Experiments on crack propagation and threshold at defects in press-fits of railway axles

In this paper, after a preliminary presentation of the results obtained by a new criterion for predicting the non-propagation of cracks under rolling contact fatigue conditions, a new series of experiments on full-scale axle press-fits containing artificial defects is presented and discussed. Results show the modified Dang Van criterion is adequate for describing the development of natural cracks and cracks from artificial defects. The latter, characterized by a depth of 250 - 350µm, are competitors of fretting cracks naturally developed from surface scars and surface damage.