钢轨调频阻尼器质量分布与性能研究

Influence of mass distribution of rail damper on dynamic performance

为研究减振块中谐振质量分布对钢轨调频阻尼器动力性能的影响,采用数值仿真与平台试验相结合的方法,对比分析不同谐振质量体分布下的钢轨调频阻尼器在典型频率和钢轨振动衰减率方面的差异,并分别选取2个试验段,采用现场测试的方法对钢轨调频阻尼器在减振垫浮置板轨道、减振扣件轨道结构下的钢轨振动以及轨旁噪声控制效果进行分析。研究结果表明:减振块中质量体的分布影响减振块的模态频率、有效频段和分频吸振效能,上层质量体及邻近弹性层厚度确定了垂/横向1阶频率,近轨侧弹性层厚度及总质量确定了吸振能力最高的频率。钢轨调频阻尼器的模态频率与试验平台垂向振动衰减率峰值频率和衰减率增加的显著频段一致性较好,可根据模态频率和参振质量比对减振块质量分布进行优化。经平台试验,前十五阶模态参振质量低与高的两款钢轨调频阻尼器安装后,钢轨振动衰减率最大值由安装前的0.53dB/m分别提升至3.54dB/m和4.07dB/m,钢轨垂向振动衰减率分频最大增加率分别为1143%和2023%。由现场测试结果可知,安装调频钢轨阻尼器可降低减振垫浮置板轨道1~1000 Hz频段钢轨振动加速度总级值5.6 dB,降低波磨主频处分频振级2.2~5.8 dB,并有效降低钢轨表面粗糙度发展速度;安装后可降低高等级减振扣件轨道轨旁噪声6.1 dB(A)。研究成果可为钢轨调频阻尼器的结构设计及优化提供参考。

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.