Vossloh300扣件阻尼频变对高铁高频振动的影响研究

以Vossloh300扣件胶垫为研究对象,利用配备温度箱的万能试验机测得其在-60℃~20℃的耗能刚度。在试验基础上结合温频等效原理及车辆-轨道垂向耦合Timoshenko梁模型,在频域内探究该型扣件频变阻尼对高铁轮轨系统动力特性的影响。结果表明:Vossloh300扣件胶垫在20℃,4 Hz激振频率下阻尼系数约152.2 kN/（m·s-1）。Vossloh300扣件频变阻尼主要影响车辆-轨道垂向耦合系统1/3倍频中心频率22 Hz以上的振动响应,即:①增大车辆和轨道系统22~56 Hz的中高频振动,同时减小其60~256 Hz的高频振动;②在512~1 500 Hz范围内,钢轨垂向1/3倍频加速度振级最大值增大了5 dB,同时,扣件力1/3倍频幅值最大值减小了92%。因此,为精确预测高速铁路车辆及轮下结构随机振动响应,需考虑扣件胶垫的阻尼频变特性。

Influence of Frequency-dependent Damping of Vossloh 300 Fastener on High-frequency Vibration of High-speed Train

Taking Vossloh300 fastener pad as the study object, its energy consumption stiffness at the temperature between -60℃~20℃ was measured with universal testing machine equipped with temperature box. On this basis, together with temperature-frequency superposition principle and Timoshenko beam model for vehicle-track coupling dynamics, how the frequency-dependent damping of such fastener influences the dynamic characteristics of the wheel-track system, was explored in the frequency domain. The results show that, for Vossloh300 fastener pad, its damping coefficient is 152.2 kN/(m·s-1) at 20℃ and 4Hz excitation frequency. The frequency-dependent damping of Vossloh300 has primary effect on the vibration response of vehicle-track vertical coupling system at 1/3 OCT with center frequency above 22 Hz:①the middle-high frequency vibration at 22~56 Hz of vehicle-track system is increased, but the high frequency vibration at 60~256 Hz decreased; ②in the range of 512~1500 Hz, the maximum 1/3 OCT acceleration-vibration level perpendicular to the track is increased by 5 dB, at the same time, the maximum 1/3 OCT amplitude of fastener force decreased by 92%. Therefore, to predict accurately the random vibration response of high-speed railway vehicle and the structure under wheel, it is required to consider the frequency-dependent damping characteristics of fastener pad.