Development of a mechanical joining process for automotive body-in-white production

Abstract

The current lightweight design is realized by the multi-material mix in body-in-white production of automotive industry. In car bodies, the proportion of high-strength steels and aluminum alloys increases. Therefore, it is necessary to join these materials. Mechanical joining processes are suitable for a multi-material mix. But in combination with high-strength steels, only processes with additional elements, like rivets, are useful. The development of a new clinching technology shows a solution for an economical method for joining these different materials. An innovative single-stage process without any additional joining elements is created to extend the current limits of mechanical joining technologies. This makes it possible to join aluminium alloys and high-strength steel by punching and clinching in one step. Using the special material behavior of the parts to be joined is most important for this mechanical joining process. A clinching sequence, a scheme and a gradual analysis support the understanding of this joining method. Some examples of connected material combinations complete this description. Further steps to improve this joining process are shown. Especially the finite element analysis will provide more process details for improving this innovative joining technology.