Finite element simulation of creep-fatigue crack growth behavior for P91 steel at 625 °C considering creep-fatigue interaction

A creep-fatigue crack growth model considering creep-fatigue interactions based on continuum damage mechanics was proposed in this paper. Numerical analyses of creep-fatigue crack growth of P91 steel at 625 °C using compact specimens were conducted. The results agreed well with the experiment which indicated its good capability in predicting creep-fatigue crack growth behavior. The effects of initial crack depth, specimen dimension and hold time on crack growth behavior were investigated using the model. The results indicated that the increasing initial crack depth and specimen dimension promoted the crack growth rate, while the decreasing hold time accelerated the crack growth.