兰新客运专线动车组车轮多边形磨耗的机理

由于兰新客运专线的线路复杂环境，动车组车轮多边形磨耗现象严峻，加大了列车运行过程中的轮轨作用力，影响了乘客舒适性，给高速列车的安全运行造成极大威胁. 为解决上述问题，基于长期跟踪客运专线获得的车轮多边形磨耗规律以及摩擦自激理论的观点，建立了轮对-钢轨-轨道板摩擦耦合自激振动模型，通过复特征值分析方法来研究车轮多边形磨耗的形成原因及其发展规律. 研究结果表明，在直线线路上，轮轨间蠕滑力饱和引起的摩擦自激振动易导致车轮第15～16阶多边形磨耗；在制动系统和轮轨系统耦合的情况下，动力轮对和非动力轮对对应的不稳定振动频率分别容易引起第23～24阶和第22～23阶车轮多边形磨耗；轮轨之间的黏着系数变大可能是导致冬春季车轮多边形发展速度较夏季快的重要原因. 

Mechanism of Polygonal Wear on Wheels of Electric Multiple Units on Lanzhou-Xinjiang Passenger Dedicated Line

Wheels of the electric multiple units (EMU) running on the Lanzhou-Xinjiang Passenger Dedicated Line have undergone severe polygonal wear because of the harsh environment. This wear increases the contact force between wheels and rails, affects the comfort of passengers, and even endangers train running. To deal with it, the models of the coupled friction and self-excited vibration for a wheelset-track-slab system are established on the basis of the wheel polygonal wear rules obtained by the long-term tracking and the frictional self-excited vibration principles. Then, the cause and development pattern of the wheel polygonal wear are studied by using the complex eigenvalue method. The results show that the frictional self-excited vibration caused by the saturated creep force between wheels and rails can easily result in the 15th?16th order polygonal wear on a straight line. Meanwhile, when the braking system is coupled with the wheelset-track system, at the unstable vibration frequencies of the power wheelset and un-power wheelset, the 23th?24th and 22th?23th order polygonal wear emerges. Finally, the increasing adhesion coefficient between the wheels and rails may account for the fact that the wheel polygonal wear develops faster in winter and spring than in summer.