Experimental and numerical analysis of the influence of burst pressure distribution on rapid free sheet forming by vaporizing foil actuators

Abstract

Vaporizing Foil Actuators (VFA) can be employed as an innovative, extremely fast sheet metal forming method. An ultimate goal in forming technologies is generally to be flexible and rely on as few part-specific tools as possible. Therefore, various realizable VFA pressure distributions were investigated with a focus on the free forming result. Fundamental experiments including laser-based dynamic velocity measurements were conducted to discuss some key forming characteristics of the process. To compare more complex pressure distributions in a well-defined way, a numerical model was built. The strain rate dependency of the blank material was identified experimentally and incorporated in the model. It is shown that there are some VFA free forming capabilities in terms of creating certain part shapes, but only to a limited degree because relevant inertial forces can be present in regions where displacements would actually be either undesirable or wanted. Potential solutions to this are given at the end.