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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。
Aiming at the structural parameter identification under environmental excitation, a method combining wavelet threshold and Independent Component Analysis (ICA) to identify modal parameters of hydraulic structures under water flow excitation is proposed. The original signal is denoised by using the wavelet threshold to reduce the interference of the environmental excitation to the independence of the response components so as to satisfy the separation assumptions of the ICA. Then the ICA is used to identify the structural modal parameters, and through different modes of strain mode Comparison of parameters to achieve the identification of hydraulic structural damage. The results show that the combination of wavelet threshold and ICA can effectively identify the modal parameters of hydraulic structure, and the difference of strain modal parameters can be used to identify whether the structure is damaged or not. This method provides a shortcut for structural modal parameter identification of large hydraulic structures under the excitation of water flow and provides a reference for safe operation and on-line monitoring of structures.