Prediction and elimination of springback in straight flanging using computer aided design methods: Part 1. Experimental investigations

A computer aided design method for straight flanging using finite element method is presented. The predictions have been validated with some laboratory experiments, and this method was applied on a specific type of flanging in which the edge is coined at the end of the operation. The experiments included die corner radius, punch–die clearance, punch nose radius, pad force and material type as the main variables. Some selected cases from the experiments were simulated using two commercial finite element programs: DEFORM™ and ABAQUSTM, and the results were compared with the experiments and the sources of error were discussed. Next, flanging with coining was investigated as a method to eliminate springback and to improve part quality. This first paper in a two-part series presents the experimental investigations on the effect of process variables on springback in straight flanging process. The second paper covers the finite element analysis of flanging, and evaluates the influence of flanging with coining on pre-hemming and hemming processes.