桥梁颤振导数自由振动识别的分段扩阶最小二乘迭代算法

研究了利用节段模型风洞试验的自由振动信号直接识别系统矩阵的时域法。在可识别性研究的基础上，给出了最小二乘一次完成算法、倒置时序算法、分段识别算法和分段扩阶最小二乘迭代算法（SEO-ILS法）。随后SEO-ILS法用于桥梁颤振导数识别：先直接识别出系统矩阵，在识别出二自由度节段模型各不同风速下的等效刚度和等效阻尼矩阵后，即可同时提取8个颤振导数。风洞试验表明，文中方法有效可行。

SUBSECTION EXTENDED ORDER ITERATIVE LEAST SQUARE ALGORITHM FOR IDENTIFICATION OF BRIDGE FLUTTER DERIVATIVES FROM FREE VIBRATION DATA

Time domain method of direct identification fo system matrix from free vibration data of a bridge deck sectional model in wind trnnel test is investigated.Based on the identification capability theory,the one-step finished least square algorithm and the inverse time series algorithm are presented in this paper.Considering effects of both system and proocess noise,the subsection identification algorithm and the Subsection Extended Order Iterative Least Square algorithm(SEO-ILS) are developed,too.Then,the SEO-ILS technique has been applied to extract flutter derivatives of Bridges from free vibration data of section model test.First,the system matrix is identifed directly,after the equivalent damping matrix and the equivalent stiffness matrix of the two degrees of freedom section model are identfied,eight flutter derivatives are extracted simultaneously.All eight flutter derivatives of a thin plate and a bridge deck section model are identified to show the reliability and effectiveness of the SEO-ILS method.