Elasto-Plastic Finite Element Analysis with Directional Reduced Integration in Sheet Metal Forming

Abstract

Sheet metal forming process involves complicated stress state with large rigid body rotation and translation. The analysis of the process, therefore, is generally carried out by the finite element method with large deformation. The numerical procedure needs some remedy for the locking phenomenon particularly due to bending effect to obtain a good result. In this paper, an updated Lagrangian finite element formulation with directional reduced integration for hourglass control is developed and applied to the sheet metal forming process with the yeasty-plastic, work-hardening material. The numerical results are compared with the results obtained from axisymmetric hydrostatic bulging experiments. The result and comparison elucidate the improvement of numerical solutions and computing efficiency by removing the hourglass mode and the shear locking.