PREFORM DESIGN IN METAL-FORMING .4. PREFORM DESIGN IN PLANE-STRAIN ROLLING BY THE FINITE-ELEMENT METHOD

The problem of design of preform end shapes for eliminating crop loss in plane-strain rolling was investigated by the use of the finite-element method. For non-workhardening materials, the finite-element simulation of rolling of flat-ended plates shows the formation of defective end shapes. The finite-element simulation was further performed for rolling of a plate with approximate preform end shape in order to examine the approximate solutions. The backward tracing scheme by the finite-element method was applied to non-workhardening materials and more accurate preform end contours were obtained. Further, the effect of workhardening on preform shapes was investigated by using the backward tracing scheme. The results revealed that the effect of workhardening on the front end contour is appreciable, reflecing more complex deformation characteristics on the contour design.