Effect of thermo-mechanical residual stresses on fatigue crack propagation

In this paper we present the influence of residual stresses on the behavior of fatigue cracks under thermo-mechanical loading. Propagation modeling is performed using the global stress intensity factor approach, which describes the simultaneous influence of residual stress field and applied stress on crack propagation. The residual stresses are generated by a thermal loading. These stresses are the result of incompatibilities of deformation related to the heterogeneity of the plastic deformation. They will be superimposed on the loading of fatigue and thus modify the average stress. These residual stresses relax under the effect of fatigue loading, by keeping the crack closed or open, according to the stress cycle