地铁道岔区段道床板振动特性分析

为了研究地铁道岔区段道床板振动特性,并且为减振降噪设计提供理论参考,以地铁道岔区段为研究对象,以实测轨道不平顺数据为基准,建立道岔区段仿真模型,进行计算。通过时域、频域及模态分析,得出不同工况(速度)下道岔区段道床板振动响应。结果表明:相同速度下,道床板尖轨位置的垂向振动响应要大于心轨位置,并且其垂向振动加速度峰值是心轨位置的近2倍左右。随着列车通过速度的提高,无论尖轨还是心轨位置,道床板的振动响应都会逐渐增强。道床板尖轨位置垂向振动对应的主频为4,80 Hz及140 Hz,在80 Hz,道床板产生低频垂向振动最大。而道床板心轨位置垂向振动对应的主频为5,75 Hz及145 Hz,并且在75 Hz处,道床板产生低频垂向振动最大。模态分析时,发现对道床板尖轨和心轨位置振动影响最大的是各阶连续弯曲和混合扭弯模态。

Analysis of Vibration Characteristics of Track Beds in Subway Turnout Zone

In order to study the vibration characteristics of the track bed in the metro turnout zone and provide a theoretical reference for the design of vibration and noise reduction, this paper takes the subway turnout zone as the research object, and builds the simulation model of the turnout zone based on the measured track irregularity data. Through time domain, frequency domain and modal analysis, the vibration response of the track bed in the turnout zone under different working conditions(speeds) is obtained. The results show that the vertical vibration response of the point rail position of the track bed is greater than that of the core rail at the same speed, and the vertical vibration acceleration peak is about 2 times of the core rail position. As the train speed increases, the vibration response of the track bed will gradually increase regardless of the point rail or the core rail position. The main frequencies corresponding to the vertical vibration of the point rail position of the track bed are 4 Hz, 80 Hz and 140 Hz. At 80 Hz, the low-frequency vertical vibration of the track bed is the largest. The main frequencies corresponding to the vertical vibration of the point rail position are 5 Hz, 75 Hz and 145 Hz;and at 75 Hz, the track bed produces the lowest vertical vibration. The modal analysis concludes found that the most influential vibration effect on the point rail and core rail position of the track bed is the continuous bending and mixed twisting modes of each order.