To reveal the modal information reflected by different measurement points under ambient excitation,a structural seismic response observation array was arranged in Xiamen Fortune Center to obtain structural vibration response.The power spectral density(PSD)curves were obtained using the Welch average periodogram method,and the structural modal parameters were identified on this basis.The PSD curves and modal identification results of different measurement points were compared,In additional,a comparison with the finite element model was completed.The results show that:1)The PSD curves of the structural base,the free site and the bedrock site are highly similar in the frequency range of 0.1-1.0 Hz,which is caused by the secondary microseism of the site.The difference is that the Z-directional peak of the PSD curve at the structural base measurement point is the structural vertical fundamental frequency;while the peak at the free site is the site fundamental frequency.2)The measuring points on the lower floors mainly reflect the modal frequencies in the test direction,while the measuring points of high floors can reflect the modal frequencies in multiple directions.The modal information reflected by the measurement points on high floors is richer,but it is vulnerable to the influence of dense modes.3)The measured results are close to the finite element results,indicating that the finite element model is able to reflect the real dynamic characteristics of the structure.
关键词
结构地震反应观测台阵/环境激励/平均周期图法/结构模态/有限元模型
Key words
structural response observation array/ambient excitation/average periodogram method/structural mo-dal parameters/finite element model
维普
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