Blank Design and Strain Estimates for Sheet Metal Forming Processes by a Finite Element Inverse Approach with Initial Guess of Linear Deformation

Abstract

A new finite element approach is introduced for direct prediction of blank shapes and strain distributions from desired final shapes in sheet metal forming. The approach deals with the geometric compatibility of finite elements, plastic deformation theory, minimization of plastic work with constraints and a proper initial guess. The algorithm developed is applied to cylindrical cup drawing, square cup drawing and oil pan drawing in order to confirm its validity by demonstrating reasonably accurate numerical results for each problem. Rapid calculation with this algorithm enables easy determination of various process variables for design of a sheet metal forming process.