Study On Flutter Of Senzhen-Nanshan Bridge By CFD Numerical Simulation

With the rapid development of computer technology, and computational fluid dynamics methods(CFD) continue to mature, more and more scholars in the field of wind-resistant using this method to analyze the wind-resistance of bridge. Different from the wind tunnel test, CFD method is more simple and convenient: it is computationally efficient and does not require a lot of manpower and material resources, operation cycle is short , and a variety of designs can be repeated checking before building, so it has become a important researching tools at the moment. In particular, it provide strong pre-authentication information to preliminary design and development prospects are very good. The subject using CFD numerical simulation method to analyze the flutter characteristics of the Shenzhen-Nanshan bridge. This research covers selection of flutter theories, calculating flutter derivatives, calculation of critical flutter velocity, research of aerodynamic interference effects on twin decks bridges and so on.First, this paper based on the theory of Scanlan flutter derivatives method to simulate the flutter characteristics of bridge deck. Then using computational fluid dynamic methods and dynamic grid of Gambit pre-processing software in Fluent software to meshing deck. The used coordinate system is Lagrange-Euler Coordinate System. Governing equation is N-S Momentum Conservation Equation. Discrete method using Finite Volume Method. Turbulence model is Realizable k-εturbulence model. Use PISO numerical method to iterate. After that using time-domain identification method of forced vibration and frequency-domain identification method to processing extracted data, and calculates the flutter derivatives. Using above method to numerical simulate ideal plate. The results show that the method and theoretical solutions are in good agreement.Secondly, using the above numerical simulation method to calculate the flutter derivatives and the critical flutter velocity of single bridge of Shenzhen-Nanshan bridge. Analyze the results, the method provides an effective pre-authentication information to the design of the bridge;Finally, for the special structure of Nanshan bridge, considering the aerodynamic interference between decks of twin bridges: Under the condition of single side of the bridge is rigid and static, calculate the flutter characteristics of the other side of single bridge; At the same time take the same simulation on another piece of the single bridge. Further found that twin bridge has a greater impact on flutter characteristics of the bridge and critical flutter velocity of twin bridges decreased than the single bridge's.