Effect of residual stress on fatigue strength of resistance spot weldment

The estimation of fatigue strength of spot welded joints is crucial to the strength design of spot welded steel sheet structures. In the present paper, the effect of residual stresses on the fatigue life of resistance spot weldments was studied. Residual stress fields in the weldments were calculated using thermoelastic–plastic finite element analysis and the equivalent fatigue stress considering the residual stress effect was obtained. This was followed by fatigue life predictions, which included the effect of the residual stresses and the actual loading stresses. The calculation and experimental results showed good agreement. Therefore, the proposed calculation model can be considered to be sufficiently powerful for the prediction of fatigue life