轨道不平顺随机过程的数值模拟

轨道不平顺是列车-轨道系统的动力响应的主要影响因素,不平顺样本是列车-轨道系统动力分析模型中不可缺少的参数.根据随机理论原理推导了轨道不平顺谱的空间、时间域的相互转化关系,得到了时域功率谱的表达式.分析了目前广泛应用几种轨道不平顺随机过程的模拟方法的原理及作法,通过对功率谱快速数值算法的分析给出了一种新三角级数模拟方法,该方法与逆傅氏变换法具有等效性,同时也论证了逆傅氏变换方法样本是高斯过程.最后通过实际算例的分析论证了新三角级数法与傅氏逆变换法在简便、合理等方面的优点.

A numerical simulation of the track irregularity stochastic process

The railway track irregularity is a main influential factor to dynamic interaction of train-track,and the stochastic process sample is a indispensable parameter in the dynamic model for analysis of the train-track.According to stochastic theory,the transformed relation of power spectrum density of railway track irregularity between time and space domain and the expression of power spectrum density in time domain are given.The principles and steps of wide-used method for simulation of the train-truck are analyzed.Through the analysis of numerical method about power spectrum density of the railway track irregularity,a new method of trigonometric series is given,the IFFT and the new method is also equivalent.Finally the numerical simulation shows that both the new method and IFFT are more effective.