Crack initiation at V-notch tip subjected to in-plane mixed mode loading: An application of the fictitious notch rounding concept

Abstract

ABSTRACT. The fictitious notch rounding concept is applied for the first time to V-notches with root hole subjected to in-plane mixed mode loading. Out-of-bisector crack propagation is taken into account. The fictitious notch radius is determined as a function of the real notch radius the microstructural support length and the notch opening angle. Due to the complexity of the problem, a method based on the simple normal stress failure criterion has been used. It is combined with the maximum tangential stress criterion to determine the crack propagation angle. An analytical method based on Neuber's procedure has been developed. The method provides the values of the microstructural support factor as a function of the mode ratio and the notch opening angle. The support factor is considered to be independent of the microstructural support length. Finally, for comparison, the support factor is determined on a purely numerical basis by iterative analysis of FE models.

Report of Committee III.2: Fatigue and fracture

“…For mixed mode-I and -II response conditions at V-shaped notches with a root hole, the loading & response and geometry dependent support factor have been investigated analytically and numerically adopting a maximum tangential stress based crack angle in order to enable Neuber's stress averaging along the crack path (Berto, 2015b).…”