Flutter analysis of open-truss stiffened suspension bridges using synthesized aerodynamic derivatives

Aerodynamic analysis is of primary consideration in designing long-span bridges. Theoretical models as well as experimental tools have been developed, which resulted in Wind tunnel tests becoming the fundamental design tool.; Recent researches focus on alternative methods to assess the wind response of suspension bridges. These include the computational Fluid Dynamics (CFD) method, which is based on finite element analysis. Theoretically, this method is capable of solving different types of fluid-structure-interaction (FSI) problems.; This research discusses the flutter analysis of open-truss stiffened suspension bridges, with an emphasis on the Second Tacoma Narrows Bridge. The scope is to assess the wind response of the bridge using analytical tools. The approach suggested here is to synthesize the wind derivatives based on previous studies of a similar deck configuration. Then the equation of motion and the synthesized aerodynamic forces are solved to find the critical wind speed.; In order to conduct an aerodynamic analysis, the frequencies and the mode shapes of the bridge should be determined. Therefore, a frequency analysis is conducted using a detailed finite element model. The results are compared with an ambient study of the bridge, and found to be similar and accurate.; The solution procedure and assumptions of the approach are verified using the Golden Gate Bridge flutter analyses, where the experimental aerodynamic coefficients of the bridge are applied in the proposed procedure and compared with the analysis based on the synthesized coefficients. The results of both cases agree with the results in the literature. The analysis procedure is then conducted for the Second Tacoma Narrows Bridge to estimate the critical wind speed is found to be less than the flutter criteria of the bridge.