小半径曲线钢轨波磨激扰下列车车内振动噪声特性

为探究小半径曲线钢轨波磨与车内振动噪声的关系，以高铁站区线路中出现的钢轨波磨为对象，开展了实车试验与轨面平直度现场测试；采用同步压缩小波变换提取了车厢内部振动与噪声信号的时频特征，并引入全局小波功率谱和小波能量比对信号进行量化分析；建立了波磨严重程度与车厢内振动噪声水平的关联关系，对比了车体与走行部构件之间动力响应的差异，探讨了波磨所在曲线半径对车内振动噪声的影响。研究结果表明：在小半径曲线地段，车厢内振动与噪声信号的优势频率为500～550 Hz,与钢轨波磨引起的轮轨冲击频率一致，且该频段的能量在波磨严重区段愈加显著；轴箱与转向架构架振动信号在500～550 Hz频带也存在能量峰值，而轴箱振动信号中出现的330、1 046 Hz等峰值频率被一系悬挂有效过滤，使得构架振动响应中未见此频率成分；在车厢内采集的各项信号中，车体垂向振动响应与钢轨波磨沿线路里程的分布特征最为相关，而车内噪声、纵/横向振动、侧滚运动的相关性次之，摇头运动的相关性最低；与直线和大半径曲线相比，小半径曲线区段的车体振动与噪声水平受钢轨波磨的影响更为显著。

Train interior vibration and noise characteristics induced by rail corrugation with small-radius curves

To explore the relationship between rail corrugation with small-radius curves and train interior vibration and noise, the rail corrugation occurring on the lines of a high-speed rail station was taken as an object, the train tests were carried out, and the rail surface irregularity was measured on site. The time-frequency characteristics of vibration and noise signals inside the carriages were extracted by using the synchro-squeezed wavelet transform. The global wavelet power spectrum and wavelet energy ratio were introduced to quantify and analyze the signals. The correlation between the severity of corrugation and the vibration and noise levels inside the carriages was established. The difference of dynamic responses between the car body as well as the running components and parts was compared. The influence of the curve radius of the corrugation on the train interior vibration and noise was investigated. Analysis results indicate that the vibration and noise signals become dominant at the frequency of 500-550 Hz at the sections with small-radius curves, which coincides with the impact frequency of wheel-rail induced by the rail corrugation. Further, the energy in this frequency band raises rapidly at the sections with the exacerbation of rail corrugation. The vibration signals of the axle box and bogie frame also have energy peaks in the frequency band of 500-550 Hz, while the peak frequencies of the vibration signals of the axle box such as 330 and 1 046 Hz are effectively filtered by the primary suspensions so that these frequency components are not observed from the vibration responses of the bogie frame. Regarding all signals collected within the carriages, the highest correlation can be observed between the distribution characteristics of vertical vibration response of the car body and the rail corrugation along the lines and mileage. The correlation among the noise inside the carriage, longitudinal vibration/lateral vibration and side-rolling rotation takes the second place, while the yaw rotation is less affected. Compared with the straight lines and large-radius curves, the vibration of the train body and noise levels at the sections with small-radius curves are more significantly affected by the rail corrugation.