Sensitivity Analysis of SCC Crack Extension Simulation

For the preliminary investigation of realistic SCC crack extension behavior, several crack extension simulation methods were applied to example problems. As for a mesh division procedure, two kinds of methods were employed. One is a conventional one which needs new mesh generation of finite element (FE) models following crack extension and the other one is X-FEM without new FE mesh generation. Also the effects of crack extension contained within the weld material and the crack growth rate dependence on the crack extension direction at the weld joint were considered. Under hypothetical liner stress distribution, the stress intensity factors from the FE analyses by the conventional mesh division procedure and X-FEM agreed well with those from the stress intensity factor K equations of a hand book in the case of semi-elliptical and semi circular cracks. As for the crack extension analysis, consideration of the direction dependent crack growth rate and limited crack extension within the hypothetical shaped weld groove boundary gave a large effect on the crack extension amount in the thickness direction.© 2011 ASME