Stress intensity factor for an eccentric circular inner crack in a round bar subjected to tensile loading

Abstract

In this paper, stress intensity factor (SIF) was calculated in a bar subjected to tensile loading, considering a circular inner crack that exhibited certain eccentricity in relation to the cylinder axis. The computation was performed by means of the finite element method (FEM) using a three dimensional (3D) model and the J-integral, the analyzed variables being the diameter and the eccentricity of the circular inner crack. Results show that the SIF is higher at the point of the crack front closest to the bar surface and that an increase of relative crack eccentricity or of relative crack diameter raises the difference between the SIF values at the crack point closest to the bar surface and the crack point furthest from it, thus the existence of eccentricity in the initial crack leads to an increase of such a parameter when fatigue propagation occurs.