Identification Of Flutter Derivatives And Flutter Analysis Based On The Aeroelastic Full Model Of A Suspension Bridge With PC Slab Stiffening Girder

Flutter is commonly recognized as one of the most dangerous type of vibration which may result in catastrophic collapse of long-span bridges. Flutter derivatives are aerodynamic parameters describing the aerodynamic performance of bridge girders against flutter instability. The traditional approach to identify the flutter derivatives is through the sectional model wind tunnel test or the computational fluid dynamics. In this paper, identification of flutter derivatives of bridges with either the sectional model test or the aeroelastic full bridge model test is carried out. The main study focuses on the following aspects:1) The procedures, advantage and disadvantage, including in the sectional model free-vibration test, the sectional model forced-vibration test, the taut strip model and the full bridge aeroelastic model test are presented.2) The details of the state-space method and Eigensystem Realization Algorithm (ERA) are introduced. Numerical simulation way is adopted to demonstrate the effectiveness of the method and program based on the two-degree-of-freedom system.3) The basic principles of the Random Decrement Technique (RDT) numerical simulation way is employed to prove the reliability of the method and program based on the two-degree-of-freedom system.4) Wind tunnel tests are applied on the thin plate to extract the flutter derivatives based on the ERA and RDT method, and the results are compared to the Theodorsen analytic solution. The agreement insures the feasibility and reliability of the present method.5) The way to design and manufacture the aeroelastic full bridge model, as well as model validation are presented. Sectional model and full bridge aeroelastic model tests in smooth and turbulent wind are carried out to identify flutter derivatives of a real bridge.6) A frequency-based analysis method in finite element model is used to perform the three-dimensional full bridge flutter analyses for a real bridge engineering, with flutter model and flutter onset wind speeds presented.