对特征系统实现算法（ERA）进行了改进，采用对构建的新对称矩阵进行特征值分解来替代Hankel矩阵的奇异值分解，提出了计算速度更快、数据储存更少的快速特征系统实现算法（FERA）。首先利用已知的4层框架进行数值模拟，对其施加缩尺的El Centro地震作为未知激励，采用FERA和ERA算法对仿真所得的位移、速度和加速度分别进行模态参数识别，与理论值进行对比结果显示：FERA算法适用于任何动力响应对结构进行模态参数识别，并且其运算速度可较ERA算法有较大提高。此外，FERA算法还被运用到了一座运营中的人行桥环境激励试验中，结果表明该算法同样适用于实际结构的模态参数识别。
Abstract
The proposed fast eigensystem realization algorithm (FERA) is an improvement of the ERA, which can improve the calculation efficiency and cut down the data storage. To avoid the singular value decomposition of Hankel matrix, the eigenvalue decomposition of a newly built symmetric matrix was adopted in the method. Asimulated fourstory frame structure was utilized for validating the accuracy and efficiency of the FERA method. The scaled El Centro earthquake was applied to the structure as an unknown excitation. Both FERA and ERA methods were used for extracting the modal parameters from the simulated displacements, velocities and accelerations, respectively. After comparing the modal analysis results with the analytical values, the conclusions show that the FERA can accurately identify modal parameters from any type of dynamic responses, and the computational speed can increase rapidly. In addition, the FERA was used for extracting modal parameters of an inservice pedestrian bridge through ambient test, and the results show that the proposed method can also work for the actual structure.
关键词
快速特征系统实现 /
环境激励 /
动力响应 /
模态参数识别
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Key words
FERA /
ambient excitation /
dynamic response;modal parameter identification
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