基于节段同步测力的桁架梁二维气动导纳直接识别

Direct identification of two-dimensional aerodynamic admittance of truss girder based on synchronous segmental force-balance measurements

基于节段同步测力技术,推导桁架梁二维气动导纳的直接识别法,并研究湍流场非各向同性成分对二维气动导纳识别的影响。研究结果表明:直接识别法能有效识别桁架梁二维气动导纳;有必要修正湍流场非各向同性成分,以保证二维气动导纳识别不受抖振力展向相干函数组合选取的影响;桁架梁二维气动导纳大于其三维气动导纳,升力二维气动导纳在高频段大于相应Sears函数值;基于节段同步测力技术提出的桁架梁二维气动导纳直接识别法适用于其他桥梁断面(例如流线型箱梁断面)的二维气动导纳识别。

A direct identification method for two-dimensional aerodynamic admittance of the truss girder was derived based on the technology of synchronous segmental force-balance measurement, and the influence of nonisotropic components of turbulent flow on the two-dimensional aerodynamic admittance was investigated. The results show that the proposed method can effectively identify two-dimensional aerodynamic admittance of the truss girder. It is necessary to correct the non-isotropic components of the turbulence flow to ensure that twodimensional aerodynamic admittance is not affected by the combination of buffeting force coherence function. The two-dimensional aerodynamic admittance of the truss girder is greater than its three-dimensional aerodynamic admittance. The two-dimensional aerodynamic admittance of lift is larger than the corresponding value of the Sears function in the high-frequency range. The direct identification method of two-dimensional aerodynamic admittance of the truss girder based on synchronous segmental force-balance measurement can be applied on bridge decks of arbitrary cross-section such as streamlined bridge deck.