Surface stretch forming process based on collaborative control of sheet metal deformation and die contact state

Abstract

In this study, we propose a novel method of surface stretch forming, named the Surface Stretch Forming based on Collaborative Control of Sheet Metal Deformation and Die Contact State (SF-CCDC). By controlling the motion paths of the discrete clamps, the contact process with the die, and the deformation process of the sheet metal can be changed. The processes of conventional stretch forming (SF-C) and SF-CCDC were numerically simulated. The results show that in SF-CCDC, the shearing effect of the die edge on the sheet metal can be reduced through the collaborative control of sheet metal deformation and contact with the die. Compared to SF-C, the maximum thinning rate is reduced by 50%, and the risk of stretch cracking is lower in SF-CCDC. Furthermore, both the center and edge areas of the sheet make contact with the die simultaneously, ensuring adequate deformation constraints and preventing wrinkling defects. Experiments were conducted to demonstrate the reliability and adaptability of the SF-CCDC method for forming double-curved surfaces.