摘要

The flutter stability of bridges could be evaluated based on the wind tunnel test. However, the spatial distribution of the surface pressures on the section is unclear. In this paper, the surface pressures of the flexible suspension rigid model in the static and fluttering condition are both acquired with the same flow velocity. Based on analyzing the distribution of the surface pressures, the relationship between the pressures and flutter is gained by the proper orthogonal decomposition (POD) method. The result shows that one of the eigen modes has a strong association to the flutter with a dominant role to the torsion coeffience, so this mode is called'dominant flutter mode'. Meanwhile, its normalized spatial distribution remains unchange during fluttering with the same frequency and divergence of the vibration. The other modes are hardly relevance to the flutter. We can also find that the pressure of the right part of the section is lagged to the left part since the right part is the passive region with the impact of the characteristic turbulence of the windward. Comparing with the result of the static condition, there is no any other similar modes expect the 'dominant flutter mode'. This paper will provide a new method to research the flutter mechanism.

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