Studying the effect of strain induced birefringence on the sensitivity of FBG sensors for Guided wave measurements

Studying the effect of strain induced birefringence on the sensitivity of FBG sensors for Guided wave measurements

Soman, Rohan (Polish Academy of Sciences)
Fazzi, L. (TU Delft Structural Integrity & Composites)
Nokhbatolfoghahai, A. (TU Delft Structural Integrity & Composites)
Groves, R.M. (TU Delft Structural Integrity & Composites)
Ostachowicz, Wieslaw (Polish Academy of Sciences)

Fromme, Paul (editor)
Su, Zhongqing (editor)

2022

To perform active structural health monitoring (SHM), guided waves (GW) have received great interest as they can inspect large areas with a few sensors and are sensitive to barely-visible structural damages. Fiber Bragg grating (FBG) sensors offer several advantages such as small size, low weight and ability to be embedded but their use has been limited for GW sensing due to their limited sensitivity while using spectrometers. FBG sensors in the edge-filtering configuration have overcome this issue with reasonable sensitivity and there is a renewed interest in their use. It is well known that when subjected to a transverse strain, the circular cross-section of the fiber deforms into an elliptical shape generating the birefringence phenomenon. This deformation, influences the coupling mode of the light inside the FBG and hence, modifies the resulting reflectivity spectrum. This paper investigates how controlled changes in the reflectivity spectrum can be introduced using different transverse loads. The effect of the modified spectrum on the sensitivity of the FBG for GW measurements is then studied. The study also investigates the effect of the transverse strain on the coupling of the GW from the structure into the fiber.

fiber Bragg grating birefringence
fiber optic sensors
guided waves
plate
sensitivity

http://resolver.tudelft.nl/uuid:c7e51e9f-bda4-42ce-a625-c94ca07d391f

https://doi.org/10.1117/12.2612487

SPIE

2023-07-01

9781510649712

Health Monitoring of Structural and Biological Systems XVI

Health Monitoring of Structural and Biological Systems XVI 2022, 2022-04-04 → 2022-04-10, Virtual, Online

Proceedings of SPIE - The International Society for Optical Engineering, 0277-786X, 12048

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

conference paper

© 2022 Rohan Soman, L. Fazzi, A. Nokhbatolfoghahai, R.M. Groves, Wieslaw Ostachowicz