Two approaches to taking nonsingular T-stresses into account in the criteria of fracture mechanics for bodies with notches

Abstract

Two possible models and criterion equations of fracture mechanics for bodies with notches taking into account nonsingular expansion terms of stresses at the notch (crack) apex based on crack-growth resistance diagrams and a master curve are considered. A criterion equation of a generalized crack-growth resistance diagram admissible for a body with a crack and a notch and taking into account the changes in the degree of strain constraint at the notch apex due to finiteness of its apex radius rounding and a nonsingular stress component (T-stresses) is given. The notion of effective T-stresses determined using averaging of T-stresses in front of the notch apex in the pre-fracture zone characterized by effective scattering in introduced. A basic dependence of fracturing viscosity in the function of effective T-stresses (a master curve) of pipe steel is constructed for the given notch geometry.