Finite element computation of fatigue growth rates for mode I cracks subjected to welding residual stresses

This paper presents a finite element modeling procedure for predicting fatigue crack growth rate in butt welds subject to mode I loading condition. Sequentially coupled three-dimensional thermal–mechanical finite element model to simulate welding residual stress was first developed. The weld-induced residual stress effect on the fatigue crack growth rate was then modeled by calculating the stress intensity factor due to the residual stress field based on the superposition rule of the linear elastic fracture mechanics. The results demonstrated the significance of the residual stresses in assessment of the fatigue crack growth rate in the welds.