A combination of the weight function method and the line spring model: A surface-cracked cylindrical shell subjected to stress gradients

Abstract

In this paper, the problem of a part-through crack with arbitrary loads on the crack faces is considered. By introducing the solution of the weight function for a two-dimensional edge crack, combined with the line spring model, the extra loads on crack faces can be represented as two equivalent quantities in terms of two-dimensional stress intensity factors. The problem for a cylindrical shell containing an axial inner surface crack subjected to stress gradients can then be reduced to two integral equations. The model is used to compute the stress intensity factors for four stress distributions—uniform, linear, quadratic and cubic—and the results give very good agreement with those obtained by the finite element method. The numerical results of the calculations for axial inner surface crack initiation in the shell subjected to thermal shock are also presented and discussed.