摘要
提出了一种基于频域空间域分解(Frequency and Spatial Domain Decomposition,FSDD)的运行模态分析方法。该法将同时具有输入和输出的试验模态分析的经典方法———复模态指示因子(Complex Mode In-dicator Function,CMIF)法拓展到了仅有输出响应的运行状态模态分析。FSDD法采用奇异值分解将信号空间和噪声空间分离开来,把奇异值曲线作为模态指示的依据,以奇异值向量作为加权函数得到每一阶模态的增强功率谱(Power Spectrum Density,PSD),进而在频域内对增强PSD曲线进行最小二乘拟合以得到准确的模态频率和阻尼参数。采用了一个二层楼仿真算例和在欧洲广为人知的瑞士Z24公路大桥实测算例来验证FSDD算法。
A frequency and spatial domain decomposition （FSDD） method for operational modal analysis （OMA） is presented in this paper, which is an extension of Complex Mode Indicator Function （CMIF） method for experimental modal analysis （EMA）. Singular value decomposition is adopted to separate the signal space from the noise space. The singular values plot is a good indicator for locating modal frequencies. The singular vectors are employed as a weight function to obtain an enhanced power spectrum density （PSD）, from which accurate modal frequency and damping ratio are got through the least square fitting in frequency domain. A simulation case of a two-storey building and an application case of the famous Z24 highway bridge are employed to validate the FSDD algorithm.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2006年第1期62-66,共5页
Acta Aeronautica et Astronautica Sinica
基金
中国博士后科学基金(2004035215)
江苏省博士后科研资助计划
航空科学基金(04I52065)资助项目
关键词
模态参数识别
运行模态分析
频域空间域
最小二乘拟合
modal parameters identification
operational modal analysis
frequency and spatial domain
least square fitting
