Effect of wheel initial state on the growth of polygonal wear on high-speed trains

High-order wheel polygonal wear (PW) occurs widely on China's high-speed trains, deteriorating ride quality and greatly shortening the service life of vehicle/track components and infrastructure. No satisfactory solution has been provided to prevent high-order PW formation, even though considerable research has been conducted on its growth mechanism. Against this background, to increase operating mileage before high-order PW formation, it is of great importance to understand the effect of the wheel's initial state on the development of highorder PW. This study combines a coupled vehicle/track dynamic model and the Archard wear model to build a long-term PW iterative simulation procedure. The growth process of high-order PW is first reproduced under the nominal parameters; then, the effects of the wheel initial state such as wheel flat, wheel initial eccentric, and residual high-order PW after re-profiling are investigated by comparing evolution of high-order PW initiating from these different states. Results suggest that the wheel flat increases excitation of the rail localized bending resonance and promotes high-order PW growth around the initial flat. Wheel eccentricity has a negligible influence on high-order PW, but mass eccentricity can exacerbate the rise in wheel runout. Moreover, the residual high-order PW after re-profiling forces the PW to form and develop on the adjacent wheel within a short mileage by transmitting vibrations via the rail. It is thus necessary to restrict the wheel flat and residual PW after reprofiling to a controllable level to postpone high-order PW recurrence.