The Wear Mechanism Of High-Speed Wheel Out-of-Round And Bogie’s Vibration Insolution Design In Mid-high Frequency

Nowadays more and more people consider high-speed trains to be comfortable, safe, low and clean energy consumption transportation tool. However, as their operation speed and operation mileage increased, the polygonal wear of their wheels become more and more serious. Serious wheel polygon wear can lead to high wheel-rail rolling impact and the fierce vibrations of vehicle-track system, which influence the running safty of train. Therefore, field tests with numerical simulation are carrieded out to investigate the main cause of wheel higher-order polygon wear formation. The improvement measures of the bogie in order to reduce the vibration are also discussed. It is noted that the present results are helpful in slowing down the development of the wheel polygon wear, and the some results may also provide a reference for structure improvement of the existing bogies and structure design of the new high-speed bogies. The main work and conclusions are as follows:In the field tests, the wheel wear status and the vibrations of the key components of the bogie are monitored focusing on finding the relationship between the abnormal vibration of axle box and non-circular wear of the wheels. Test result shows that the mid-and high-frequency vibrations of high-speed bogies are very notable, especially in the 560-590 Hz range, which are very close to the passing frequencies corresponding to the 22nd to 23th polygonal wear of the wheel.In order to investigate the main cause of wheel higher-order polygon formation, modes of the wheelset and the bogie frame are calculated by using finite element software ANSYS. The numerical results show that the coupled modes of bogie side beam local movement and the third order bending of wheelset maybe the main reason for the wheel higher-order polygon wear. The vibration transmissibility of the primary suspension is analyzed through the test by using hammer. The test results show that the vibration isolations of the primary suspension are bad in the frequency band of 550-560Hz, in which vibrations are easier to translate from axle box to bogie frame. At last, the harmonic frequency vibrations are simulated by using the Matlab. The numerical results show that wheel initial polygon wear can excite the harmonic frequency vibrations in the wide frequcny band, which can accelerate the developments-of wheel polygon.A 3D flexible model of a whole bogie is developed using the explicit finite element (FE) method, which considers the flexible modals of the bogie frame, wheelsets and double coil springs. The analyzed frequency ranges up to 800 Hz. The modal parameters and vibration responses are verified compared to the test data. Based on the verified FEM calculation model, the effect of the polygonal wear characteristics, such as roughness level, polygon order and polygon phase of two wheels of wheelset, on mid-high frequency vibrations are predicted. Based on the bogie FE model, the vertical vibration responses of the axle boxes and the bogie frame are obtained using harmonic analysis in frequency domains. The results show that the magnitudes of serious vibrations on the axle box is close to that of the bogie frame in the frequency band of 520～560 Hz. According to the peak freqency bands, the vibration deformations mainly include the bogie side beam local movements and the third-order bending of wheelset.In order to reduce the coupled resonance of the axle and the bogie frame in the frequency band of 520～560 Hz, the effect of the stiffness and damping of the primary suspensions, wheelset axle diameter and bogie frame strength on the vibration transmissibility and their deformation combination are discussed carefully. The numerical results show that the resonance peaks in high frequency range can be reduced by reducing the stiffness of axle box rotary arm joint, increasing the damping of axle box rotary arm joint, changing the wheelset axle diameter or strengthening the bogie frame location.