高速车辆动态脱轨临界状态评判方法

针对传统准静态脱轨系数指标监测高速车辆动态脱轨安全性时的局限性,提出基于车轮抬升量和轮对横移量、以轮对运动姿态决定的脱轨临界状态判断准则;建立高速车辆多刚体动力学模型,分析高速车辆动态脱轨非线性动力学特性,研究轮对运动姿态与车辆振动响应变化规律之间的关系,表明轮对横向振动加速度与车轮抬升量规律较一致;运用高速车辆动态脱轨评判方法进行评判时,首先采用轮对横向振动加速度移动均方根值作为评判车辆脱轨的指标,然后确定该指标能有效反映车轮抬升量变化时的滤波频率范围和滤波时间窗宽,最后确定该指标的合理限值。算例验证表明:该评判方法可有效监测动态脱轨安全性;轮对横向振动加速度移动均方根统计波形与车轮抬升量的变化趋势具有很高的同步性,不仅可以间接地反映轮对运动姿态的变化及车轮抬升的高度,还可以克服轮轨垂向力为零时脱轨系数失真的缺点,在评判高频动态脱轨时的可靠性更高。

Critical State Evaluation Method for Dynamic Derailment of High Speed Vehicle

In view of the limitation of the traditional quasi-static derailment coefficient index in monitoring the dynamic derailment safety of high-speed vehicles,this paper proposes a judgment criterion for derailment critical state based on the wheel vertical rise and the wheelset lateral displacement,which is determined by the wheelset motion gesture.A multi-body dynamic model of high-speed vehicle is established to analyze the nonlinear dynamic characteristics of high-speed vehicle dynamic derailment.The relationship between wheelset motion gesture and vehicle dynamic response is investigated,and the results show that the wheelset lateral acceleration is in good agreement with the wheel vertical rise.When using the proposed dynamic evaluation criteria for the dynamic derailment of high-speed vehicles,the root mean square value of the wheelset lateral acceleration is first used as an index to evaluate the derailment of vehicles.Then the filter frequency range and filter time window width when the index can effectively reflect the change of wheel vertical rise should be determined.Finally,the reasonable limit value of the index is determined.Numerical simulation results show that the evaluation criteria can effectively monitor the dynamic derailment safety.The statistical waveform of the root mean square value of the wheelset lateral acceleration almost has the same trend with the wheel vertical rise.The new index can not only indirectly reflect the change of wheelset motion gesture and the wheel vertical rise,but also overcome the defect of the derailment coefficient distortion when the wheel-rail vertical force is zero,thus it is more reliable in evaluating the high-frequency dynamic derailment.