Fatigue lifetime prediction model for spot welded structures

Structural components in the car industry are often assembled by resistance welding. Submitted in service to multiaxial loading, those components have to meet fatigue resistance requirements (amongst others). The aim of the proposed model is to predict the lifetime of spot welded structural components. It also allows to optimize the position and number of spot welds and simplifies the precise choice of an adapted material grade. The fatigue crack initiation resistance of a spot weld is supposed to be represented by a combination of normal force and total shear force. The model has been validated with experimental results obtained on structure- type specimens.