高弹轨道钢轨短波长波磨生成机理及其检测与抑制方法研究

To alleviate the vibration effects caused by passing trains, it is necessary to take measures to reduce or isolate the vibration for urban rail transit route. High elastic fastening it is of good capability in reducing and isolating vibration for it can reduce the dynamic force between the rail and wheel as well as the force transmission to road bed, and so now the simple and easy measure has been widely adopted. However, serious corrugation has been often observed in the rail equipped with high elastic fastening, which can increase the dynamic force between the rail and wheel and, consequently, lead to strong vibration and noise. According to the current theory and knowledge, the high stiffness fastening could raise corrugation to straight line railway. On the contrary, the high elastic fastening could suppress the corrugation appearance. Obviously, the existing theory cannot explain the presence of corrugation in the rail of high elastic fastening. In this project, the coupling dynamics between multiple wheels and high elastic rail will be investigated to reveal the mechanism governing the appearance of short pitch corrugation and, further, to develop effective method to suppress the corrugation appearance. The final objective is to achieve both the vibration isolation and absence of corrugation. In addition, the effect of corrugation to the vibration of the railcar and its key components will be studied. Furthermore, novel method will be developed for corrugation measurement. It is hopeful that the outcomes of the project will offer theoretical foundation and key technique support for comprehensive measure of rail corrugation so as to further improve the international leading status of our country in the railway transportation field.

城市轨道交通线路需要在敏感地段采取减振隔振措施，减少列车运行引起的振动对环境的影响。高弹性扣件通过降低轮轨动态力及其向道床的传递起到隔振和减振作用，因其简单易行而得到广泛应用。但近年来发现采用高弹性扣件的轨道存在严重的钢轨波磨现象，使得轮轨动载荷、振动和噪声增加，导致其应用受限。国内外现有研究结果认为，直线段钢轨波磨可发生在大刚度扣件轨道，高弹性扣件轨道不会发生钢轨波磨，采用高弹性扣件反而可以抑制波磨。现有理论不能解释目前的现象。本项目从研究多车轮与弹性轨道耦合动力学着手，阐明高弹性轨道的短波长波磨现象产生机理，发展有效的钢轨波磨抑制方法，达到采用高弹性扣件既能隔振，又不会发生钢轨波磨的目的；明晰钢轨波磨对车辆及其关键构架的振动响应的影响，发展基于振动响应分析的波磨检测方法和和装置。为我国轨道波磨顽疾的综合治理提供理论依据和关键技术支持，进一步提高我国轨道交通业的国际领先地位。

轨道交通的快速发展从根本上扭转了长期困扰社会的出行难状况，与此同时也带来了环境振动与噪声问题。轮轨作用下钢轨产生的波浪形磨耗是轨道交通振动噪声问题的源头。钢轨波磨是轮轨动力学、滚动接触、蠕滑和磨损等多种因素综合作用的复杂结果，国内外对波磨形成机理研究已有几十年历史，但一些研究结果与实际不符。主要原因是多方面的：首先，实验室试验很难模拟轮轨动力学和滚动接触蠕滑磨损的实际情形，也不可能通过现场测试来了解轮轨接触区动态应力、蠕滑和磨损的真实情况；另外，波磨的发生和形成是正反馈过程，理论研究中只要某个因素能构成正反馈回路，似乎就能得到波磨形成的机理。但这种似是而非的结果多数与实际不符，只能算作猜想。虽可发表论文，却无应用价值。. 本项目立足于轨道交通工程实际，结合理论分析和仿真计算，对钢轨短波长波磨形成机理开展研究；在探明波磨形成机理的基础上，找到既可以降低钢轨振动与噪声，又能够抑制钢轨波磨进展的技术措施。本项目研究结果表明，高弹性轨道的阻尼比较小，振动波在钢轨中传播衰减较慢，车轮之间的反射波较强，从而形成较强的驻波；这种驻波导致轮轨动态力在一些频率出现峰值，并且在某个峰值频率轮轨力与波磨的相位匹配，可使钢轨的不均匀周期性磨耗发展成为特定波长的钢轨波磨。项目研究依据钢轨波磨形成机理，研发了新型调谐式钢轨阻尼器，安装于高弹性轨道，既有降低波磨引起的轮轨振动与噪声的即时效果，又有抑制波磨发展、减小已有钢轨波磨程度的长期效果。项目研究成果已在国际刊物发表多篇SCI论文，并在城市轨道交通工程实际中得到应用和验证，具有推广应用前景和价值。