摘要
随着重载货物运输的快速发展,重载铁路逐渐暴露出诸多问题,轮轨界面损伤问题日益加剧,这对重载铁路的正常服役和列车运行安全带来了严峻的挑战。为解决大轴重荷载作用下的轮轨滑动引起的摩擦热损伤问题,采用半赫兹理论求解重载轮轨接触行为,借助半无限空间热传导理论描述轮轨滑动过程中的热传递过程,并考虑大蠕滑条件下的轮轨切向作用,系统地建立移动轴荷载下的轮轨热-力耦合模型。钢轨的摩擦热损伤程度以轮轨滑动过程中的钢轨表面相变引起的硬化深度来表征和量化。在该模型的基础上,研究重载轮轨非赫兹接触行为,分析钢轨硬化深度随车辆轴重和运行速度变化的基本特征,探明大蠕滑率条件下钢轨型面、轨底坡和摩擦状态等对钢轨硬化深度的影响规律。研究结果表明:大轴重荷载作用下半赫兹轮轨接触理论可更为准确地描述非椭圆轮轨接触行为;大蠕滑率条件下钢轨表面不可避免地产生材质硬化现象,且在车辆低速滑动时更为显著;增大车辆轴重会明显加剧钢轨热损伤程度。另外,采用CN60轨而非CN75轨时,钢轨的热损伤程度有所降低;选择CN75轨配合1:20轨底坡则可有效缓解钢轨的热损伤;钢轨表面润滑对钢轨热损伤的控制也起到一定的积极作用。
With the rapid development of heavy-haul freight transportation, many problems have emerged, and the damage of wheel-rail interface has become increasingly severe. Such issues bring severe challenges to the normal service of heavy-haul railway and the safety of train operation. In order to resolve the problem of wheelrail frictional thermal damage under the moving heavy axle load, a wheel-rail thermology-mechanics coupled model was established systematically. It included the semi-Hertzian method for the determination of the wheelrail contact patch, the heat conduction theory in the semi-infinite space for describing the heat transfer process during wheel/rail sliding and the wheel-rail tangential model under large creepages. The degree of thermal damage of rails was characterized and quantified by the rail hardening depth caused by the phase transition of the rail material. Based on this model, the non-Hertzian contact behavior of the heavy-haul wheel-rail was studied and the thermal damage characteristics of rails was analyzed in the cases of different axle loads and running speeds. The influences of rail profile, rail cant and friction state on the thermal damage of rails under large creepages were also explored. The results show that the semi-Hertzian theory can describe the non-elliptic wheelrail contact behavior more accurately under large axle loads, whereas the rail surface inevitably exhibits the problem of the material hardening under the condition of large creepages, which is more obvious at a lower running speed. The thermal damage of rails is obviously aggravated with the increase of the axle load. The damage level of the CN60 rail is less than that of the CN75 rail, while CN75 rail with the rail cant of 1:20 can effectively alleviate the rail thermal damage. In addition, the lubrication has a positive effect on the control of the rail thermal damage.
作者
徐培娟
张大伟
田抑阳
钟琛
XU Peijuan;ZHANG Dawei;TIAN Yiyang;ZHONG Chen(School of Transportation Engineering,Chang’an University,Xi’an 710064,China;School of Automobile,Chang’an University,Xi’an 710064,China;State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China;Chongqing Rail Transit(group)Co.,Ltd.,Chongqing 401120,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2021年第12期3155-3163,共9页
Journal of Railway Science and Engineering
基金
国家自然科学基金青年科学基金资助项目(71801019)
陕西省自然科学基金资助项目(2020JQ-342,2020JQ-363)
牵引动力国家重点实验室开放课题资助项目(TPL2108)
中国博士后科学基金资助项目(2021M693752)。
关键词
重载
钢轨
半赫兹
热传导
硬化深度
heavy-haul
rail
semi-Hertzian method
heat conduction theory
hardening depth
