Research on Vertical Resonance Response of Bridge in Train-bridge Interactive System Based on Pseudo Excitation Method

Track irregularity is a common random excitation in train-bridge interactive system, which randomizes the bridge resonance response under the joint effect of train moving axle load. Hence, determination of the possibility distribution of bridge resonance response is important to ensure the safety. For the purpose of overcoming the uncertainty and the inefficiency, respectively caused by single-sample track irregularity in spatial domain and by multiple samples calculation, the space state equation of two-dimensional train-bridge interactive system was formulated by using pseudo excitation random vibration analysis method. Considering the random excitation of track irregularity and deterministic axle load excitation, under the condition of the train running at different constant speeds, the precise integral method was adopted to solve the equation efficiently and accurately through the inter-system iteration process. The results were compared with those of the Newmark-p method under the Monte Carlo sampling, which helps to determine the possibility distribution model fit for the vertical response of bridge. Finally, the time-frequency response of the bridge was analyzed when the vertical resonance occurred, which helps to guarantee the safety when the train crosses the bridge. © 2023 Science Press. All rights reserved.