Dynamic response analysis and comfort evaluation of wind-train-long-span suspension bridge

A long-span suspension bridge is an engineering background investigating how a suspension bridge and a train respond to wind loads in coupling vibration. The three-component coefficient of the bridge is calculated using Fluent software, and the random wind field is simulated using the wavelet analysis method. An analysis model of wind-train-bridge coupling vibration is developed based on structural dynamics principles considering track irregularities and hunting movements, by combining a self-written calculation program with general finite element software, the system's dynamic responses under wind and train loads are studied, and the train's safety and comfort are evaluated. The findings indicate that the numerical simulation results of the three-component force coefficient of the main girder of a long-span steel truss suspension bridge are reasonable in this paper, and the random wind field obtained by the wavelet analysis method accords with the randomness of natural wind. The long-span suspension bridge's natural frequencies are low and highly susceptible to wind loads. The train's running safety and comfort decrease with the increase in wind velocity, and the system's dynamic responses increase with the wind velocity. The influence of wind-induced vibration in bridges is significantly higher than the train's effect. As the train speed increases, the dynamic responses of the system also increase, resulting in a decrease in the train's running safety and comfort, the train's shock actions on the bridge do not have a significant impact. When the wind velocity exceeds 20 m/s, the train's running safety at 300 km/h cannot be ensured, meeting the relevant provisions of "Technical Management Regulations for Railway". It can provide a reference for the operation decision of long-span bridges with similar geometric characteristics in crosswind environments.