摘要
This paper presents the flutter derivatives （FDs） extracted from a stochastic system identification （SSI） method under different turbulent flows, The objective of the study is to investigate the effects of oncoming turbulence on the flutter of suspended long-span bridges using a section model wind-tunnel test, Several wind-tunnel tests were performed on a truss bridge deck section with different oncoming turbulent properties involving reduced turbulence intensities and turbulent scales. This study includes an investigation of the effect of oncoming flows on modal dynamic responses. The transient and buffeting response data from the wind-tunnel test are analyzed using the system identification technique in extracting FDs, and the difficulties involved in this method are discussed. The time-domain SSI is applied to extract all FDs simultaneously from one and two degree-of-freedom （1DOF and 2DOF） systems, Finally, the results under different conditions are discussed and conclusions are formed.
本文介绍了在不同湍流条件下通过随机系统识别(SSI)方法提取颤振导数(FD)的过程。研究旨在通过对节段模型风洞试验来研究湍流对悬索式大跨度桥梁的影响。针对不同的湍流特性,对桁架式桥梁断面进行了几项风洞试验,包括降低湍流强度和湍流尺度。研究包括湍流对模型动态响应的影响。利用系统识别技术提取FD,对风洞试验中的瞬态响应和抖振响应进行了分析,同时讨论了该方法存在的困难。利用时域SSI同时从一自由度(1DOF)和二自由度(2DOF)系统提取所有的FD。最后,讨论了不同情况下的结果并得出结论。
