Simple configuration of a fiber optic sensor for measuring deflection in concrete beams

• Published in: IEEE sensors journal Vol. 23; no. 7; p. 1
• Main Authors: Camas-Anzueto, J.L., Juan-Jimenez, A.M., Anzueto-Sanchez, G., Perez-Patricio, M., Grajales-Coutino, R., Hernandez-Gutierrez, C.A., Alonso-Farrera, F.A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Configurations; Deflection; deflection measurement; Diameters; Enter Optical fiber sensors; Fiber optics; Grooves; Laboratory tests; Mathematical analysis; Monitoring; Optical fiber cables; Optical fiber networks; Optical fiber sensors; Optical fibers; Optical variables measurement; Pulleys; Sensitivity; Sensors
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2023.3242584

This work proposes a simple configuration of a fiber optic sensor used to measure deflection in concrete beams. This fiber optic sensor includes pulleys with a groove to generate a constant drastic loss in the optical fiber. The fiber optic sensor was characterized as a function of three pulley diameters in a home-made metallic base. The fiber optic sensor used a multimode optical fiber since it demonstrated better behavior than a single-mode fiber, and the deflection caused a loss in the optical fiber. This loss was found to be the parameter related to concrete beam deflection. In this way, we carried out characterization to find the best sensitivity. The sensitivity calculated in the lab tests using a multimode fiber in the proposed fiber optic sensor with three pulleys of 1.2 cm in diameter was -0.34785 dB/cm. Furthermore, the proposed fiber optic sensor was validated in a concrete beam in real-time using a 50 tons variable load actuator. Finally, the fiber optic sensor installed in a concrete beam presented a dependency as a function of overload in tons. The sensitivity obtained in the test was -0.02932 dB/cm.