Trans-Jacket Fibre Bragg Gratings for In-Situ Health Monitoring of Defence Platforms in Harsh Environments

Trans-Jacket Fibre Bragg Gratings for In-Situ Health Monitoring of Defence Platforms in Harsh Environments

Naizhong Zhang, Claire Davis, Chiu Wing Kong, Suzana Turk

Abstract. Packaged optical fibre sensors offer excellent strength and resistance to environmental degradation, but the reported reliability and durability of fibres containing fibre Bragg gratings (FBGs) varies greatly. This is partly due to the fabrication methodologies used to create the sensors. The trans-jacket grating inscription technique uses an infrared laser to write gratings into the fibre core through the polymer coating. This method eliminates the need for harsh coating removal processes and exposure of the glass fibre core and thus dramatically reduces fibre damage during grating fabrication. In addition, the automated trans-jacket inscription process introduces greater flexibility to control the writing parameters, facilitating a consistent process for producing robust, fatigue resistant distributed FBG sensing arrays with reliable and repeatable performance that could revolutionise their application in structural health monitoring (SHM). This paper reports on the durability and reliability of Bragg gratings with different fibre geometries, dopants, and photo-sensitising approaches to compare the overall fatigue performance of trans-jacket FBG sensors. Both type I gratings which are inscribed using a laser power intensity below the damage threshold of the glass core, and type II gratings which are inscribed exceeding this threshold, are considered. The fatigue performance of these FBG sensors was assessed using a custom designed electro-dynamically actuated loading assembly. It is concluded that type I trans-jacket gratings have a significantly higher fatigue life compared to type II gratings for the same fatigue loading regime. Despite the lower fatigue life, type II trans-jacket gratings are found to perform significantly better than conventional electrical foil gauges. Therefore, trans-jacket gratings have significant potential for application as dense sensing arrays in harsh operational environments in defence and aerospace industries.

Keywords
Optical Fibre Sensors, Fibre Bragg Gratings, Grating Inscription, Trans-Jacket Gratings, Sensor Fatigue

Published online 2/20/2021, 8 pages
Copyright © 2021 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: Naizhong Zhang, Claire Davis, Chiu Wing Kong, Suzana Turk, Trans-Jacket Fibre Bragg Gratings for In-Situ Health Monitoring of Defence Platforms in Harsh Environments, Materials Research Proceedings, Vol. 18, pp 45-52, 2021

