Study On Three-Dimensional Flutter Analysis In Frequency-Domain Of Suspension Bridges And Their Flutter Stability When Erection

Flutter has a critical bearing on the design of suspension bridges that in the rising tide in China. The three-dimensional flutter analysis in frequency-domain of suspension bridges and theirs flutter stability when construction is carried out in terms of dealing with the project of constructing a suspension bridge桳ancang Jiang bridge, besides with other engineering projects.At first, the non-linear influcence factors are analysed in the present paper. Based on finite dispacement theory, and with the help of finite element software ANSYS, the static and dynamic characteristics of the bridge is analysed. Based on the flutter equations and the PK~F method, the three-dimensional flutter program is compiled with MATLAB software. With the program, two actual examples are calculated and the results prove the PK-F method is exact and feasible. And if the long-span suspension bridge were only analysed by the two-dimensional flutter analysis, the results would perhaps be unsafe. At last, with two actual engineerying projects, the static and dynamic characters and the flutter critical wind speed of the two suspension bridge during the erection stage are calculated by use this program. Furthermore, the flutter stability influenced by the difference torsion stiffness and structural damp of the main girder is discussed. The long-span suspension bridge' s and the middle-span bridge' s flutter stability are compared when erection. And if the flutter is controlled by dissymmetrial mode, the fact of critical wind speed of flutter can be improved effectively by installing the middle-buckle is proved.