以减振垫层为研究对象,首先通过动态力学性能试验,基于高阶分数阶导数FVMP模型并结合温频等效原理,表征减振垫层的温频变特性;然后将该模型应用于车辆-CRTSIII板式无砟轨道垂向耦合系统中;最后分析了减振垫层温频变特性对轨道结构振动响应的影响.结果表明:温度和加载频率对减振垫层的动态力学性能有显著影响,高阶分数阶导数FVMP模型能准确表征这种动态力学行为.在时域响应中,轨道板位移和加速度在FVMP模型下计算的峰值明显大于Kelvin-Voigt(K-V)模型下的峰值.FVMP模型在各参考温度点下轨道板位移的响应呈现出随着温度的降低而减小的趋势,而轨道板加速度则呈现随着温度的降低而增大的趋势.在中高频段内,轨道板的响应表现为FVMP模型下的频域响应大于K-V模型下的频域响应,FVMP模型各参考温度点在该频段内轨道板的响应表现为随着温度的降低而减小的趋势.因此,为提高对轨道结构预测的准确性,有必要考虑减振垫层的温频变特性.

Taking the damping layer as the research object, first, by using the dynamic mechanical test, based on the high-order fractional derivative FVMP model, and in combination with the temperature-frequency equivalent principle, the temperature and frequency dependent properties of the damping layer was characterized. Then, the model was applied to the vehicle-CRTSIII slab ballastless track coupled system. Finally, the effect of the temperature and frequency dependent properties of the damping layer on track structure vibration response was analyzed. The results show that the temperature and the loading frequency have a significant impact on the dynamic mechanical properties on the damping layer and the high-order fractional derivative FVMP model can accurately characterize this property. In the time domain response, the peak values of the slab track displacement and the acceleration on the FVMP model are significantly larger than those on the K-V model. At each reference temperature point, the displacement response of the slab track on the FVMP model decreases with the decrease of temperature, while the acceleration of the slab track shows an opposite trend. In the middle and high frequency band, the frequency domain response of the slab track on the FVMP model are greater than those on the K-V model. At each reference temperature point, the response of the slab track on the FVMP model decreases with the decrease of the temperature. Therefore, in order to improve the accuracy of the track structure prediction, it is necessary to consider the temperature and frequency dependent properties of the damping layer.