Aerodynamic Interference Effect Analysis Of A Long-span Bridge

The aerodynamic aeroelastic instability mechanism of a large span cable-stayed suspension bridge was studied. Based on the self-excited aerodynamic force theory of Scanlan, the Finite Volume Methed was used to analysis the streamlined and blunt cross section bridge, by using the software embedded in Fluent self UDF program. Vortex-induced maximum responses of the whole bridge were calculated by modal analysis with Ansys program. The main contents are mainly as the follows:1.The aerostatic coefficients of streamline and blunt cross section bridges with staticwinds and fluctuating wind were analyzed, based on the turbulent flow equations. The influence of angle of the flow field of a blunt cross section bridge was analyzed.2. Based on the Scanlan self-exciting force theory, part-condition forced oscillation and Fluent program, the aerostatic were identified. The flutter derivatives of the blunt and streamline cross section bridge were identified by using the least squares method, and the frequencies and the critical wind velocities of flutter of the bridge were calculated.3. Vibration characteristics of a whole bridge was analyzed by using Ansys program. The critical velocity of wind and allowable amplitude of vortex induced vibration of bridge was estimated with the empirical formula in specification for Highway Bridges.