In making the die of automotive outer panels, the most difficult process is fixing surface deflection. To fabricate high-quality outer panels without modifying dies, it is important to develop an evaluation method and a numerical analysis method for the surface deflection of outer panels. In this study, we developed a new evaluation method that uses the maximum value of curvature, calculated using reflecting curves in the surface. This made the examiner evaluation conform to digital evaluation. The method shows better agreement with the examiner evaluation than the conventional method. We proposed a new analysis method of predicting surface deflection correctly. By the proposed method, plastic deformation is calculated in consideration of stress in the thickness direction, and restriking conditions are examined. We applied our methods to the fabrication of automotive outer panels and verified that they were useful and practical.
