2010 年 51 巻 597 号 p. 963-968
Hemming is a forming method of connecting an outer panel to an inner panel by bending a hem flange at the edge of the outer panel. Depending on the complex shape of the hem flange bending line, springback occurs because the stress in panels is released after die opening. To estimate deformation by springback, a hemming simulation method using explicit and implicit finite element simulations for complex panel shapes has been developed. Because of the complexity of elastic contact conditions at hemmed portions between the inner and outer panels, it is difficult to obtain converged solutions of springback using implicit finite element simulation. In order to solve this problem, we have developed a new method that entails connecting the inner panel edge to the outer panel to avoid contact analysis. It enables the appropriate simulation of the hemming process within a short computing time based on the verification of hood parts. The proposed method can be used to investigate the strength of stiffness, the dimensions of the inner/outer panels and the hem flange shape (length/angle) to obtain geometrically accurate hemmed parts by predicting the amount of springback after the hemming process.