Acoustic emission source linear localization based on an ultra-short FBGs sensing system

Abstract

An acoustic emission (AE) linear location system was proposed, which employed fiber Bragg gratings (FBGs) as AE sensors. It was demonstrated that the FBG wavelength could be modulated as the static case when the grating length was much shorter than the AE wavelength. In addition, an improved AE location method based on the Gabor wavelet transform (WT) and threshold analysis was represented. The method was testified through AE linear location experiments based on a tunable narrow-band laser interrogation system using ultra-short FBG sensors as AE sensors. Results of the experiments showed that 86% of the linear location errors were less than 10 mm.

Keywords

Acoustic emission (AE) linear location / fiber Bragg gratings (FBGs) / Gabor wavelet transform (WT) / threshold analysis

References

[1] Othonos A. Fiber Bragg gratings. Review of Scientific Instruments, 1997, 68(12): 4309-4341.

[2] Fernando G F, Webb D J, Ferdinand P. Optical-fiber sensors. MRS Bulletin, 2002, 2705, 359-364.

[3] Minardo A, Cusano A, Bernini R, Zeni L, Giordano M. Response of fiber Bragg gratings to longitudinal ultrasonic waves. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 2005, 52(2): 304-312.

[4] Lee J R, Tsuda H. Sensor application of fibre ultrasonic waveguide. Measurement Science and Technology, 2006, 17(4): 645-652.

[5] Lee J R, Tsuda H. Investigation of a fibre wave piezoelectric transducer. Measurement Science and Technology, 2006, 17(9): 2414-2420.

[6] Lee J R, Lee S S, Yoon D J. Simultaneous multipoint acoustic emission sensing using fibre acoustic wave grating sensors with identical spectrum. Journal of Optics A: Pure and Applied Optics, 2008, 10(8): 085307.

[7] Kwon O Y, Joo Y C. Source location in plates by using wavelet transform of AE signals. Journal of Acoustic Emission, 1998, 16(1–4): S212-S221.

[8] Jeong H, Jang Y S. Fracture source location in thin plates using the wavelet transform of dispersive waves. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 2000, 47(3): 612-619.

[9] Culshaw B, Thursby G, Betz D, Sorazu B. The detection of ultrasound using fiber-optic sensors. Sensors Journal, IEEE, 2008, 8(7): 1360-1367.

[10] Zhou C, Zhang Y. Fatigue crack localization with near-field acoustic emission signals. Proc. SPIE International Society for Optics and Photonics, 2013, 8692, 86920L-1-86920L-9.