轮轨系统空间耦合振动行为下的高速列车车轮谐波磨耗机理研究

Wheel harmonic wear directly affects the operation quality and safety of high speed train, and its formation mechanism urgently needs to be revealed. In this project, the relationship among train/track parameters, vibration behavior of wheel/rail system and wheel harmonic wear is established by field data of high-speed wheel harmonic wear to systematically analyze the causes of harmonic wear. Firstly, current situation of wheel harmonic wear of high-speed train and its formation and development with wheel/rail vibration behavior are comprehensively investigated and analyzed. Then, combining multi-subject theory such as vehicle/track coupling dynamics, wheel/rail friction model and numerical calculation method etc, the rigid-flexible coupling high-speed wheel/rail spatial coupling vibration model are constructed, integrating with wheel/rail functional friction model. The influence of vehicle/track parameters to spatial coupling vibration behavior of wheel/rail system is found by this model to establish the relation between train/track parameters and wheel/rail vibration. Finally, the wheel/rail rolling contact characteristics are computed by constructed high-speed wheel/rail rolling contact transient finite element model. So material characteristics and wear index of wheel tread are analyzed with different wheel/rail vibration behavior to reveal the wheel harmonic wear mechanism in vibrator system. The anticipated research results will provide technical support and theoretical guidance to master the causes of high-speed wheel harmonic wear and put forward its prevention measures.

车轮谐波磨耗直接影响高速列车运行品质和安全，迫切需要揭示其形成机理。本项目从高速车轮谐波磨耗现场测试数据出发，建立列车/轨道参数、轮轨系统振动行为和车轮谐波磨耗三者的关联关系，系统分析高速列车车轮谐波磨耗成因。首先，全面调查分析我国高速列车主流车型车轮谐波磨耗现状及其轮轨系统振动行为下的形成发展规律；接着，基于车辆/轨道耦合动力学、轮轨摩擦模型、数值计算方法等多学科理论，集成高速轮轨函数型摩擦模型建立刚柔耦合高速轮轨空间耦合振动模型；由此分析列车/轨道参数的变化对高速轮轨空间耦合振动行为的影响，并建立列车/轨道参数与不同振动行为之间的映射关系；最后，构建高速轮轨滚动接触瞬态有限元模型，分析不同振动行为下的轮轨滚动接触特性和车轮踏面材料特性及磨耗指数的变化规律，从而最终揭示振动行为下高速车轮谐波磨耗机理。预期研究成果将对掌握高速车轮谐波磨耗成因和提出防损措施提供重要的技术支持和理论指导。

截至2019年底，我国高铁里程已突破3.5万公里，服役高速动车组数量3000余组。车轮谐波磨耗是服役高速动车组车轮常见的损伤形式，直接影响列车运行品质和运行安全，迫切需要揭示其形成机理。本项目从高速车轮谐波磨耗现场测试数据出发，建立列车/轨道参数、轮轨系统振动行为和车轮谐波磨耗三者的关联关系，系统分析高速列车车轮谐波磨耗成因。跟踪测试了向莆线服役动车组CRH2A车轮表面状态变化情况，掌握了服役高速列车车轮表面状态时变特性。探讨符合轮轨接触特性分形理论和有限元方法，分析法向接触载荷、摩擦系数、粗糙度、硬度以及运行里程对轮轨接触刚度和接触阻尼的影响。结果表明：法向刚度随着法向载荷、表面硬度、运行里程的增加而逐渐增大；切向刚度与载荷、摩擦系数、表面硬度呈非线性变化，随之增加而增大；法向阻尼随着载荷、摩擦系数、硬度、运行里程增加而增大，但与粗糙度呈负增长关系；轮轨切向接触阻尼随着法向载荷、摩擦系数、表面硬度的增加而逐渐增大，却随着粗糙度的增大先增大后减小。建立基于弹簧-阻尼接触关系的高速轮轨柔柔接触模型，开展涵盖车辆参数、轨道结构参数、轮轨界面状态等不同条件下的高速轮轨滚动接触振动特性研究，在此基础上重点分析了高速轮轨蠕滑力/率等蠕滑特性的影响因素，接触刚度和阻尼均直接影响轮轨接触力的变化，使得轮轨接触几何实时发生变化，导致更易发生轮轨蠕滑现象。最后，采用蠕滑力与蠕滑率乘积定义的磨耗功来计算车轮踏面磨耗分布，接触斑内的纵向蠕滑力因轮对的高频振动而变化较大，引起在整个接触斑内的磨耗功变化不均匀，速度越大，轮对的磨耗量越大，并且磨耗阶数也在变大。接触刚度和接触阻尼的影响通过摩擦系数反应出来，摩擦系数的的增大车轮接触斑内的纵向蠕滑力加大，磨耗功也随之增大，而纵向蠕滑力的变化趋势不变，这表明，对于高速列车列车，摩擦系数的增加并不会影响轮对磨耗阶数的变化。