The effect of pipe bends on the stability of a circumferential through-wall crack in a type 304 stainless steel piping system. Exact theory accounting for axial strains in the piping segments

Simple models are used to simulate the effect of pipe bends on the stability of a circumferential through-wall crack in a type 304 stainless steel piping system that is subject to fixed displacement loadings, which are appropriate for an accident condition. The instability criterion is expressed in terms of the material tearing modulus TMAT and the applied tearing modulus TAPP (or the equivalent pipe length LEFF). In deriving an expression for LEFF, due account is taken of the axial strains in the piping segments, thereby extending the scope of earlier simpler analyses, in which such strains were ignored. The range of piping configurational parameters within which the simple approach can be used, is therefore defined. (author)