EXTENSION OF THE BACKWARD TRACING SCHEME OF THE RIGID-PLASTIC FEM IN 3-DIMENSIONAL DEFORMATION

Preform design is one of the critical fields in metal forming. The fin ite element method (FEM) has been effective in designing preforms and process sequence, for which the backward tracing scheme of the rigid-p lastic FEM has been explored. In this work a program using the backwar d tracing scheme of the rigid-plastic FEMs developed for three-dimensi onal plastic deformation, which is an extension of the scheme from two -dimensional cases. The calculation of friction between workpiece and die, and handling of boundary conditions during backward tracing requi re sophisticated treatment. The developed program is applied to upsett ing of a rectangular block and to side pressing of a cylindrical workp iece. The results of tile two applications show feasibility of the pro gram on three-dimensional plastic deformation.