Study On Areodynamic Admittance Function Of Truss Girder Based On High Frequence Force Balance Test

As the span length of bridges increasing, Bridge buffeting response caused by atmosphere turbulence cannot be ingnored, further study the Buffeting theory is very important to accurately predict buffeting response and seek relevant measures of vibration elimination. Identifing accurately aerodynamic admittance is a key breakthrough to get exact buffeting response, and the wind tunnel test is a main means to identify aerodynamic admittance function at present. Aerodynamic admittance of box section girders, which widely used in long span bridges, has more mature conclusions since most scholars do relevant research. But for the aerodynamic admittance of truss section has seldom research conclusions, and the manometric method which used in identifying aerodynamic admittance of box section is not suitable to truss section. In view of this limitation, contents of this paper as follows:(1) Introduce research status and concrete research method of long span bridge buffeting response, and introduce research status of the aerodynamic admittance. Moreover, paper points out the importance of further studying the aerodynamic admittance to accurately analyze the buffeting response.(2) From atmosphere turbulence properties and section aerodynamic response these two aspects to state key factors of bridge buffeting response analysis. On the one hand, paper highlight atmosphere turbulence properties and wind tunnel test technology of atmosphere turbulence. On the other hand, according to aerodynamic response feature of structure section in turbulence wind field, introduce the aerodynamic admittance recognition theory and wind test method to recognize the Aerodynamic admittance.(3) A experimental study about aerodynamic admittance of truss section in wind tunnel was did. To discuss feature size change, wind attack angle change influence on aerodynamic admittance, we design three different scale ratio model and use the High Frequence Force Balance force test to research the aerodynamic admittance. Then through numerical simulation technology to obtain expirical formula of The aerodynaminc admittance. At last, use expirical formula to analyze buffeting response of a long span bridge, and then verify the correctness and reliability of aerodynamic admittance of truss section.