Distribution of contact stresses along a worn fretting surface

Abstract

Previous investigations have established fracture mechanics as a useful tool in quantitative studies of fretting fatigue crack behaviour. One major problem in such analyses is the difficulty in determining the distribution of stresses in the fretting contact. In this paper the contact pressure is expected to be uniform due to the wear of contact surfaces taking place in fretting. Based on this assumption analytical expressions for the stick zone, the slip amplitude and the distribution of shear stresses are found. It is seen that the distribution of contact shear stresses varies considerably with the size and location of the stick zone. This in turn affects the loading of the fretting cracks in terms of stress intensity factors, hence the behaviour of these cracks will vary with the degree of partial slip. When full slip takes place, the distributions of contact pressure and shear stress are uniform according to the model presented here.