随机风速下高速列车的运行安全可靠性

OPERATIONAL SAFETY RELIABILITY OF HIGH-SPEED TRAINS UNDER STOCHASTIC WINDS

基于可靠性理论提出了随机风速作用下高速列车风致安全分析的新方法,这种方法可以对随机风速作用下高速列车的运行安全可靠性进行有效评估.首先基于Cooper理论和谐波叠加法计算随车移动点的脉动风速,建立随机风速作用下高速列车非定常气动载荷的计算方法,并通过数值仿真得到气动载荷系数的标准差随侧偏角的变化规律.然后建立高速列车车辆系统动力学模型,并对计算模型的正确性进行验证.最后以随机风速、侧力系数、升力系数、侧滚力矩系数、摇头力矩系数和点头力矩系数为基本随机变量,研究随机风速作用下高速列车的运行安全可靠性和可靠性灵敏度,给出随机风速作用下高速列车的概率特征风速曲线.研究结果表明:随着车速和风速的增大,系统的失效概率增大;通过可靠性灵敏度分析发现侧力系数和侧滚力矩系数对高速列车的运行安全影响最大,应该特别注意这两个参数的变化对高速列车运行安全性的影响;传统确定性方法得到的高速列车的安全域曲线偏于保守,基于可靠性的方法可得到更合理的安全域曲线.

A new method of analyzing the crosswind stability of high-speed trains is proposed based on reliability theory,which can be the effective assessment of operational safety reliability of high-speed trains under stochastic crosswinds.Firstly,the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based on Cooper theory and harmonic superposition method,and the method of the unsteady aerodynamic loads of high-speed trains under stochastic crosswind winds are presented.The standard deviation of the aerodynamic load coeffcients varying with the slip angles are obtained by numerical simulation.Then the vehicle system dynamics model of high-speed trains is established,and the result computed by the model in this paper is compared with the test data to verify the correctness of the model.Finally,the stochastic winds,side fore coeffcient,lift force coeffcient,roll moment coeffcient,yaw moment coeffcient and pitch moment coeffcient are dealt with as basic random variables,and the operational safety reliability and reliability sensitivity of high-speed trains under stochastic winds are calculated in this paper.This finally leads to the probabilistic characteristic wind curve.The results show that,the probability of failure increases as the vehicle speed or wind speed increases.The side force coeffcient and roll moment coeffcient cause the greatest impact on the operational safety of high-speed trains.Thus,when assessing the crosswind stability of high-speed trains,special attention should be paid to the variation of these two parameters.The operational safety domain computed by the traditional deterministic method is too conservative,and a more reasonable safety domain curve can be obtained using the method based on the reliability theory.