NUMERICAL INVESTIGATION OF CRACK ORIENTATION IN THE FRETTING FATIGUE OF A FLAT ROUNDED CONTACT

The growth of slant cracks by fretting fatigue of a half plane in contact with a flat rounded pad was studied. The mode I and mode II stress intensity factors for cracks of various lengths and directions were calculated using the semi-analytical method of the distribution of dislocations, and their cumulative effect on the crack growth was investigated using the strain energy density criterion.  The results showed dominance of mode I fracture on crack growth, and based on the observation of strain energy density factor versus crack orientation, the results also suggest that depending on the crack length, the most critical orientations of cracks are at 00 to 200 outward the contact zone.  Good agreement was observed between the results of this semi-analytical approach, and the corresponding results from finite element method, for selected crack lengths and orientations.