Research On Aerodynamic Characteristics And Coupled Vibration Of Train-Bridge System Under Crosswind Condition

With the continuous development of transportation industry in our country, the train speed keeps constantly increasing, as well as the bridge span. But for long-span bridge, which has huge span but relatively low stiffness, is usually located in the rivers and straits under strong wind. Therefore, coupled vibration problems stand out when the train passing the bridge in a high speed, and security and stability of the train is difficult to be guaranteed at the same time. So, it is necessary to study the coupled vibration problem of train-bridge system in crosswind environment.The coupled vibration problem of road-rail steel truss girder cable-stayed bridge of Lian island in Pingtan strait is taken as the main issue in this paper, air dynamics and multibody dynamics simulation model of train-bridge system is established. Also, the flow field characteristics, the aerodynamic load, train and bridge coupled vibration response are studied in different speed of the wind and the train. In this paper, the main research contents include:1) The basic theory of aerodynamics and multi-body dynamics were introduced, as well as the modeling method of air dynamics and multibody dynamics model of the train-bridge system.2) The air dynamics simulation model of train-bridge system was established by the method of Local dynamic layer grid and computational fluid dynamics software---FLUENT. And the changing rules of the flow field characteristics and the aerodynamic load were analyzed in the condition of single driving and double passing, different wind speed and train speed were considered at the same time.3) The three-dimensional space model of train-bridge system was built through ANS YS and SIMPACK, applying aerodynamic load in the time excitation way to calculate the dynamic response of train-bridge coupled system under the influence of crosswind.4) The changing rules of dynamic indicators of train and bridge were investigated, considering the effect of different wind and train speed, the single and bidirectional passing. Also, the safety and comfort of the train was assessed in the process of running, based on the train and bridge evaluation standard, and presented a single line and double line driving speed and wind speed limit.