Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection
Ultrasonic guided wave (UGW) detection with fiber Bragg grating (FBG)-based sensors has received increasing attention in the last decades due to the ability to perform non-destructive inspection (NDI) of large plate-like surfaces with a network of lightweight and multiplexed sensors. For accurate UG...
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MDPI AG
2020-11-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/20/22/6571 |
| _version_ | 1827702074968637440 |
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| author | Sidney Goossens Francis Berghmans Thomas Geernaert |
| author_facet | Sidney Goossens Francis Berghmans Thomas Geernaert |
| author_sort | Sidney Goossens |
| collection | DOAJ |
| description | Ultrasonic guided wave (UGW) detection with fiber Bragg grating (FBG)-based sensors has received increasing attention in the last decades due to the ability to perform non-destructive inspection (NDI) of large plate-like surfaces with a network of lightweight and multiplexed sensors. For accurate UGW measurements, several studies concluded that the ratio between the wavelength of the UGW and the length of the FBG should be above 7. However, shorter FBGs suffer from a lower FBG reflectivity and less steep slopes in the reflection spectrum. In this work we experimentally verified the effect of a passing UGW on the Bragg peak of FBG sensors of different lengths. By performing edge-filtering interrogation throughout the FBG’s reflection spectrum, we were able to reconstruct the FBG’s spectral response to a UGW in function of time. Our experimental findings are partially in line with those in the literature considering the UGW wavelength to FBG length ratio and the corresponding Bragg peak changes. We experimentally show for the first time that for shorter FBG sensors, the strain modulation is translated mostly into Bragg peak shifting, while for longer FBG sensors, Bragg peak deformation takes over as main mechanism. Despite the different mechanism for the latter, the UGW can still be detected by edge-filtering on the steepest slope, and with a much higher sensitivity. |
| first_indexed | 2024-03-10T14:47:10Z |
| format | Article |
| id | doaj.art-ced31c7c40094b8a9507ad062270e777 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T14:47:10Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
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| series | Sensors |
| spelling | doaj.art-ced31c7c40094b8a9507ad062270e7772023-11-20T21:17:25ZengMDPI AGSensors1424-82202020-11-012022657110.3390/s20226571Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave DetectionSidney Goossens0Francis Berghmans1Thomas Geernaert2Brussels Photonics (B-PHOT), Department of Applied Physics and Photonics, Vrije Universiteit Brussel and Flanders Make, Pleinlaan 2, B-1050 Brussels, BelgiumBrussels Photonics (B-PHOT), Department of Applied Physics and Photonics, Vrije Universiteit Brussel and Flanders Make, Pleinlaan 2, B-1050 Brussels, BelgiumBrussels Photonics (B-PHOT), Department of Applied Physics and Photonics, Vrije Universiteit Brussel and Flanders Make, Pleinlaan 2, B-1050 Brussels, BelgiumUltrasonic guided wave (UGW) detection with fiber Bragg grating (FBG)-based sensors has received increasing attention in the last decades due to the ability to perform non-destructive inspection (NDI) of large plate-like surfaces with a network of lightweight and multiplexed sensors. For accurate UGW measurements, several studies concluded that the ratio between the wavelength of the UGW and the length of the FBG should be above 7. However, shorter FBGs suffer from a lower FBG reflectivity and less steep slopes in the reflection spectrum. In this work we experimentally verified the effect of a passing UGW on the Bragg peak of FBG sensors of different lengths. By performing edge-filtering interrogation throughout the FBG’s reflection spectrum, we were able to reconstruct the FBG’s spectral response to a UGW in function of time. Our experimental findings are partially in line with those in the literature considering the UGW wavelength to FBG length ratio and the corresponding Bragg peak changes. We experimentally show for the first time that for shorter FBG sensors, the strain modulation is translated mostly into Bragg peak shifting, while for longer FBG sensors, Bragg peak deformation takes over as main mechanism. Despite the different mechanism for the latter, the UGW can still be detected by edge-filtering on the steepest slope, and with a much higher sensitivity.https://www.mdpi.com/1424-8220/20/22/6571fiber Bragg grating (FBG)ultrasonic guided wave (UGW)Lamb wavespectral verification |
| spellingShingle | Sidney Goossens Francis Berghmans Thomas Geernaert Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection Sensors fiber Bragg grating (FBG) ultrasonic guided wave (UGW) Lamb wave spectral verification |
| title | Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection |
| title_full | Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection |
| title_fullStr | Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection |
| title_full_unstemmed | Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection |
| title_short | Spectral Verification of the Mechanisms behind FBG-Based Ultrasonic Guided Wave Detection |
| title_sort | spectral verification of the mechanisms behind fbg based ultrasonic guided wave detection |
| topic | fiber Bragg grating (FBG) ultrasonic guided wave (UGW) Lamb wave spectral verification |
| url | https://www.mdpi.com/1424-8220/20/22/6571 |
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