Wheel Out-of-Roundness Identification Approach Based on Axlebox High-Frequency Vibrations

In order to realise the real-time detection of wheel out-of-roundness (OOR) for high-speed trains, the spectral characteristics and mapping relationship between the axlebox high-frequency vibration and the wheel OOR are studied. The amplitude and order of the wheel OOR are identified using the frequency-domain integration method. Firstly, manifestations of the wheel polygonisation, rail corrugation and track modes of China high-speed railways are investigated through static measurements and laboratory experiments. Secondly, the time-frequency characteristics and evolution principle of the bogie axlebox vibrations are obtained through the long-term operation performance tracking test of a high-speed train. Finally, taking the 20th order wheel polygonisation as the research object, an identification approach of the wheel OOR order and amplitude is proposed based on the frequency-domain integration method. The results show that the third-order bending modal frequency of the China railway track system Ⅱ (CRTS-Ⅱ) track slab is 592 Hz. When the train is running at a speed of 300 km/h, the response frequencies due to the 20th-order wheel polygonisation and the rail corrugation with a wavelength of 136 mm are 580 and 613 Hz, respectively. The dominant frequencies of rail mode, wheel polygonisation and rail corrugation are relatively concentrated. The amplitude of high-frequency vibration of axlebox increases with the increase of vehicle speed and mileage after re-profiling. Theoretically, the amplitude and order of the wheel OOR can be identified by the integration of accelerations in the frequency domain. The relative error between the identified 20th-order wheel OOR results based on the field-tested axlebox acceleration and the static measured values is less than 5%.