| Abstract Scope |
The use of simulation tools to understand thermal cycles in welds has been an ongoing fascination of researchers since Daniel Rosenthal proposed the first analytical solutions for arc-based processes in 1941. Over the decades, modeling activities have progressed from enhancements to the earlier analytical efforts to through the application of various numerical tools to the multi-physics approaches commonly employed today. Modeling resistance spot welding has followed a similar path. Early efforts by researchers in the 1960's largely employed various analytical constructs, but by the 1980's and beyond efforts had shifted to numerical techniques. All models, of course are simply representations of reality based on best case assumptions and the accuracy of the analysis tools employed. The result has been an ongoing series of models largely trading accuracy for computation time. For industrial applications however the time required to create a solution must be weighed against the inherent value of the added accuracy. Some applications drive for high resolution solutions where root causes to problems require more extensive definition of local changes to microstructure, geometry, etc. However, for a broad range of applications lower resolution solutions are sufficient to provide insights into process behavior and provide first order assessments of joint quality. These then become tools that can offer economical solutions for a vast array of resistance welding related challenges. This presentation addresses the evolution of analytical concepts for addressing modeling of resistance spot welding. Evolving models are described in terms of the constructs employed and assumptions made. More recently, the use of improved calculation techniques allowed cascading of such analytical models allowing further improvements in the quality of predictions made. Examples will be provided in this presentation on how such models provide insights not just with regard to temperature excursions, but also tempering response, and even electrode wear with repeated welding. |