Studies on the Processes Design of Multi-Step Sheet Metal Forming

It is well known that the design of multi-step sheet metal forming process is rather difficult. Even small errors may cause significant quality problem. In recent years, finite element analysis (FEA) has being considered as an essential tool for the design. Using a commercial FEA package, DYNAFORM, this paper studies the design of multi-step sheet metal forming processes, especially on how the design of the intermediate steps affect the forming quality. For a rectangle box with a rectangle protrusion inside, several different forming schemes are investigated by means of FEA. The study reveals that the strain path plays an important role. Accordingly, a couple of design rules are suggested.