铁道车辆运行安全评判的轮对爬轨脱轨准则

为了掌握车辆爬轨脱轨机理及主要影响因素,分析了轮对的三维空间受力,推导了轮轨横向力和垂向力比值的一般表示式,假设车轮在达到最大轮缘接触角时为脱轨的临界状态,并认为这时轮轨间出现完全摩擦滑动,导出了不考虑轮对摇头角的临界脱轨判别的二维准则与考虑轮对摇头角和轮轨蠕滑率效应的三维脱轨判别准则,给出了轮轴脱轨系数的定义,采用轮轴脱轨系数和轮重减载率进行脱轨的判别。仿真计算结果表明:二维脱轨判别准则与三维准则相比偏于保守;摇头角越小甚至变负,越有利于防止脱轨,摇头角越大,三维准则的临界脱轨曲线越接近于二维准则的;减小轮轨摩擦系数与增大轮缘角均有利于防止脱轨的发生。

Wheelset climb derailment criteria for evaluation of railway vehicle running safety

In order to understand the mechanism and the main factors that cause vehicle climb derailment,the forces exerted on wheelset in 3D space were analyzed,the general ratio formulae of wheel/rail lateral force to vertical force were derived.It was assumed that wheelset reached the critical state of derailment when flange contact occurred,full friction sliding between wheel and rail appeared,2D evaluation derailment criterion of wheelset without considering wheelset yaw angle was derived,and 3D criterion with taking into account wheelset yaw angle and the effect of wheel/rail creepages was given.The concept of wheelset derailment coefficient was defined,and the combination of wheelset derailment coefficient and wheel load reduction rate was utilized to evaluate derailment.Simulation result shows that 2D criterion is more conservative for derailment evaluation compared with 3D criterion;smaller and negative yaw angles can mitigate derailment possibility,the critical derailment curve of 3D criterion tends to the situation of 2D criterion at larger wheelset yaw angles;the reduction of friction coefficient and the increase of flange angle are advantageous for preventing derailment.1 tab,5 figs,13 refs.