Three-dimensional finite element analyses of in-plane and out-of-plane creep crack-tip constraints for different specimen geometries

Abstract

Based on extensive three-dimensional finite element analyses, the creep crack-tip constraints for three specimen geometries (C(T), SEN(T) and M(T)) were quantified by using three constraint parameters (namely R*, h and Tz) for 316H steel at 550°C and steady-state power law creep. The three parameters were comparatively analyzed with respect to their capabilities for characterizing in-plane and out-of-plane creep constraints as well as the interaction between them. The results show that the specimen geometries with higher constraint strengthen the out-of-plane creep constraint effect. The parameters R* and h can quantify in-plane creep constraint, but they are inadequate to characterize higher out-of-plane creep constraint. The Tz can adequately incorporate out-of-plane creep constraint effect.