高速列车-桥梁竖向随机振动的时域分析方法

提出时间相关多维有色噪声形式的轨道不平顺激励下列车-桥梁耦合系统协方差响应的时域递推方法。用白噪声滤波法生成轨道不平顺有色噪声过程,在宽频带内识别滤波器参数以同时实现滤波成型和波长截断功能。提出基于高阶Pade近似的累次时滞系统,以实现列车多轮对下轨道不平顺激励的大时滞再现;再结合成型滤波器构造列车下轨道不平顺激励的一致白噪声模型。建立列车-桥梁垂向振动的状态方程,将其与激励模型联立得到一致白噪声激励下的列车-桥梁扩阶状态方程。将方差递推法推广到时变系统,求解列车-桥梁系统的随机振动。分析结果与Monte Carlo模拟法符合良好,表明了方法的正确性。

Time domain method for high speed train-bridge vertical stochastic vibration analysis

A time domain covariance method for the trainbridge vertical stochastic vibration excited by the time-correlated multidimensional nonwhite noise rail irregularity was proposed.The parameter identification of the shape filter producing the nonwhite rail irregularity was carried out in a wide frequency range to realize the shape filtering and the wavelength truncation together.A stepwise time-delay system based on the high order Pade approximation was proposed to simulate the large time-delay excitations under railway trains.The authors combine the shape filter and time-delay system to construct the rail irregularity model with uniform white noise input.The state-space equation of train-bridge vertical vibration was derived,and was integrated with the excitation model to obtain the expanded order train-bridge-excitation state-space equation with uniform white noise disturbance.By extending the recursive covariance method to time-variant system,the covariance response of train-bridgeexcitation system was obtained.Numerical results coincide with the Monte Carlo simulation.This indicats the correctness of the method.