Spectral Distribution of Derailment Coefficient in Non-Linear Model of Railway Vehicle–Track System With Random Track Irregularities
Spectral Distribution of Derailment Coefficient in Non-Linear Model of Railway Vehicle–Track System With Random Track Irregularities
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DOI：
10.1115/1.4023352
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发表时间：
2013-07
影响因子：
2
通讯作者：
E. Kardas-Cinal
中科院分区：
文献类型：
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作者：
E. Kardas-Cinal
提高运行安全性、降低脱轨风险是铁路车辆运行特性评价的重要目标。目前关于防脱轨安全性的研究主要集中在轮对蛇行对脱轨系数的影响，特别是在功率谱密度（PSD）中的反映。通过对四轴轨道车辆在具有随机几何不平顺的直线轨道上沿着匀速运动的数值模拟，得到了轮轨接触处的横向Y力和垂向Q力。的PSD，计算作为空间频率的函数，被发现有一个特征结构，具有三个峰值的前，后转向架的前轮对和一个峰值的后轮对。PSD最大值的位置随着行驶速度的增加而保持不变，而它们的幅度和形状会发生变化。所有轮对的PSD峰值之一出现在与轮对蛇行相对应的相同空间频率处，而前导轮对的PSD峰值出现在双蛇行频率处。这种峰值结构也被发现在PSD中确定的车辆一系悬挂的修改参数的仿真和不同的轨道区段。通过对接触力、轮缘角及其PSD的详细分析，表明双蛇行频率处的峰值是由于轮轨接触的非线性几何形状导致的二次谐波项。该峰值的出现还与轮对横向位移的蛇行振荡与其横摆角振荡之间的相位差密切相关，对于该相位差，前导轮对明显小于尾随轮对。最后，轮对蛇行的影响也表现在运行平均值的强烈依赖性，这是用于铁路技术安全标准的安全性评估对脱轨（与纳达尔标准），对应用的窗口宽度。
Improving the running safety and reducing the risk of derailments are the key objectives in the assessment of the running characteristics of railway vehicles. The present study of the safety against derailment is focused on the effect of wheelset hunting on the derailment coefficientand, especially, how it is reflected in the power spectral density (PSD) of. The lateral Y and vertical Q forces at the wheel/rail contact are obtained in numerical simulations for a four-axle railway vehicle moving at a constant velocity along a tangent track with random geometrical irregularities. The PSD of, calculated as a function of spatial frequency, is found to have a characteristic structure with three peaks for the leading wheelsets and one peak for the trailing wheelsets of the front and rear bogies. The positions of the PSD maxima remain unchanged with increasing ride velocity, while their magnitudes and shapes evolve. One of the PSD peaks occurs for all wheelsets at the same spatial frequency corresponding to the wheelset hunting, while an additional peak at the double hunting frequency is found for the leading wheelsets. Such a peak structure is also found in the PSD ofdetermined in simulations with modified parameters of the vehicle primary suspension and for different track sections. The peak at the double hunting frequency is shown, by a detailed analysis of the contact forces, the flange angles and their PSDs, to result from the nonlinear geometry of the wheel/rail contact leading to the second-harmonic term in. The emergence of this peak is also closely related to the phase difference between the hunting oscillations of the wheelset lateral displacement and the oscillations of its yaw angle, for which the difference is significantly smaller for the leading wheelset than for the trailing one. Finally, the effect of wheelset hunting is also shown to manifest itself in the strong dependence of the running average of, which is used in the railway technical safety standards for the assessment of the safety against derailment (with the Nadal criterion), on the applied window width.