Research on the process of stretch forming with reconfigurable tooling

A reconfigurable tooling system has been developed for sheet stretch forming. The working surface of the tool consists of the ends of numerous pins with hemispherical tips. With different position of the pins, the working surface of the tool can be different also. Then different parts can be manufactured by this tooling system. Because of the flexibility of the tool, production period and cost can be greatly reduced. During forming process, an interpolating polymer layer is placed between the tool and the sheet metal in order to suppress dimpling of the workpiece. In this paper, effects of the interpolating polymer layer and the springback of the workpiece on the final shape of the workpiece were analyzed by the finite element method. And then the working surface of the tool was modified to eliminate the effect. Several workpiece were fabricated in experiments, whose surface quality and final shape were perfect.