Modal Parameter Identification of Beam Structures Based on Improved Empirical Fourier Decomposition
摘要
To improve the accuracy of modal parameter identification in beam structures, this study presents an enhanced empirical Fourier decomposition (EFD) methodology for signal decomposition and modal parameter recognition under environmental excitations.
MethodsThe proposed identification framework comprises two key innovations: First, we implement multiple signal classification (MUSIC) to determine optimal frequency segmentation boundaries, effectively replacing conventional Fourier spectrum analysis that demonstrates vulnerability to noise contamination. Second, we develop an improved EFD variant (designated as EFDM) to decompose acquired vibration responses into distinct modal components.
ResultsSubsequent processing involves extracting free vibration responses from these modal components through synergistic application of Hilbert transform (HT) and random decrement technique (RDT), enabling precise identification of structural modal parameters. Comprehensive numerical simulations and experimental validations substantiate the method's enhanced identification accuracy and operational robustness, particularly demonstrating superior noise immunity compared to conventional approaches.
ConclusionThe results confirm the methodology's effectiveness in practical structural health monitoring applications, offering improved reliability in ambient vibration analysis scenarios.