A Finite Element Method for Calculating Binder Wrap Surface and Its Applications

This paper describes a robust and user-friendly finite element analysis program, WRAPFORM, and its applications in sheet metal formability analysis for autobody panels. In a sheet metal forming die, a blank undergoes two distinct deformation processes: the forming of a binder wrap and the forming of the part. WRAPFORM is used to analyze binder wrap forming by calculating the surface shape of the formed binder wrap. It was developed using a "black box" approach. The mechanics of the problem, solution procedure and finite element methodology needed in the calculation model were made transparent to the user. A designer with little computer experience can use the program to obtain the binder wrap surface in one computer run. Applications of WRAPFORM have yielded useful results. In one application, the designers' intent was verified. In another, the calculated binder wrap surface shape was used in guiding the modification of the layout of a sheet metal forming die