SummaryModal identification method based on blind source separation (BSS) technique has gained extensive attentions for civil structures. Developing the complex modes estimation method is important in practical applications because the assumption of proportional damping is not always satisfied. Sparse component analysis (SCA) performs well in underdetermined BSS problems. However, SCA is confined to the situation of proportional damping. In this study, a generalized SCA method is proposed to extend the original SCA method to both real and complex modes identification. First, the general formulation of complex modes is extended by the analytic form to eliminate the complex conjugate part in the BSS model. A new single‐source‐point detection method that is available to handle real and complex modes is proposed. Local outlier factor method is adopted to remove the outliers in single source points. Subsequently, complex‐valued modal matrix is calculated by the clustering technique. Then, modal responses are recovered using the complex version of smoothed zero norm method, where modal frequencies and damping ratios can be extracted. Finally, the effectiveness of the proposed method is demonstrated for identification of real and complex modes, close modes, and underdetermined problem. The application to a benchmark structure demonstrates the effectiveness for practical applications.

中文翻译：

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使用广义稀疏分量分析进行非经典阻尼结构的模态识别

摘要基于盲源分离（BSS）技术的模态识别方法在土木结构中得到了广泛的关注。开发复模态估计方法在实际应用中非常重要，因为并不总是满足比例阻尼的假设。稀疏分量分析 (SCA) 在欠定 BSS 问题中表现良好。然而，SCA仅限于比例阻尼的情况。在本研究中，提出了一种广义的SCA方法，将原始的SCA方法扩展到实模态和复模态识别。首先，通过解析形式扩展复模态的一般公式，以消除BSS模型中的复共轭部分。提出了一种新的单源点检测方法，可用于处理实数和复杂模式。采用局部异常值因子法去除单源点的异常值。随后，通过聚类技术计算复值模态矩阵。然后，使用平滑零范数方法的复杂版本恢复模态响应，其中可以提取模态频率和阻尼比。最后，证明了该方法对于识别真实和复杂模式、封闭模式和欠定问题的有效性。基准结构的应用证明了实际应用的有效性。