Investigation of Strain-Temperature Cross-Sensitivity of FBG Strain Sensors Embedded Onto Different Substrates

Abstract

The strain-temperature cross-sensitivity problem easily occurs in the engineering strain monitoring of the self-sensing embedded with fiber Bragg grating (FBG) sensors. In this work, a theoretical investigation of the strain-temperature cross-sensitivity has been performed using the temperature reference grating method. To experimentally observe and theoretically verify the problem, the substrate materials, the preloading technique, and the FBG initial central wavelength were taken as main parameters. And a series of sensitivity coefficients calibration tests and temperature compensation tests have been designed and carried out. It was found that when the FBG sensors were embedded on different substrates, their coefficients of the temperature sensitivity were significantly changed. Besides, the larger the coefficients of thermal expansion (CTE) of substrates were, the higher the temperature sensitivity coefficients would be. On the other hand, the effect of the preloading technique and FBG initial wavelength was negligible on both the strain monitoring and temperature compensation. In the case of similar substrates, we did not observe any difference between temperature sensitivity coefficients of the temperature compensation FBG with one free end or two free ends. The curves of the force along with temperature were almost overlapped with minor differences (less than 1%) gained by FBG sensors and pressure sensors, which verified the accuracy of the temperature compensation method. We suggest that this work can provide efficient solutions to the strain-temperature cross-sensitivity for engineering strain monitoring with the self-sensing element embedded with FBG sensors.

Keywords

FBG sensor / self-sensing element embedded FBG sensor / cross sensitivity of strain and temperature / temperature compensation

References

[1] Yao G W, Yu X R, Gu L F, Jiang Y X. Experiment on corrosion fatigue life of steel strands under the coupling effects of chloride environment and alternating loads. Advances in Civil Engineering, 2021, 2021, 2439503.

[2] Wang P, Zhang L, Wang F M, Zhang Z P, He Y. The time-dependent effect of corrosion of steel strands on prestressed concrete beam bridges. Applied Mechanics and Materials, 2014, 638, 1038-1044.

[3] Lan C, Xu Y, Liu C, Li H, Spencer B F Jr. Fatigue life prediction for parallel-wire stay cables considering corrosion effects. International Journal of Fatigue, 2018, 114, 81-91.

[4] Liu Z, Huang Q, Shan Y, Chen J. Quantifying high temperature — induced breakage instant of prestressing high-strength steel wire. Journal of Materials in Civil Engineering, 2020, 32(7): 04020189.

[5] Lan C M, Yang H T, Bai N N, Liu C P. Probabilistic model for fatigue life evaluation of corroded prestressing strand. China Civil Engineering Journal, 2018, 51(10): 68-77.

[6] S. L. Huang, B. Q. Tao, and Y. P. Shen, “Intelligent structure systems: dream, reality, and future,” in World Forum on Smart Materials & Smart Structures, China, 2007, pp. 22–27.

[7] Brownjohn J M W. Structural health monitoring of civil infrastructure. Philosophical Transactions Mathematical Physical & Engineering Sciences, 2007, 365(1851): 589-622.

[8] Ou J P. Monitoring and maintenance of large bridge life cycle performance. China Highway, 2017, 13, 42-45.

[9] Sun L M, Shang Z Q, Xia Y. Development and prospect of bridge structural health monitoring in the context of big data. China Journal of Highway and Transport, 2019, 32(11): 1-20.

[10] J. M. Kim, H. W. Kim, S. Y. Choi, and S. Y. Park, “Measurement of prestressing force in pretensioned UHPC deck using a fiber optic FBG sensor embedded in a 7-wire strand,” Journal of Sensors, 2016, (2016): 1–9.

[11] Kong X, Zhang J, Deng L, Liu Y K. Research advances on vehicle parameter identification based on machine vision. China Journal of Highway and Transport, 2021, 34(4): 13.

[12] Li D, Zhou Z, Ou J P. Dynamic behavior monitoring and damage evaluation for arch bridge suspender using GFRP optical fiber Bragg grating sensors. Optics & Laser Technology, 2012, 44(4): 1031-1038.

