Finite Element Simulation of Resistance Spot Welding Process

The nugget growth and the residual stress evolution during a resistance spot welding process are calculated using the finite element simulation, based on the incrementally coupled electrical-thermal-mechanical modeling techniques. In the present simulations, the changes among liquid/solid phase and the evolution of microstructures are considered. In addition, differences among the stress-strain relations for the different microstructures are taken into account, because they seem to affect the residual stress field strongly. Case studies on welding of double sheet lap joints are demonstrated, and the simulated results showed good agreement with the experimental measurements.