Thermal shock in a circumferentially cracked hollow cylinder with cladding

An analysis is presented which demonstrates the effect that cladding has on the thermal shock resistance of a circumferentially cracked hollow cylinder. The cladding, which in general may have different thermal properties from the base material, is assumed to be bonded to the inner wall of the hollow cylinder. The axisymmetric circumferential crack may either be embedded in the cylinder wall, typically underneath the clad, or may be an edge crack which passes through the clad and opens into the inner wall of the hollow cylinder. The mathematical formulation of the problem results in a singular integral equation of a well known type which is solved numerically. Results, which include transient temperature distributions, thermal stresses in the uncracked cylinder, and stress intensity factors as a function of time, are presented for various cladding thickness to cylinder wall thickness ratios. The numerical calculations concentrate on material properties and geometric configurations typically seen in nuclear pressure vessel applications. Results of particular interest are the transient stress intensity factors for various crack lengths and the comparison of maximum stress intensity factors in the clad cylinder with those in an unclad cylinder. (author)