Experimental and numerical investigation of effect of size, position and geometry of some cutouts on fatigue life and crack growth path on AISI1045 steel plate

The main factor in determining path and rate in fatigue crack growth (FCG) problems is the stress field around the crack tip that is defined as stress intensity factor (SIF). Cutouts cause a stress concentration that depends on their size and geometry. This stress concentration can affect the stress field near the crack tip vicinity and deviates the FCG path. In this paper in order to study the effect of cutout parameters on FCG, first, a taguchi statistical analysis is used. Then, controlling and changing the FCG path and rate in specimens with different cutouts are studied. The results show that the size and position of cutouts are the most effective parameters on the crack growth path. According to the cutout's features, an increase or decrease in fatigue life can be expected. An effective range for the distance between a cutout and a crack tip was determined. To verify the results of the extended finite element method (XFEM), the mode I SIF was obtained experimentally and compared with XFEM results. It was concluded that numerical results are in such a good agreement with experimental results.