Operational modal identification of structures based on improved empirical wavelet transform

This paper proposes an improved Empirical Wavelet Transform (EWT) approach for structural operational modal identification based on measured dynamic responses of structures under ambient vibrations. Two steps are involved in the improved EWT approach. In the first step, the standardized autoregressi...

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Main Authors: Xin, Y., Hao, Hong, Li, Jun
Format: Journal Article
Published: John Wiley & Sons Ltd. 2019
Online Access:http://hdl.handle.net/20.500.11937/73837
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author Xin, Y.
Hao, Hong
Li, Jun
author_facet Xin, Y.
Hao, Hong
Li, Jun
author_sort Xin, Y.
building Curtin Institutional Repository
collection Online Access
description This paper proposes an improved Empirical Wavelet Transform (EWT) approach for structural operational modal identification based on measured dynamic responses of structures under ambient vibrations. Two steps are involved in the improved EWT approach. In the first step, the standardized autoregressive power spectrum of the measured response is calculated to define the boundaries of frequency components for the subsequent EWT analysis. The second step is to decompose the measured response into a number of Intrinsic Mode Functions (IMFs) by using EWT. When the Intrinsic Mode Functions are obtained, structural modal information such as natural frequencies, mode shapes, and damping ratios can be identified by using Hilbert transform and Random Decrement Technique. In numerical studies, a simulated signal is used to investigate the effectiveness of the proposed approach. Operational modal identification based on the proposed approach and procedure is conducted to identify the modal parameters of a simulated spatial frame structure under the ambient excitations. The proposed approach is further used for operational modal identification of a seven-storey shear type steel frame structure in the laboratory and a real footbridge under ambient vibrations to verify the accuracy and performance. The modal identification results from both numerical simulations and experimental validations demonstrate that the proposed approach can effectively and accurately decompose the vibration responses and identify the structural modal parameters under operational conditions.
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institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T10:58:16Z
publishDate 2019
publisher John Wiley & Sons Ltd.
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spelling curtin-20.500.11937-738372019-07-15T03:45:19Z Operational modal identification of structures based on improved empirical wavelet transform Xin, Y. Hao, Hong Li, Jun This paper proposes an improved Empirical Wavelet Transform (EWT) approach for structural operational modal identification based on measured dynamic responses of structures under ambient vibrations. Two steps are involved in the improved EWT approach. In the first step, the standardized autoregressive power spectrum of the measured response is calculated to define the boundaries of frequency components for the subsequent EWT analysis. The second step is to decompose the measured response into a number of Intrinsic Mode Functions (IMFs) by using EWT. When the Intrinsic Mode Functions are obtained, structural modal information such as natural frequencies, mode shapes, and damping ratios can be identified by using Hilbert transform and Random Decrement Technique. In numerical studies, a simulated signal is used to investigate the effectiveness of the proposed approach. Operational modal identification based on the proposed approach and procedure is conducted to identify the modal parameters of a simulated spatial frame structure under the ambient excitations. The proposed approach is further used for operational modal identification of a seven-storey shear type steel frame structure in the laboratory and a real footbridge under ambient vibrations to verify the accuracy and performance. The modal identification results from both numerical simulations and experimental validations demonstrate that the proposed approach can effectively and accurately decompose the vibration responses and identify the structural modal parameters under operational conditions. 2019 Journal Article http://hdl.handle.net/20.500.11937/73837 10.1002/stc.2323 John Wiley & Sons Ltd. restricted
spellingShingle Xin, Y.
Hao, Hong
Li, Jun
Operational modal identification of structures based on improved empirical wavelet transform
title Operational modal identification of structures based on improved empirical wavelet transform
title_full Operational modal identification of structures based on improved empirical wavelet transform
title_fullStr Operational modal identification of structures based on improved empirical wavelet transform
title_full_unstemmed Operational modal identification of structures based on improved empirical wavelet transform
title_short Operational modal identification of structures based on improved empirical wavelet transform
title_sort operational modal identification of structures based on improved empirical wavelet transform
url http://hdl.handle.net/20.500.11937/73837