Research On Theory And Application Of Train-bridge Coupling System Stochastic Vibration

Train-bridge coupling system has large randomness. The common calculation is only aiming at the special sample, and the randomness can not be observed. In the present ph.d thesis, the pseudo excitation method is applied in the stochastic dynamic analysis of train-bridge coupling system. Comparisons with the Monte Carlo simulations show the effectiveness and satisfactory accuracy of the proposed method. The main research works in this thesis are as follows:1. Stochastic dynamic analysis of train-bridge vertical systemPseudo-Excitation Method (PEM) is applied to transform the random surface roughness of the track into the superposition of a series of deterministic pseudo harmonic surface unevenness. Separate iteration is applied in the solution of equation. Numerical examples are given.Comparisons with the Monte Carlo simulations show the effectiveness and satisfactory accuracy of the proposed method. Stochastic vertical analysis has been done on three span simply-supported beam when trains running on it. Stochasic responses of the train-bridge coupling system corresponding different train velocity have been discussed.2. Stochastic dynamic analysis of train-bridge spatial systemThere are 15 DOFs as to the vehicle model. Without regard to the wheel/rail interaction, Pseudo-Excitation Method (PEM) is applied to the spatial stationary random vibration analysis of train-bridge systems subjected to track vertical profile irregularity, track alignment irregularity and track height difference irregularity of left and right rail. Numerical example proves the validity of the method. Stochastic spatial analysis has been done. Random responses have been discussed corresponding to 9 different train velocities.3. Stochastic dynamic analysis of train-bridge spatial system when wheel/rail interaction is consideredWhen wheel/rail interaction is considered, linearization is adopted according to the solution of the creep force and normal force. Pseudo-Excitation Method (PEM) is applied to the study of spatial stationary random vibration. Mean values and standard deviations of the responses have been compared between two spatial models. The effect of speed alteration on train-bridge coupling system has been discussed.