process were investigated using the finite element method (FEM) and laboratory experiments. Based on the stress distribution analysis, it was found that there were no changes to the bending and reversed bending stresses in the workpiece, when a pressure pad was used. In contrast, without a pressure pad, the channel width directly affected the bending and reversed bending stresses, which resulted in changes to the spring-back characteristics. These results confirmed that the effect of channel width on the spring-back characteristics could be neglected in the case of U-bending with a pressure pad but that it should be strictly considered in the case of U-bending without a pressure pad. The FEM simulation results showed good agreement with the experimental results in terms of both the bend angles and bending forces.