Insights on the Bayesian spectral density method for operational modal analysis

Au, Siu-Kui ORCID: 0000-0002-0228-1796 (2016) Insights on the Bayesian spectral density method for operational modal analysis. MECHANICAL SYSTEMS AND SIGNAL PROCESSING, 66-67. pp. 1-12.

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Abstract

This paper presents a study on the Bayesian spectral density method for operational modal analysis. The method makes Bayesian inference of the modal properties by using the sample power spectral density (PSD) matrix averaged over independent sets of ambient data. In the typical case with a single set of data, it is divided into non-overlapping segments and they are assumed to be independent. This study is motivated by a recent paper that reveals a mathematical equivalence of the method with the Bayesian FFT method. The latter does not require averaging concepts or the independent segment assumption. This study shows that the equivalence does not hold in reality because the theoretical long data asymptotic distribution of the PSD matrix may not be valid. A single time history can be considered long for the Bayesian FFT method but not necessarily for the Bayesian PSD method, depending on the number of segments.

Item Type:	Article
Uncontrolled Keywords:	Bayesian FFT method, Bayesian spectral density method, Ambient modal identification, Operational modal analysis, Spectral leakage
Depositing User:	Symplectic Admin
Date Deposited:	12 Sep 2016 08:35
Last Modified:	19 Jan 2023 07:30
DOI:	10.1016/j.ymssp.2015.04.023
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3003223