Fatigue strength assessment of initial semi-elliptical cracks located at a hole

Abstract

In the present paper, the residual strength of a pin-loaded lug and a finite plate, both with a semi-elliptical crack emanating from a hole, is examined. A new analytical methodology, based on Fracture Mechanics concepts, is proposed to analyse the crack propagation process in terms of life estimation and crack front evolution. Firstly, the stress field and the stress intensity factor are computed by applying both analytical and numerical approaches. Then, the two-parameter driving force model proposed by Kujawski is implemented for the fatigue life estimation and the crack front evolution. The validity of model here employed is assessed through the comparison between crack growth calculations and experimental data available in the literature, such comparison shows a quite good correlation for the crack and geometrical configurations here examined.