【摘要】 列车随机荷载数定是进一步研究地铁运行下环境响应的先决条件,列车随机荷载数定的精确与否直接影响下一步环境响应的分析结果.前人的做法通常是将现场实测的轨道加速度视为各态历经的高斯平稳随机过程,由一系列谐波的叠加组成.通过建立列车-轨道模型,将实测加速度作为激励信号输入,确定频域响应函数,借助于快速傅里叶变换算法,最终得到作为响应的列车随机荷载.这种方法的局限性在于由于变换在频域中进行叠加,要求系统必须是线性的.为此,通过在Matlab中编程,实现用时域逐步积分的Newmark-β法模拟列车随机荷载,可以同时适用于线性和非线性系统,具有更广的实用性.更多还原

【Abstract】 It is the prerequisite for the further study of the enviroment response under random train load as identifying the random train load and the precise of train load affect directly the result of the next step. It is usually took in-situ measured accelaration as a gaussian stationary ergodic random process,composed by the superposition of a series of harmonics. Acorrding to the establishment of the train-track model and input the in-situ measured accelaration,the frequency response function is determined. By means of fast fourier transform algorithm,the response of random load of train was determined. But the limitation of this approach is due to superposition in the frequency domain and demanding a linear system. So it is more available to identify the random load of train directly in time domain by the Nemark-β method with programming in Matlab.更多还原