The detrimental effects of hollow wear––field experiences and numerical simulations

The current paper deals with the influence of hollow wheels on the risk for surface initiated rolling contact fatigue. To this end, the problem is introduced and field experiences are outlined. The problem is then analyzed more in detail through numerical simulations of bogie curving. Quasi-static simulations featuring several hollowed profiles are carried out to give a first rough estimation of the severity. Simulations of the dynamic curving behaviour are carried out for a selected case to provide a more detailed image of the detrimental nature of wear hollowing. These are complemented by a FE-simulation for a detailed study of the contact configuration. Finally, the results are discussed and conclusions are drawn. In particular it is shown how high rolling contact fatigue impact is associated with high lateral forces and a narrow contact patch. It is also seen to be likely that quasi-static simulations underestimate fatigue impact and that the current practice of characterizing hollow wear by the wear depth is flawed.