Numerical investigation on wheel-turnout rail dynamic interaction excited by wheel diameter difference in high-speed railway

The wheel-rail relationship in turnout is more complicated than that in ordinary track. Profile wear and machining errors of the wheelset cause deviations Of the rolling radius on different wheels. Therefore, wheelsets move to the direction of smaller diameter wheels in search of a new stable state and to change the condition before entering the turnout. Thc main aim of the present work is to examine the wheel-turnout rail dynamic interaction combined with the static contact behaviour. Calculations are performed on a high-speed vehicle CRH2 and the No. 12 turnout of the passenger dedicated line. The wheel-turnout contac! geometric relationship and normal contact behaviour under wheel diameter difference are assessed by the trace principle and finite element method. A high-speed vehicle-turnout coupling dynamic model is established based on SIMPACK software to analyse the wheel-rail dynamic interaction, riding comfort, and wear. Both the wheel diameter amplitudes and distribution patterns are accounted for. The simulation shows that wheel diameter difference can greatly disturb the positions＇ variation of wheel-rail contact points and affect the normal contact behaviour on switch rails by changing the load transition position. The effect of wheel diameter diffierence on wheel-turnout rail dynamic interaction can be divided into three according to its amplitude： when the wheel diameter difference is within 0-1.5 mm, the wheel flange comes into contact with the switch rail in advance, causing a rapidly increased lateral wheel-rail force; when it is within 1.5 2.5 mm, trains are subject to instability under equivalent in-phase wheel diameter difference; when it is larger than 2.5 mm, the continuous flange-switch rail contact helps strengthen the vehicle stability, but increases the wheel-rail wear. It is recommended to control the wheel diameter difference to within 2.5 mm but limit it to 2 mm if it is distributed in-phase.

目的:车轮型面磨耗和加工误差导致轮对两侧车轮的轮径不同。本文旨在探讨不同幅值和分布形式的轮径差对道岔区轮轨接触几何、轮轨法向接触性能和车辆通过道岔动力响应的影响规律,提出保证车辆通过道岔时的安全性和舒适性的轮径差限值。创新点:通过数值仿真,分析轮径差对道岔区轮轨接触性能和轮轨动态相互作用的影响。方法:1.基于迹线法,揭示轮径差对道岔区轮轨接触几何的影响。2.通过建立轮轨接触有限元计算模型,探讨轮径差对轮轨法向接触性能的影响。3.通过建立车辆-道岔耦合动力学模型,综合考虑在不同幅值和分布形式的轮径差激励下,车辆通过道岔的轮轨动态相互作用、运行舒适性和磨耗指数评价指标,提出轮径差限值。结论:1.轮径差加剧了道岔区固有结构不平顺。2.轮径差通过改变轮载过渡位置,对尖轨上的轮轨法向接触性能有较大影响。3.可根据轮径差幅值将轮径差对道岔区轮轨动力响应的影响划分为三个区域:轮径差小于1.5 mm时,轮缘与尖轨提前接触使轮轨横向力快速增大;轮径差在1.5~2.5 mm时,等值同相轮径差使车辆通过道岔失稳;轮径差大于2.5 mm时,轮缘与尖轨的持续接触增强了车辆稳定性,但增加了轮轨磨耗。4.建议将轮径差控制在2.5 mm以内,且应控制同相分布轮径差小于2 mm。