Research On Elastic Wheel-rail Coupling System’s Vibration Characteristics Of Metro

Now days, with the rapid development of urban rail transit, requirements on vibration and noise reduction become more and more strict, as a result, different types of vibration reduction track are widely used, while problems like wheel-rail vibration and noise, rail corrugation and rail fastener snapping, etc, arise, which lead to a significant increase on the workload and cost of maintenance, and threaten the safety of operation. The effective control on wheel-rail vibration requires the grasp of the vibration property while coupled with elastic wheel and the dynamic property during the actual operation. Based on the summarizing and induction of the recent national and international research on the wheel-rail vibration, and considering the widely used track form in our country, in this paper, the vertical vibration transfer property and dynamic property of the common wheel-rail system were studied from the perspective of coupling vibration of the elastic wheel-rail. The main research contents and conclusions are as follows:(1) The finite element model of elastic vehicle-rail coupling system is established, by analyzing on the vibration transfer property, it is found that, from 419Hz to 450Hz, under the vertical excitation, only the horizontal stretching vibration of the wheel is found. No obvious changes on the form of the track due to the coupling of the track was found.(2) From 320Hz to 380Hz for the common slab track, from 290Hz to 402Hz for ladder track and from 300Hz to 380Hz for floating slab track, the resonances of rail-wheel, rail-track (sleeper) were both found. Which due to the fact that in this frequency range, there exist an interactions of’hammer peening’between the rail and the wheel, which may lead to plastic deformation of the rail and the wheel, and then give rise to the rail corrugation.(3) Due to the influence of the wheel/rail vibration, the amplitude of the rail fastener force usually changes greatly, which usually cause fatigue of rail fastener. Moreover, the anti-resonance of the rail and track (sleeper) will enhance the uplift force of the rail fastener, the vibration deformation of the wheels also enhance the transverse effects of the rail. All of these factors, can easily cause the snapping of the rail fastener.(4) For these three type of tracks, in the main vibration frequency domain, the vibration of the rail increases with the incensement of the velocity, which intensifies the vibration and the noise, and also easily leads to the resonance and anti-resonance and cause the rail corrugation; the main vibration frequency of the ladder track is around 134Hz, the frequency-response function of the rail hammer peening test shows that the vibration peak of the sleeper and the rail is around 134Hz, which coincide with the frequency (134Hz) where the rail corrugation occurs for the ladder track, which means that the wheel/rail vibration is the main reason for the rail corrugation of the ladder track, moreover, the speed control can not control the vibration around 134Hz effectively.(5) The peak value of the wheel/rail vibration acceleration under the time response is mainly caused by the vibration of the wheel/rail around the main frequency.