Characterization of creep fatigue crack growth behavior using the C(t) parameter

Although the problem of creep crack growth under constant loading has received much experimental, analytical and computational attention, most practical applications involve creep-fatigue crack growth. In this research, an experimental and computational study of creep-fatigue crack growth behavior of 1.25Cr-0.5Mo steel at 538In creep-fatigue crack growth experiments, the hold time ranges from 0 to 24 hours with intermediate conditions of 10 seconds, 98 seconds, 10 minutes and 15 minutes. The (da/dt)Finite element simulations of the first few cycles of several histories with different hold times with and without overload are presented to clarify the nature of the cyclic plasticity and the subsequent transient retardation of the creep rate in the crack tip region. The constitutive laws employed include kinematic hardening bounding surface plasticity suitable for cyclic loading and decoupled secondary creep. Based on the numerical results, a new...