基于轮轨多点接触的浮置板轨道钢轨波磨安全限值分析

Analysis on limiting value of rail corrugation of floating-slab track based on wheel/rail multi-point contact

地铁线路中钢轨产生的波磨,会使轮轨相互作用恶化,危害车辆及轨道的使用寿命,进而导致养护工作量和维修费用的增加,甚至影响列车运行安全性.确定钢轨波磨安全限值并及时打磨是消除钢轨波磨危害的有效手段.为了确定浮置板轨道钢轨波磨安全限值,基于车辆-轨道耦合动力学理论建立车辆-浮置板轨道耦合动力学模型分析钢轨波磨对车辆-轨道耦合系统的动力学影响,并从车辆运行安全性、运行平稳性和车-轨动态作用性能3个方面考量,提出地铁浮置板轨道线路钢轨波磨的限值.为了更准确地描述轮轨相互作用,所建立的车辆-浮置板轨道耦合动力学模型采用了改进的Kik-Piotrowski方法以考虑轮轨多点非Hertiz接触.研究结果表明,钢轨波磨的出现会使得轮轨相互作用明显恶化,特别是波长小于75 mm的钢轨磨耗;随着钢轨波磨的波长减小、波深加大,轮轨垂向力、轮轨横向力以及脱轨系数、轮重减载率等评价指标都呈现恶化的趋势;其中轮重减载率受波长波深的影响最明显,在一定波长下,随着波深的增加,轮重减载率也最先超出安全限值.当列车运行速度为80 km/h时,波长为0.05 m左右的钢轨波磨的波深应控制在0.2 mm以下,波深为0.1 mm左右的钢轨波磨的波长应控制在30 mm以上.

In the metro railway,the rail corrugation will aggravate the dynamic wheel/rail interaction,reduce the service life of the components of the vehicle and the track,increase the cost of maintenance and workload,and even threaten the vehicle running safety.It is an effective method for eliminating the adverse effects of rail corrugation to determine the limiting value of rail corrugation and grind the rail without delay.In order to determine the limiting value of rail corrugation for floating-slab track(FST),the vehicle-FST coupled dynamic model is developed,based on the vehicle-track coupled dynamics theory,to analyze the influences of rail corrugation of different levels on the dynamic responses of vehicle-track coupled system.Then the limiting value of rail corrugation is proposed from the aspects of the vehicle running safety,the vehicle running comfort and the dynamic performance of vehicle-track coupled system.In the model,the vehicle is treated as multi-rigid-body system of 35 degrees of freedom and the suspension systems are modelled by linear or nonlinear spring-damper elements.The rails are simplified as Euler beams.The vertical motions of the floating slabs are described by elastic thin plate,and for the lateral motions and rotations in the horizontal plane,the slabs are treated as rigid bodies.The mechanical behaviors of the fasteners and steel spring are described by linear spring-damper elements.In order to more accurately descript the wheel/rail interaction,the improved Kik-Piotrowski method is used in the vehicle-FST coupled dynamic model to consider the wheel/rail multi-point non-hertz contact.The results show that,the rail corrugation will observably aggravate the dynamic wheel/rail interaction,especially in the case that the wave length of the rail corrugation is below 70 mm.With the wave length of the rail corrugation decreasing or the wave depth of the rail corrugation increasing,all of the vertical wheel/rail forces,the lateral wheel/rail forces,the derailment coefficient and the reduction ratio of wheel load are worsened.The influences of the wave length and wave depth of the rail corrugation changing on the reduction ratio of wheel load is the most obvious.When the wave length of the rail corrugation is constant and the wave depth is creased,the reduction ratio of wheel load will exceed the safety limit before the other indicators over the limits.In the case that the train is running with the speed of 80 km/h,when the wave length of the rail corrugation reaches about 0.05 m,its wave depth should be controlled to be below 0.2 mm.Besides,when the wave depth of the rail corrugation reaches about 0.1 mm,its wave length should be controlled to be more than 30 mm.