弹性短轨枕空吊对车辆-轨道系统的动力学影响分析

Dynamics Analysis of Voided Elastic Shorter Sleeper's Influence over Vehicle Track System

弹性短轨枕减振轨道是城市轨道交通所采用的经济有效的减振措施之一,但由于轨枕空吊的影响,近年来在工程中的用量急剧下降。采用车辆-轨道耦合动力学理论,建立可以考虑单侧轨枕空吊的车辆-轨道空间耦合振动模型,对城市轨道交通弹性短轨枕轨道轨枕空吊引起的车辆、轨道系统的振动响应进行理论分析。结果表明,弹性短轨枕空吊对钢轨扣件、轨枕的动力学影响最为显著,其次是轮轨力,对车体振动的影响为最小。若出现2根以上轨枕的连续空吊,则钢轨扣件系统受力会超出设计允许范围。通过轮轨力或车辆振动参数对轨枕空吊不易检测或识别。

Elastic shorter sleeper track is an economical and effective measure to isolate the train induced vibration in urban rail transit construction, but duc to the negative in- fluence of the voided sleepers, the use of elastic shorter- sleeper track has declined sharply in recent years. Based on the vehicle/track coupling dynamic theory, a vehicle/track coupling vibration model that could simulate the effects of unilateral voided elastic shorter sleepers is established. The dynamic responses of the vehicle/track system with voided elastic shorter sleepers are investigated. It shows that the voided elastic shorter sleepers greatly affects the dynamic response of fastens and sleepers rather than wheel/rail forces and vehicle system. When the number of voided sleepers is more than 2, the stress on track fastens would exceed the designed allowable range. It is inadvisable to use the dynamic response of wheel/rail forces and vehicle sys- tem to detect or identify the voided elastic shorter sleepers.