DOI: https://doi.org/10.21741/9781644901311-6

The article was published as article 6 of the book Structural Health Monitoring

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] G. Meltz, W. W. Morey, and W. H. Glenn, “Formation of Bragg gratings in optical fibers by a transverse holographic method,” Opt. Lett., 1989, doi: 10.1364/ol.14.000823. https://doi.org/10.1364/OL.14.000823
[2] R. Kashyap, Fiber Bragg Gratings. 2010. https://doi.org/10.1016/B978-0-12-372579-0.00004-1
[3] A. D. Kersey et al., “Fiber grating sensors,” J. Light. Technol., vol. 15, no. 8, pp. 1442–1462, 1997. https://doi.org/10.1109/50.618377
[4] Y. J. Rao, “In-fibre Bragg grating sensors,” Meas. Sci. Technol., vol. 8, no. 4, pp. 355–375, 1997. https://doi.org/10.1088/0957-0233/8/4/002
[5] M. Majumder, T. K. Gangopadhyay, A. K. Chakraborty, K. Dasgupta, and D. K. Bhattacharya, “Fibre Bragg gratings in structural health monitoring-Present status and applications,” Sensors and Actuators, A: Physical. 2008. https://doi.org/10.1016/j.sna.2008.04.008
[6] R. Di Sante, “Fibre optic sensors for structural health monitoring of aircraft composite structures: Recent advances and applications,” Sensors (Switzerland). 2015. https://doi.org/10.3390/s150818666
[7] R. Ramly, W. Kuntjoro, and M. K. A. Rahman, “Using embedded fiber bragg grating (FBG) sensors in smart aircraft structure materials,” 2012. https://doi.org/10.1016/j.proeng.2012.07.218
[8] K. C. Chuang and C. C. Ma, “Tracking control of a multilayer piezoelectric actuator using a fiber bragg grating displacement sensor system,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 2009. https://doi.org/10.1109/TUFFC.2009.1287
[9] M. W. Rothhardt, C. Chojetzki, and H. R. Mueller, “High-mechanical-strength single-pulse draw tower gratings,” 2004. https://doi.org/10.1117/12.567801
[10] K. O. Hill and G. Meltz, “Fiber Bragg grating technology fundamentals and overview,” J. Light. Technol., 1997. https://doi.org/10.1109/50.618320
[11] H. J. Yoon and C. G. Kim, “The mechanical strength of fiber Bragg gratings under controlled UV laser conditions,” Smart Mater. Struct., 2007. https://doi.org/10.1088/0964-1726/16/4/045
[12] J. Ang, H. C. H. Li, I. Herszberg, M. K. Bannister, and A. P. Mouritz, “Tensile fatigue properties of fibre Bragg grating optical fibre sensors,” Int. J. Fatigue, 2010. https://doi.org/10.1016/j.ijfatigue.2009.11.002
[13] M. Bernier, F. Trépanier, J. Carrier, and R. Vallée, “High mechanical strength fiber Bragg gratings made with infrared femtosecond pulses and a phase mask,” Opt. Lett., vol. 39, no. 12, p. 3646, 2014. https://doi.org/10.1364/OL.39.003646
[14] J. Habel, T. Boilard, J. S. Frenière, F. Trépanier, and M. Bernier, “Femtosecond FBG written through the coating for sensing applications,” Sensors (Switzerland), vol. 17, no. 11, pp. 1–12, 2017. https://doi.org/10.3390/s17112519
[15] C. W. Smelser, S. J. Mihailov, and D. Grobnic, “Formation of Type I-IR and Type II-IR gratings with an ultrafast IR laser and a phase mask,” Opt. Express, 2005. https://doi.org/10.1364/OPEX.13.005377
[16] L. Sudrie, M. Franco, B. Prade, and A. Mysyrowicz, “Study of damage in fused silica induced by ultra-short IR laser pulses,” Opt. Commun., 2001. https://doi.org/10.1016/S0030-4018(01)01152-X
[17] C. Davis, S. Tejedor, I. Grabovac, J. Kopczyk, and T. Nuyens, “High-strain fiber bragg gratings for structural fatigue testing of military aircraft,” Photonic Sensors, 2012. https://doi.org/10.1007/s13320-012-0066-3
[18] “The Fatigue Life of Electrical Strain Gauges,” HBM, 2020. https://www.hbm.com/en/8153/new-technote-fatigue-life-of-electrical-strain-gauges/ (accessed Oct. 27, 2020).
[19] J. C. Middleton, “Strain gauge performance during fatigue testing,” Strain, vol. 22, no. 3, pp. 135–140, 1986. https://doi.org/10.1111/j.1475-1305.1986.tb00608.x
[20] N. Zhang, C. Davis, W. K. Chiu, T. Boilard, and M. Bernier, “Fatigue performance of type I fibre bragg grating strain sensors,” Sensors (Switzerland), vol. 19, no. 16. 2019. https://doi.org/10.3390/s19163524
[21] S. R. Abdullina and A. A. Vlasov, “Suppression of side lobes in the fiber Bragg grating reflection spectrum,” Optoelectron. Instrum. Data Process., 2014. https://doi.org/10.3103/S8756699014010105
[22] C. W. Smelser, S. J. Mihailov, and D. Grobnic, “Hydrogen loading for fiber grating writing with a femtosecond laser and a phase mask,” Opt. Lett., vol. 29, no. 18, p. 2127, 2004. https://doi.org/10.1364/OL.29.002127