Wheel/rail dynamic interaction induced by polygonal wear of locomotive wheels

Serious wheel polygonal wear usually causes drastic wheel/rail interactions, which threats the running safety of railway vehicles. This paper presents an investigation into the effect of polygonal wear of heavy-haul locomotive wheels on the dynamic performance and wheel/rail interactions through extensive on-site tests and numerical simulations, in which a special attention is paid to locomotive vibrations and dynamic wheel/rail tangential forces. The measured results conducted on two objective locomotives were firstly compared, including the characteristics of wheel polygonal wear and locomotive vibrations in vertical, longitudinal and lateral directions. A 3D heavy-haul train-track coupled dynamic model was then formulated to investigate wheel/rail dynamic interaction induced by polygonal wear of locomotive wheels. A low adhesion zone (LAZ) and a PI-based anti-slip control algorithm were embedded into the dynamic model to analyse the effects of wheel polygonal wear on wheel/rail longitudinal and lateral interactions under normal and low adhesion conditions. The results show that the severe wheel polygonal wear affects not only the vertical but also the longitudinal performance of the wheel/rail system notably. The wheel high-order polygonal wear has a conspicuous effect on longitudinal, lateral and vertical vibrations of locomotive system components.