Influence of mass distribution of rail damper on dynamic performance
To analyze the effect of rail dampers with different resonant mass distribution in the damping block,the methods of finite element simulation and platform testing were integrated to analyze the difference in typical frequency and rail vibration decay rate of rail dampers with different mass distribution.Then two test sections were selected,while the on-site testing method was used to analyze the performance of rail dampers on rail vibration and trackside noise mitigation under the isolation mat floating slab track and damping fastener track.The main research results are drawn as follows.The mass distribution in the damping block affects the modal frequencies,effective frequency band,and vibration absorption efficiency.The vertical/lateral first-order modal frequency is determined by the thickness of the upper mass and the adjacent elastic layer,and the frequency with the highest vibration absorption ability is determined by the total mass and the elastic layer thickness near the rail.The modal frequencies of the rail damper approximate to the peak frequencies of vertical vibration decay rate in the platform tests.The mass distribution in the damping block can be optimized according to the modal frequency and effective mass ratio.After installing the rail dampers with different effective mass,the maximum vertical vibration decay rate of rail in the platform increases from 0.53 dB/m to 3.54 dB/m and to 4.07 dB/m,and the maximum increase rates of rail vibration decay rates are 1143％ and 2023％.According to the field test results,in the rail corrugation section of the floating slab track with under slab mat,the rail damper can reduce the total level of rail vibration acceleration at 1～1000 Hz by 5.6 dB,reduce the vibration acceleration level at main frequency of corrugation by 2.2～5.8 dB,and effectively decrease the development rate of rail surface roughness.In the section of high-level vibration damping fastener,the rail damper can reduce the trackside noise by 6.1 dB(A).The research results can provide reference for the design and optimization of rail damper.
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维普
