SURFACE CRACKS IN TOROIDAL SHELLS

Toroidal shells containing a surface crack and subjected to various sy mmetric and antisymmetric loading conditions are considered. A singula r integral formulation of a through crack located along a principal li ne of curvature of a shell is used along with the line spring model to treat the surface crack problem. Transverse shear deformations are ta ken into account in the shell theory. Locating the crack along a line or principal curvature uncouples the symmetric mode I deformations fro m the antisymmetric mode II and III deformations, which are inherently coupled. Mode I loadings considered include membrane loading and bend ing, while the mode II and III cases include in plane shear, twisting and transverse shear. In addition to these loadings, residual stresses resulting in mode I deformations are considered. Stress intensity fac tors for the various loadings are given for shell geometries represent ative of spherical caps, cylindrical pipes and pipe elbows for a numbe r of crack locations.