25t轴重重载轨道扣件动参数对轮轨系统振动响应的影响研究

A Study on the Impact of the Dynamic Parameters of 25t Axle Load Heavy Haul Track Fasteners on the Vibration Response of the Wheel-Rail System

扣件系统刚度和阻尼是铁路轨道系统动力性能的关键设计参数,对于重载铁路系统而言合适的扣件刚度与阻尼设计参数将有助于缓解轮轨振动冲击,降低轮轨磨耗,提高系统部件的使用寿命。因此,本文以我国常用25t重载铁路为例,通过建立25t轴重货车车辆-轨道-有砟轨道耦合动力学模型,探讨了扣件动刚度与阻尼系数对轮轨振动响应特征的影响。主要研究结论如下:扣件系统动刚度对轮轨垂向力和钢轨垂向变形影响显著,轮轨垂向力最大值与扣件刚度呈正相关关系,与钢轨垂向位移为反比例关系;扣件阻尼系数主要影响轮轨垂向力的振动幅度,在低阻尼状态下甚至引起车轮的瞬时脱轨现象,但钢轨垂向变形影响不大。通过引入轮重减载率,并结合轮轨垂向力与钢轨垂向位移随扣件刚度与阻尼的变化规律,建议25t轴重重载扣件动刚度设计范围为30 kN/mm~90 kN/mm,阻尼系数设计范围为50 kN·s/m~100 kN·s/m。

The stiffness and damping of the fastening system are critical design parameters for the dynamic performance of railway track systems.Suitable fastening stiffness and damping parameters for heavy haul track can help mitigate wheel-rail vibration impacts,reduce wheel-rail wear,and extend the service life of system components.Therefore,this paper,using China's commonly used 25t heavy haul railway as an example,establishes a coupled dynamic model of a 25t axle load freight car vehicle-track-ballasted track system to investigate the influence of fastener dynamic stiffness and damping coefficients on the wheel-rail vibration response characteristics.The main research findings are as follows:Fastener system dynamic stiffness significantly affects the vertical force between the wheel and rail and the vertical deformation of the steel rail.The maximum vertical force between the wheel and rail is positively correlated with fastener stiffness and inversely proportional to the vertical displacement of the steel rail.Fastener damping coefficients primarily impact the vibration magnitude of the vertical force between the wheel and rail.In a low-damping state,it can even lead to the wheel momentarily derailing.However,the impact on the vertical deformation of the steel rail is relatively small.By introducing the wheel load reduction rate and considering the relationships between the vertical force between the wheel and rail and the vertical displacement of the steel rail with respect to fastener stiffness and damping,it is recommended that the design range for the dynamic stiffness of25t heavy haul fasteners should be 30 k N/mm to 90 kN/mm,and the design range for damping coefficients should be 50 kN·s/m to 100 kN·s/m.