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.%以Vossloh300扣件胶垫为研究对象,利用昊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512～1500 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.
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