[13] Xiong C B, Lu H L, Zhu J S, Yu J Y. Dynamic deformation monitoring of bridge structures based on GPS-RTK and accelerometers. Journal of Vibration and Shock, 2019, 38(12): 69-73.

[14] Lan C, Zhou Z, Ou J P. Monitoring of structural prestress loss in RC beams by inner distributed Brillouin and fiber Bragg grating sensors on a single optical fiber. Structural Control and Health Monitoring, 2014, 21(3): 317-330.

[15] Kim J M, Kim C M, Choi S Y, Lee B Y. Enhanced strain measurement range of an FBG sensor embedded in seven-wire steel strands. Sensors (Basel, Switzerland), 2017, 17(7): 1654.

[16] Zhu W X, Qin H Y, Li J Z, Ou J P. Monitoring cable force of FAST project based on fiber Bragg grating sensor external installed on anchorage zone. Journal of Mechanical Engineering, 2017, 53(17): 23-30.

[17] Shiratsuchi T, Imai T. Development of fiber Bragg grating strain sensor with temperature compensation for measurement of cryogenic structures. Cryogenics, 2021, 113, 103233.

[18] Wang H P, Dai J G, Wang X Z. Improved temperature compensation of fiber Bragg grating-based sensors applied to structures under different loading conditions. Optical Fiber Technology, 2021, 63, 102506.

[19] Wang J F, Yu Y, Chen Y, Luo H, Meng Z. Research of a double fiber Bragg gratings vibration sensor with temperature and cross axis insensitive. Optik — International Journal for Light and Electron Optics, 2015, 126(7–8): 749-753.

[20] Iwashima T, Inoue A, Shigematsu M, Nishimura M, Hattori Y. Temperature compensation technique for fiber Bragg gratings using liquid crystalline polymer tubes. Electronics Letters, 1997, 33(5): 417-419.

[21] Wang Y S, Wang Z Q, Wang T, He D W. A novel temperature self-compensation FBG vibration sensor. Journal of Physics: Conference Series, 2011, 276(1): 012146.

[22] Liang M F. A fiber Bragg grating pressure sensor with temperature compensation based on diaphragm-cantilever structure. Optik, 2017, 145, 503-512.

[23] Huang Y, Li J, Kai G, Yuan S, Dong X. Temperature compensation package for fiber Bragg gratings. Microwave and Optical Technology Letters, 2003, 39(1): 70-72.

[24] Kaung Y, Guo Y X, Xiong L, Liu W L. Packaging and temperature compensation of fiber Bragg grating for strain sensing: a survey. Photonic Sensors, 2018, 8(4): 320-331.

[25] Qin H Y, Zhu W X, Zhang H L, Zhou Z, Ou J. Manufacturing and performance analysis of intelligent steel strand embedded with prepressure large scale fiber Bragg grating sensor. Chinese Journal of Lasers, 2017, 44(4): 0410001.

[26] Qin H Y, Shen Q X, Zhu W X, Zhang H L. Range-expansion technology and fatigue performance study on the self-sensing steel strand with an embedded fibre Bragg grating sensor. Strain, 2020, 56(5): e12354.

[27] H. Y. Qin, Q. X. Shen, J. P. Ou, and W. X. Zhu, “Long-term monitoring reliability and life prediction of fiber Bragg grating-based self-sensing steel strands,” Advances in Civil Engineering, 2020(2020): 7687039.

[28] Zhu W X, Shen Q X, Qin H Y. Research and application of FBG monitoring technology in internal prestressed steel strand. Acta Photonica Sinica, 2019, 48(2): 0206002.

[29] W. X. Zhu, Q. X. Shen, and H. Y. Qin, “Monitoring of prestress and bond stress of self-sensing FBG steel strand,” Measurement, 2021(177): 109246.

[30] Wu M C, Pater R H, DeHaven S L. Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors. Proceedings of SPIE — The International Society for Optics and Photonics, 2008, 6933, 28-37.

[31] Qin H Y, Wan W Q. Temperature characteristics of fiber Bragg grating strain sensor with groove embedded package. Railway Engineering, 2020, 60(9): 57-59.