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研究网壳结构在环境激励下的模态参数识别问题。采用模型试验的方法,通过试验模态和运行模态的分析方法和结果的对比,分析自然激励下参与网壳结构振动的模态阶次和参与程度、虚假模态的辨别以及频域分解法识别模态参数的准确度等问题。试验结果表明:对于具有密集模态的网壳结构,高阶模态主要参与环境激励下的结构响应,得到如下结论:使用频域分解法得到的模态频率识别值准确度高,对于参与结构振动程度强的模态,振型识别的准确度高;提出可以根据模态频率对应的奇异值大小进行虚假模态的辨别,奇异值最大的模态,识别准确度最高,可被认为是真实模态。
Research on modal parameter identification of reticulated shell under environmental excitation. By means of the model test, the modal order and degree of participation of natural reticulated shell structures subjected to natural excitation, the identification of false modalities, and the frequency domain decomposition method are analyzed by comparing the analysis methods and results of the experimental modal and the operational modal. Identify the accuracy of modal parameters and other issues. The experimental results show that for the reticulated shell structure with high density, the high-order modal is mainly involved in the structural response under environmental excitation. The conclusions are as follows: The modal frequency identification value obtained by the frequency-domain decomposition method is of high accuracy, Strong modal and high accuracy of modal identification. It is proposed that the false modal can be distinguished according to the value of the singular value of the modal frequency, and the mode with the largest singular value has the highest recognition accuracy and can be regarded as the real mode .