Spot weld fatigue life prediction – new criteria

International audienceThis paper presents new criteria for fatigue life prediction of spot weld. It starts with the presentation of the database used for this study. Then, a sensitivity analysis is performed to determine the influential variable on the lifetime of spot weld. Two criteria for spot weld life prediction, based respectively on mechanical damage and fracture mechanics, are developed through a nonlinear multiple regression method of optimization. These criteria considerably improve the correlation between numerical and test results. Finally, an application of this study is led on a fatigue test of a full body-in-white with about 4000 spot welds