Displacement Reconstruction and Frequency Analysis of Cantilever Beams Using Multi-Segment FBG Sensor
Journal
IEEE Sensors Journal
ISSN
1530437X
Date Issued
2025
Author(s)
Abstract
This study proposes a fiber Bragg grating (FBG) sensing system integrated with the conjugate beam method (CBM) and frequency analysis to reconstruct the deformation of cantilever beams. Distributed strain data from the FBG array were transformed into displacement profiles and subsequently validated against beam theory and finite element method (FEM). The reconstructed deformation exhibited close agreement, with root-mean-square error typically below 2% under static loading, confirming the accuracy and reliability of the FBG–CBM methodology in static deformation measurement. Besides, in the dynamic domain, the extracted modal frequencies closely matched FEM predictions, while frequency-domain analysis demonstrated the system’s ability to capture broadband resonant responses up to 14 kHz. Modal amplitudes obtained via (short-time) Fast Fourier Transform were incorporated into the reconstruction, enabling dynamic displacement estimation, accurate modal identification, and damping ratio. The resonant frequency and mode shape have a root-mean-square error of less than 0.2% and 4.41%, respectively, compared to the FEM and theoretical solutions. These results highlight the dual capability of the proposed FBG sensing technology for both displacement reconstruction and frequency characterization, demonstrating its suitability for compact and scalable structural health monitoring in beam structures.
Subjects
Conjugate Beam Method
Displacement Reconstruction
Dynamic Response
Fiber Bragg Grating Sensing
SDGs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article