Notched double-curvature shells with cracks under pulsating internal pressure

摘要

In the present paper, a double-curvature thin-walled shell with a surface crack starting from the root of an external circular-arc notch under cyclic loading is examined. The stress-intensity factor (SIF) along the elliptical-arc crack front is computed through a three-dimensional finite element analysis, for several elementary polynomial stress distributions perpendicular to the crack faces. By using the power series expansion of the actual stress field and the superposition principle, an approximate expression of the SIF in the case of a generic complex loading can be determined. Then the effect of the notch stress concentration on the SIF (and on the fatigue) behaviour is analysed for both cylindrical and spherical shells under (pulsating) internal pressure.