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Indexed by:期刊论文

Date of Publication:2019-03-01

Journal:JOURNAL OF AEROSPACE ENGINEERING

Included Journals:SCIE

Volume:32

Issue:2

ISSN No.:0893-1321

Key Words:Eigensystem realization algorithm; Automated modal identification; Clustering

Abstract:The subject of vibration-based structural health monitoring (SHM) has attracted increasing attention, especially in the field of civil engineering. However, the development of these monitoring processes is not a simple task, with user interaction playing a significant role in the extraction of modal characteristics. In this paper, an automated operational modal analysis methodology based on an eigensystem realization algorithm (ERA) and a two-stage clustering strategy is proposed. Three crucial steps are addressed in this study. In the first phase, ERA is adopted to calculate modes from state-space models of different orders. Subsequently, the dissimilarity of modal parameters is employed as the features of fuzzy C-means (FCM) clustering to separate stable modes from unstable ones. The final step consists of grouping stable modes with similar structural properties to select physical modes. No user-specified parameter is required in the clustering procedure to single out physical modes. A practical bridge example is used to verify that the proposed method can estimate modal parameters effectively in real time.