Evaluation of constraint effects on creep crack growth by experimental investigation and numerical simulation

Effects of constraint induced by crack depth on creep crack behavior of P92 steel was investigated by experimental investigation and numerical simulation. Creep crack growth tests were carried out on compact tension specimens with different crack depths. It revealed that the high constraint affected creep crack initiation time and steady creep crack growth rate. Then, the crack-opening stress distribution at crack tip during creep crack growth process was obtained by finite element method (FEM) analysis. The corresponding variation of constraint parameter Q was also obtained. Finally, a C*–Q approach was employed to characterize the creep crack growth rate.

► Effect of constraint induced by crack depth on creep crack growth is studied.
► High constraint induced by crack depth can reduce creep initiation time.
► High constraint induced by crack depth can reduce steady creep crack growth rate.
► Variation of constraint parameter Q during creep crack growth is obtained by FEM.
► A C*–Q approach is employed to characterize the creep crack growth rate.