Share Email Print
cover

Proceedings Paper • new

Effect of continuous optical fiber bonding on ultrasonic detection using fiber Bragg grating
Author(s): Junghyun Wee; Drew Hackney; Philip Bradford; Kara Peters
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

For laboratory demonstrations, Lamb wave detection using fiber Bragg grating (FBG) sensors is typically performed with only the grating location spot bonded and with the fiber axis aligned with the ultrasonic propagation direction. However, in reality, the entire length of fiber is often bonded to protect the fiber from any environmental damage, referred to here as continuous bonding. Theoretically, the Lamb wave signal can couple to the guided traveling wave in the optical fiber at any adhered location, which could potentially produce output signal distortion. In this paper, we investigate the impact of continuously bonding a long length of optical fiber on the measured Lamb wave signal detected by an FBG. Therefore, an experiment is performed to measure the Lamb wave signals excited from a PZT actuator using a surface bonded FBG with varying optical fiber bond length, indicating that the output FBG response remains constant with changing length. The second experiment investigates the FBG angular response to the traveling wave in the optical fiber, and compares to the conventional case where FBG directly measures the Lamb waves with varying angle. Specifically, the optical fiber is bonded to the plate at a distance away from the FBG. The Lamb wave is launched to the bond location with varying angles, which is coupled to traveling wave, then measured with FBG. The results indicate that the mechanism of the Lamb wave transfer to the directly bonded FBG is through displacement matching, whereas that of the traveling wave is through a forced excitation.

Paper Details

Date Published: 27 March 2018
PDF: 7 pages
Proc. SPIE 10598, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2018, 1059838 (27 March 2018); doi: 10.1117/12.2295833
Show Author Affiliations
Junghyun Wee, North Carolina State Univ. (United States)
Drew Hackney, North Carolina State Univ. (United States)
Philip Bradford, North Carolina State Univ. (United States)
Kara Peters, North Carolina State Univ. (United States)


Published in SPIE Proceedings Vol. 10598:
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2018
Hoon Sohn, Editor(s)

© SPIE. Terms of Use
Back to Top