Surface cracks in shells under different hoop stress distributions

An external surface flaw in a thin-walled shell subjected to various types of elementary hoop stress distributions is considered. The surface defect i s assumed to lie on one of the principal curvature planes of the shell, and to present an elliptical-are shape. The stress-intensity factors (SIFs) al ong the crack front for the above loadings on the crack faces are derived b y applying the finite element method. Then approximate values of SIF in the case of a cracked pressure vessel are computed by employing the results fo r elementary stress distributions together with the superposition principle and the power series expansion of the actual hoop stress. (C) 2000 Elsevie r Science Ltd. All rights reserved.