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The high-frequency excitation generated by the wheel polygon seriously affects the safety of the train. In order to explore the evolution mechanism of wheel polygonisation, a long-term prediction model of wheel circumferential wear on both sides of the wheelset is proposed. Based on a new updating strategy, the model is implemented by combining the coupled vehicle/track dynamic model and the wheel circumferential wear model. The wheel circumferential wear model is implemented by local tangential contact model FaStrip and USFD (a wear model proposed by The University of Sheffield). By analysing the measured data, five wheel circumferential states are summarised, which are employed as wheel non-circular excitations to analyse the evolution of the wheel polygons on both sides of the wheelset. The results show that the same order of the polygonal wheels on both sides of the wheelset is the main reason for the evolution of the order of polygonal wheels in integer multiples. When the circumferences of the wheels on both sides are in an asymmetric state, the wheels on both sides will interact with each other, and the final circumferences of the wheels will gradually evolve into mixed polygonal circumferences related to the initial orders. [ABSTRACT FROM AUTHOR]

A long-term tracking test was performed on a newly designed high-speed train with the nominal speed of 250 km/h. The wheel roughness and structural vibration were both recorded during two re-profiling cycles. The 3rd order polygonal wear was observed in the early stage. The vibration of the axlebox can be aggravated even at lower speed when the passing frequency of polygonal wear approaches the P2 resonance frequency. Subsequently, the 22nd–25th and 14th–15th order developed. The trend analysis suggests that the development of high-order polygonal wear is exponential-like. Moreover, a localised decline is explored during the development progress due to the change of route, which indicates the polygonal wear can be suppressed by reducing the proportion of constant-speed operation. It is also found that the acceleration amplitude of 550–650 Hz shows the most remarkable rise with the mileage, following the 300–400 Hz. However, there is a slight difference of characteristic frequency between the initially dominant peak and the finally developed order. The high-frequency vibration induced by high-order polygonal wear can be noticed on the entire vehicle, and it transmits between the adjacent wheels through the rail. [ABSTRACT FROM AUTHOR]