Numerical simulation of resistance upset welding in rod to tube configuration with contact resistance determination

A 2-D axisymmetric finite element model of upset resistance welding on tube to rod configuration is developed. It is based on an electrical-thermal-mechanical analysis and developed on commercial software MARC for nuclear fuel pin cladding welding application. It allows to assess local temperature and strain fields during welding. A parameter influence study reveals, among others, the importance of contact resistances between samples and electrodes. Some contact resistance models are proposed and a specific calibration method of those models, which implies experimental tests and numerical simulations, is developed. This calibration method allows to obtain a good agreement between the welding simulation and the relevant instrumented experiment for two different studied geometries.