Incremental Sheet Forming - Process Simulation with LS-DYNA

Incremental CNC sheet forming (ISF) is a relatively new sheet metal forming process for small batch production and prototyping. In ISF, a blank is shaped by the CNC movements of a simple tool in combination with a simplied die. The standard forming strategies in ISF normally use some kind of die in order to increase the accuracy of the final part. Therefore in this paper the main focus is on a process variation that uses an incremental die to replace the die. By using this new process the tooling costs for the die will become minimal and the geometric accuracy is higher as without die. However, an empirical approach to tool path optimization for an increased accuracy will yield an enormous experimental effort. This motivates the use of process modeling techniques. This paper deals with finite element modeling of the "ISF process with an incremental die system" in LS-Dyna. In particular, the simulation setup and the tool path generation is explained in detail. We will also give a short summary of the state of the art in ISF and about the material modeling in LS-Dyna. The paper addresses mainly the industrial user who would like to perform ISF simulation without bothering about the difficulties of the simulation setup.