针对环境激励下的结构参数辨识问题，提出一种小波阈值和独立分量分析（Independent Component Analysis, ICA）联合辨识水流激励下水工结构模态参数的方法。利用小波阈值对原始信号进行降噪处理，减小环境激励对各响应分量间独立性的干扰，使其满足ICA的分离假定；然后运用ICA辨识结构模态参数，通过不同工况下应变模态参数的对比，实现对水工结构损伤的识别。运用该方法对水流激励下的悬臂梁模型试验进行分析研究，结果表明，联合运用小波阈值和ICA可有效辨识水工结构的模态参数，利用应变模态参数的差异可识别结构是否存在损伤。该方法为大型水工结构在水流激励下的结构模态参数辨识提供捷径，为结构的安全运行与在线监测提供参考，应用前景广阔。
Abstract
In view of the problem that the modal parameters of structure under environmental excitation extracted difficultly, a kind of combined wavelet threshold and Independent Component Analysis (ICA) modal parameter identification method of hydraulic structure is proposed. Firstly a part of noises were filtered out with wavelet threshold, which can reduce the environmental excitation response to each component of independence and make it meet the ICA separation assumption; Then identifying structural modal parameters by using ICA, damage identification of hydraulic structure obtained through the contrast of the strain modal parameters under different working conditions. It is used in cantilever beam model test under the current excitation. The results show that, combined wavelet threshold and ICA can effectively identify modal parameters of the hydraulic structure, the difference of which can identify structure whether there is any damage. This proposed method can effectively solve the problem of modal parameter identification for large hydraulic structure under the environmental excitation, which has a broad prospect in providing the reference for safe operation and on-line monitoring of structure.
关键词
环境激励 /
水工结构 /
小波分析 /
独立分量分析 /
损伤识别
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Key words
ambient excitation /
hydraulic structure /
wavelet analysis /
Independent Component Analysis /
damage identification
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参考文献
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