以莫喀高铁为工程背景,以WJ-8型扣件胶垫为对象,测试胶垫静刚度随温度降低的变化,分析胶垫刚度的温变特性;建立车辆轨道垂向耦合系统动力学模型,分析在-48℃和20℃两种温度下胶垫静刚度对高铁列车以400 km/h的速度运行所产生的动力响应的影响规律.结果表明:轨下胶垫的刚度随温度降低而增大,-48℃时的静刚度相比20℃时增幅51.1%;不同环境温度下,车辆运行平稳性受到影响较小而轮对垂向振动加速度受到影响较大;低温条件下垂向轮轨力和轮重减载率较常温时前者增幅8.19%而后者增幅达14.13%;因在-48℃低温条件下轮重减载率已接近于限值,为保证车辆运行安全性,建议采用耐低温类型的扣件胶垫.%With reference to Mo-Ka high-speed railway project, an indoor test is conducted on WJ-8 fastener to analysis the change of the rail pad static stiffness subject to temperature decreasing and to identify the temperature variant characteristics of rail pad stiffness. The vehicle-track vertical coupling dynamics model is then established to analyze the impact of rail pad static stiffness on wheel-rail response at the temperature of -48℃ and 20℃ respectively at the speed of 400 km/h. The results show that the static stiffness of the rail pad increases with temperature decreasing, the static stiffness is increased by 51. 1% at -48 ℃ compared with that at 20 ℃; the change of temperature has a small impact on the vehicle running smoothness but a relatively big impact on the vertical vibration acceleration of the wheel set;at low temperature, the vertical wheel-rail force is increased by 8. 19% compared with the force at ambient temperature, while the wheel load reduction rate is increased by 14. 13%. Because the wheel load reduction rate reaches the limit at -48℃, low-temperature-resistant rail pads are recommended in order to ensure the safety of the vehicle.
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