SIMPLIFIED CFD MODAL AND AERODYNAMIC CHARACTERISTICS OF INVERTED TRAPEZOIDAL PLATE-TRUSS DECK

With its good properties of integrity and reasonable mechanics, the plate-truss deck is gradually widely used in the construction of railway bridges. But its wind-resistant capability becomes one of the important factors controlling the bridge design with the increasing of a bridge span. A simplified CFD modal was presented by the basis of the equivalent trusses area acted by wind. The modal fully consider the aerodynamic interference between the structural members at windward and leeward sides. The modal neglects the aerodynamic interference at the junction of top chords, bottom chords and web members. The three-dimensional plate-truss deck is simplified into a two-dimensional cross section, which can reduce the modeling difficulty and calculation work. The static aerodynamic coefficients, vortex-vibration performance and flutter derivatives of the inverted trapezoidal plate-truss deck are simulated. The influence of train existing on the deck is investigated. The research results show that vortex vibration performance of the inverted trapezoidal plate-truss deck is more sensitive to the Reynolds number, and the existence of the train can significantly changes the aerodynamic characteristics of the plate-truss deck.