Wind-Induced Buffeting Time-Domain Analysis For Long-Span Combined Highway And Railway Cable-Stayed Bridge

As a result of increasing bridge span, deck flexibility and structure complexity, the problem of wind-induced vibration of long span cable-stayed bridges has become increasingly prominent. In this thesis, buffeting response of a long span cable-stayed bridge is discussed. Generally, there are two methods to analysis the buffeting response, one is called the frequency-domain simulation with concise computation process, yet severely limited applicable range. And the other is the time-domain simulation which could consider the nonlinear effect and acquire much more result information at the cost of increasing the calculating difficulty and the amount of calculating work accordingly. Here the time simulation is employed to investigate the buffeting response.Taking Yangtze River Bridge as an example, which is a combined highway and railway bridge, attention is focused on analyzing its linear time-domain buffeting response including the completed stage, the largest single cantilever stage and the largest double cantilever stage. The major work is shown as follows:(1),In consideration of the characteristic of long span cable-stayed bridge, the 3-dimesional fluctuating wind field of bridge is reasonably simplified. On this condition, the fluctuating wind field is simulated.(2),The software ANSYS is employed to build the finite element of Yangtze River Bridge and calculate its dynamic characters.(3),The static wind response of the bridge is analyzed. On the basis of Scanlan's quasi-steady aerodynamic theory, the buffeting force is transformed into the time-domain form in order to calculate the bridge buffeting response and analysis the internal force and displacement.(4),The self-excited forces are considered in ANSYS by Matrix27. The effect of aerodynamic admittances is approximately described by the plate aerodynamic admittances function proposed by Liepmann. Moreover, the bridge buffeting response analysis also takes other factors into account such as the speed, the wind attack angle and the cable.(5),In allusion to the calculating result, this thesis is aimed at summarize and make some conclusions. The research has certain reference value for the similar problems in engineering...