以Vossloh300扣件胶垫为研究对象,通过使用配备温度箱的万能试验机,测试其在-60~20℃温度范围内静刚度值;在上述实验的基础上,利用多刚体动力学软件建立车轨耦合模型,探究该型扣件胶垫温变刚度对高铁列车动力特性的影响。实验结果显示:Vossloh300扣件胶垫刚度在-40~20℃温度域内具有较好的温度稳定性,-40℃胶垫静刚度为26.91 kN/mm,较20℃的22.40 kN/mm仅有20.4%的增长;当温度低于-40℃时,该扣件胶垫刚度随温度降低急剧增长。仿真分析表明:扣件胶垫刚度的温变性对高速列车脱轨系数影响不大,但对轮重减载率的影响十分明显:环境温度为-48℃时轮重减载率的最大值0.585较20℃时轮重减载率最大值0.469有24.73%的增长,可见环境温度继续降低时轮重减载率将成为影响行车安全的主要因素之一。
This article takes vossloh300 fastener pad as the research object and measures the fastener pad static stiffness values in the temperature range of-60 ~ 20 ℃ by using the universal testing machine equipped with temperature box. On the basis of the above experiment,multi-body dynamics software is used to establish a vehicle-rail coupling model to explore the effect of temperature-dependent stiffness of rail pads on dynamic characteristics ofthe high-speed train. Experimental results show that vossloh300 fastener pad has good temperature stability in the temperature range of-40 ~ 20 ℃,and the fastener pad static stiffness at-40 ℃ is26. 91 kN/mm,only 20. 4% more than the value at 20 ℃( 22. 40 kN/mm); when the temperature is lower than-40 ℃,the fastener pad stiffness grows sharply with the temperature declining. Simulation analysis indicates that temperature-dependent stiffness has little influence on derailment coefficient,but has a significant impact on wheel unloading rate: the maximum wheel unloading rate at-48 ℃ is 0. 585,which is 24. 73% more than the value at 20 ℃. It can be seen that the wheel unloading rate becomes one of the main factors effecting traffic safety as the ambient temperature continues to drop.