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Indexed by:会议论文

Date of Publication:2017-12-05

Page Number:587-593

Abstract:During damage identification or assessment of bridges, the modal parameters, such as frequency, damping and modal shape are also utilized, which shows the importance to identify the modal parameters precisely. Eigensystem realization algorithm (ERA) is one of the most popular identification methods. However,the noises in practical environment can influent the effectiveness of ERA, which can introduce spurious modes. This paper proposes an improved ERA to distinguish the spurious modes. Any two Hankel matrices with one time step shift used in ERA have been proved. The singular value matix is obtained by singular value decomposition of Hankel matrix, whose rank is concerned by truncated the different singular values. The noises can make the singular values hard to be truncated. Through moving the start point of time recording to compose two Hankel matrices can help to observe the change of singular values. If the singular vaues are changed with the moving time recording, the identified modes are spurious. To determine the rank initially, the stabilization diagram is employed, which can give the interested modes first that may contain spurious. Then the moving data diagram can be built to show the singular value changing, which picks the exact modes. Finally, the proposed method is verified by a numerical example. The results demonstrate that the improved ERA can distinguish the spurious modes. © 2017 International Society for Structural Health Monitoring of Intelligent Infrastrucure. All rights reserved.