Predicting springback in sheet metal forming: an explicit to implicit sequential solution procedure

The springback properties of sheet metals make the design of forming dies extremely difficult. In this work a coupled explicit to implicit finite element procedure is outlined for predicting springback deformations in sheet metal forming processes. The explicit method is initially utilized to analyze the contact based forming operation of a production stamping process. Then, an implicit solution is performed to simulate the springback that develops in a blank after the forming pressure has been removed. Using this simultaneous solution technique on an actual automotive component, numerically predicted springback deformations are found to be within 1% of production values. The results of the numerical investigation indicate that the coupled finite element procedure described herein can be utilized to significantly reduce the number of die prototype designs that are currently required in sheet metal stamping operations, (C) 1999 Elsevier Science B.V. All rights reserved.