Due to the high stress concentration of spot welding joints

it is very easy to initiate fatigue cracks at the edge of the nugget

and the residual stress produced by spot welding will affect its propagation. To explore the influence of spot welding residual stress on fatigue crack propagation

a three-dimensional finite element simulation model of DP600 high strength steel spot welding joint was established. Based on the thermal-elastic-plastic theory

the residual stress field of spot welding was solved. On this basis

the local stress intensitv factor (SIF) solution of the kinked crack with and without residual stress was calculated. By analvzing the variation curve of the local stress intensity factor at the deepest point of the crack with the crack depth ratio under the two conditions

the influence of residual stress of spot welding on the propagation of kinked crack was studied. Based on the fracture mechanics theory

the improved two-parameter model is used to predict the fatigue life wit th and without residual stress. The results show that the residual stress of spot welding significantly increases the local stress intensity factor

and the influence of residual stress on it increases with the increase of crack depth ratio. Considering the residual stress

the overall crack propagation trend remains unchanged but the propagation rate increases significantly

and the fatigue life decreases from 35 616 times to 12 564 times.