桥梁颤振气动导数在均匀流与紊流作用下的统一辨识理论研究

Uniform Identification Theory of Bridge Flutter Derivatives under Smooth Flow and Turbulent Flow

桥梁断面颤振气动导数的准确识别是桥梁空气动力稳定性研究的基础,一直是桥梁风工程研究领域的前沿课题。基于工况模态分析理论,本文首先导出了紊流条件下桥梁颤振气动导数辨识的完整方法;其次,将上述数据处理方式运用到由均匀流条件引起的自由衰减振动中,得出与紊流情况类似的结果。本文提出的方法能够用同样的辨识原理、同一个数据处理程序统一地对紊流和均匀流下的桥梁气动导数进行辨识;最后,利用数值仿真算例验证上述理论。

The exact identification of flutter derivatives is the basic of the bridge aerodynamic stability analysis. It is always the key subject in the field of the bridge wind engineering research for its difficulty. Based on the operational modal analysis theory, the complete indentification method of flutter derivatives was educed under the condition of turbulent flow. Secondly, the program of above method to deal with the data of free attenuating vibratin caused by smooth flow was used. A similar result with turbulent flow was datained. The method can uniformly identify the bridge flutter derivatives under the condition of turbulent flow and smooth flow with the same identification theory and the same data processing program. Finally, the above theory was validated by simulation cases.