OPTIMIZATION DESIGN OF VARIABLE BLANKHOLDER FORCE IN U-SHAPED PART FORMING TO ELIMINATE SPRINGBACK ERROR

摘要

The central concern in forming U-shaped parts is springback that affects the geometries of the part. Variable blankholder force can reduce springback. But to date there has been no system for determining blankholder force trajectory. In this paper an optimization design method of variable blankholder force is actualized by combining an improved hybrid optimization algorithm with FEM software. The method was validated numerically using FEM to simulate the benchmark of 2-D draw bending problem in NUMISHEET'93. Cracking was eliminated and dimensional accuracy improved to yield a higher forming quality than was possible with constant blankholder force and an experiential method.