Evaluation of Critical Stress Intensity Factor for Different RSW Joints

The aim of this paper is to evaluate the critical stress intensity factor (fracture toughness) for a range of Resistance Spot Welding (RSW) joints. The geometry of resistance spot welding joints under investigation comprises lap joints and coach peel joints of 316L stainless steel. The critical stress intensity factor of RSW lap joints and coach peel joints is calculated based on the experimental results of the shearing tensile tests and peel tensile tests, respectively. The welding parameters under investigation are the welding current, welding time, and electrode force. This study employs a fracture mechanics-based approach, to investigate the influence of RSW welding parameters on the critical stress intensity factor. The results demonstrate that the critical stress intensity factor exhibits a relatively decreasing trend with an increase in the welding current, from 8 kA to 16 kA. Moreover, an increase in the nugget diameter is particularly influenced by an increase in the welding current.