Experience of joining of high strength automotive sheet in the body shop

In addition to lightweight design, central topics in modern automotive engineering are the continuous optimization of active and passive safety, of corrosion protection and of the general properties in terms of usage and function of the overall vehicle. In order to achieve optimal functionality, economic efficiency and, eventually optimized vehicle weight, the process engineers and design engineers daily face new challenges. Important milestones to achieve these targets are the selective use of new and advanced materials and the provision of proven product,- joining-, testing- and repair processes. In particular the variety of materials expected in the future, once again poses new challenges to the joining and connection technology. Existing joining processes (e.g. resistance welding, shielded arc welding and brazing, laser welding, stud welding, adhesive bonding, self pierce rivet) must be further developed and be supplemented by new process variants. The design of joined components of vehicle structures so that they can achieve required service performance limits without an increase of vehicle weight or cost is of paramount importance to automotive manufacturers. Achieving this goal requires careful selection of, both, steel material and joining technique as well as detailed knowledge of the elastic and plastic behavior of the joined sections, particularly under cyclic loading. This also includes new procedures for the release of new materials and processes from the viewpoint of joining technology. Based on examples of new material and body concepts applied within the BMW Group a report on the results and experience gathered in the application of various joining processes is given. (AU)