关键词: 抖振力, 气动导纳, 互功率谱法, 扁平双边肋主梁, 频谱

Abstract: On the basis of simulation of structure of Jingsha River Yangtze Bridge, the aerodynamic admittances are studied by means of cross-correlation spectrum recognition with data gotten from segmental modeling＇s dynamometer wind-tunnel experiment in turbulence flow. Through comparison with traditional method, it is found that aerodynamic admittances gotten by cross-correlation spectrum recognition are less than traditional ones and Sears function on quantity in general, although both results had the same trend of change with the rise of reduced frequency. The buffeting force is calculated through complex aerodynamic admittances, and the spectrum analysis is also carried out. Comparing with those data measured from experiments, it is found that both of them have the same trend of change with the rise of reduced frequency, although they have certain differences in quantity. Through the comparison of buffeting force spectra in different turbulence flow, whose turbulence intensity are 6%, 10%, 20% respectively, with the consideration of different wind attack angle ranging from -5°to ＋ 5°, it is found that the difference of quantity between results calculated by complex aerodynamic admittances and those measured from experiments are steady and almost independent on the change of wind attack angle and turbulence intensity.

Key words: buffeting force , aerodynamic admittance , cross-correlation spectrum recognition , flat double-girder bridge decks , spectra ;