基于虚拟激励法的车桥系统车速影响分析

本文基于虚拟激励法提出列车-桥梁耦合系统的非平稳随机振动分析的新方法,并借此重点分析车速对系统随机振动的影响。列车每节车辆考虑27个自由度,桥梁模型采用空间Euler梁单元,轨道不平顺假设为多点异相位平稳随机激励。根据时变系统的虚拟激励法,推导得到方向、高低和水平三类轨道不平顺作用下车桥系统响应的时变功率谱及标准差,并采用精细积分法进行迭代计算,最后以高斯型随机变量的三倍标准差为误差范围给出系统响应最大值估计。在数值算例中,用时间历程法验证本文方法的正确性和有效性,并重点讨论列车速度的影响。

Influence of Train Speeds on Random Vibration of Train-bridge Systems

The non-stationary random vibration analysis on train-bridge coupled systems is performed with the pseudo-excitation method(PEM),and the influence of train speeds on system random responses are mainly discussed.Each vehicle of the train is described by 27 degrees of freedom,and the bridge deck is modeled as a three-dimensional Euler beam.The lateral,rotational and vertical irregularities of the track are assumed to be multi-point different-phase stationary random excitations.By PEM for the time-variant system,these track irregularities are transformed into a series of deterministic pseudo harmonic excitations.The corresponding pseudo responses are solved by using the precise integration method(PIM) iteratively.Then the time-dependent PSD and standard deviation of interested quantities can be obtained easily.Finally,an estimation method of the maximum value for such system responses is suggested by taking the 3 times standard deviation of the Gaussian random variable as the error range.In the numerical example,the effectiveness and accuracy of the proposed method are justified numerically by the time history method,and the influence of the train speed on system random responses is mainly discussed.