高速铁路扣件失效对车辆-轨道耦合系统动态响应的影响

Effect of Fastener Failure of High-speed Railway on Dynamic Response of Vehicle-track Coupling System

以高速铁路无砟轨道W300-1型扣件为研究对象,考虑扣件系统弹条的扣压力和弹性垫板黏弹性材料的频率依赖性,建立表征扣件弹条非线性弹性和弹性垫板动态频变特性的扣件系统动力学模型。利用SIMPACK软件建立车辆-柔性轨道耦合动力学模型,通过设置0~5个弹条失效和扣件系统失效两种失效模式,对车辆运行安全性、平稳性及车辆-轨道相互作用进行分析和评价。结果表明:各评价指标均随着扣件失效个数的增加而增大,5个扣件系统失效时的最大轮重减载率超过规范限值,但未危及车辆运行安全;车辆运行平稳性受扣件失效个数影响较小;扣件系统失效对钢轨影响较大,3~5个扣件系统失效时的垂向位移超限。扣件失效通常会使失效区段附近正常扣件的扣压力和钢轨加速度大于其余位置,从而加剧临近扣件系统的损伤。

A dynamic model of W300-1 fastener system with dynamic frequency-dependent characteristics of the railpad and nonlinear elasticity of spring clip was proposed,considering the preload of the spring clip of the fastener system and the viscoelastic properties of the railpad.The vehicle-flexible track coupling dynamic model was established using SIMPACK,to evaluate in succession from zero to five fasteners the effects of the two failure modes including the spring clip failure and fastener system failure on the safety and stability of the vehicle as well as the vechicle-track interaction.The results show that each evaluation index increases as the number of fastener failures increases.The maximum rate of wheel load reduction exceeds the limit of current code when five fastener systems fail,but does not endanger the safety of the vehicle,while the operating stability of the vehicle is less affected by the number of fastener failures.The failure of the fastener system has a greater impact on the rail,and the vertical displacement of the rail the failure of 3 to 5 fastener systems exceeds the limit.Fastener failure usually causes greater preload of the normal fastener and greater acceleration of the rail near the failure areas than those at the other positions,which exacerbates the damage to the adjacent fastener system.