Interaction effects of residual stress and constraint on fatigue and creep–fatigue crack growth in GH4169 hole structure

This study uses numerical simulations to investigate the fatigue crack growth (FCG) and creep–fatigue crack growth (CFCG) behaviour of GH4169 specimens with holes under the interaction between residual stress and constraint at 650°C. The results show that the residual stress introduced by the preloading method is compressive, and this residual stress suppresses both FCG and CFCG. Under the same preload condition, the crack growth rate increases gradually with increasing constraint. In the absence of residual stress, the CFCG rate is significantly higher than that under pure fatigue loading. For the CFCG behaviour with a preload of 200 MPa, the crack propagation in the early stage is strongly influenced by residual stress, and the interaction between constraint and residual stress leads to complex crack growth behaviour. As crack propagation proceeds, the influence of constraint gradually becomes more dominant.