车辆系统空气弹簧失气安全性分析

建立了具有刚度衰变特性的空气弹簧失气模型和非线性粘滑接触模型,结合车辆系统动力学,模拟空气弹簧失气动态过程与失气后的应急状态,分析了空气弹簧失气后车辆系统的稳定性与空气弹簧突然失气对车辆动力学性能的影响,研究了不同失气过程时长、运行速度与曲线通过工况下空气弹簧失气车辆的安全性。计算结果表明:空气弹簧失气后车辆临界速度由623km.h-1大幅降低为351km.h-1。空气弹簧突然失气导致轮轨垂向力减小,轮重减载率增大,且失气过程越短,轮重减载率越大,失气过程为0.2s时轮重减载率达到0.651。车辆运行速度低于300km.h-1时,车速对轮重减载率和轮轨力影响不明显,当大于300km.h-1时,减载率随车速增大迅速增大。车辆通过曲线时,在圆曲线上失气最危险,轮重减载率最大为0.652。

Safety analysis of railway vehicle in leakage process of air spring

The leakage model of air spring with stiffness decay characteristics and the nonlinear stick-slip contact model were established.The dynamic process in loss of gas and the state of emergency after loss of gas were simulated by combining the two models with vehicle system dynamics.The stability of vehicle system with air spring failure was analyzed.The impact of air spring’s sudden leakage on the dynamics performance of vehicle was simulated.The running safeties of vehicle under different times of loss of gas,different speeds and curve negotiation conditions were studied.Analysis result shows that the critical speed of vehicle system with air spring failure significantly decreases from 623 km·h-1 to 351 km·h-1.Because of air spring’s sudden leakage,wheel-rail vertical force decreases and reduction rate of wheel load increases.The shorter the leakage process is,the greater reduction rate of wheel load is.It reaches 0.651 when the leakage time is 0.2 s.The influence of speed on reduction rate of wheel load and wheel-rail force is not obvious when vehicle speed is less than 300 km·h-1.But,when it is greater than 300 km·h-1,reduction rate of wheel load increases rapidly with speed increase.Leakage occuring on circular curve is most dangerous when vehicle runs,and the maximum of reduction rate of wheel load is 0.652.2 tabs,12 figs,15 refs.