Thermal fatigue crack propagation in massive cylinders during their cyclic heating

Abstract

Processes that reduce the level of maximum unsteady stresses during thermal fatigue crack propagation in massive bodies during their convective cyclic heating are considered. It is shown that during crack propagation, the stress intensity factor K1 increases initially to a certain limit K1max and then decreases. The factor K1max depends on the initial and boundary conditions of heat exchange as well as on the rates of decrease in the maximum stresses during thermal fatigue crack propagation. It is shown that the asymmetry of boundary and initial conditions of heat exchange can contribute to either acceleration or retardation of crack propagation depending on the material properties and heating conditions.