Process forces during remote laser beam welding and resistance spot welding - A comparative study

Welding of sheet metal in the automotive industry involves inflexible and expensive joining fixtures to properly position and fasten the parts that are to be joined. Feature-based fixturing is an approach to reduce fixtures in the assembly process. The approach relies on part-inherent fastening features that realize the functions of positioning and fastening. The proper design of these fastening features requires knowledge of forces that result from the joining process and thus need to be compensated. This paper describes the investigation of process forces during remote laser beam welding and during resistance spot welding. This is achieved by using a thermo-mechanical simulation model and experimental studies. The comparison shows significant differences in process forces that result from the two different processes. Finally, the results allow for the design of fastening features to reduce joining fixtures in the automotive body shop.