Stress intensity factors of longitudinal surface cracks in a pipe with cladding under thermal loading

A pipe with cladding at the inner surface was considered. The pipe contains longitudinal semi–elliptical surface cracks originating in the cladding and mostly penetrating the cladding–base material interface. A thermoshock–loading of the component was assumed, and the time–dependent temperature and hoop stress distributions of the uncracked component were calculated. Following a procedure outlined by Mattheck et ul. (1983) using the weight function method stress intensity factors were evaluated at the deepest point and at the surface points of the cracks. Numerical values of the stress intensity factors are given at different time steps for various crack depths and crack lengths.