Reliability Evaluation of Fiber Optic Sensors Exposed to Cyclic Thermal Load

Title & Authors
Reliability Evaluation of Fiber Optic Sensors Exposed to Cyclic Thermal Load
Kim, Heon-Young; Kang, Donghoon; Kim, Dae-Hyun;

Abstract
Fiber Bragg grating (FBG) sensors are currently the most prevalent sensors because of their unique advantages such as ease of multiplexing and capability of performing absolute measurements. They are applied to various structures for structural health monitoring (SHM). The signal characteristics of FBG sensors under thermal loading should be investigated to enhance the reliability of these sensors, because they are exposed to certain cyclic thermal loads due to temperature changes resulting from change of seasons, when they are applied to structures for SHM. In this study, tests on specimens are conducted in a thermal chamber with temperature changes from -$\small{20^{\circ}C}$ to $\small{60^{\circ}C}$ for 300 cycles. For the specimens, two types of base materials and adhesives that are normally used in the manufacture of packaged FBG sensors are selected. From the test results, it is confirmed that the FBG sensors undergo some degree of compressive strain under cyclic thermal load; this can lead to measurement errors. Hence, a pre-calibration is necessary before applying these sensors to structures for long-term SHM.
Keywords
Structural Health Monitoring (SHM);Fiber Optic Sensor (FOS);Fiber Bragg Grating (FBG);Cyclic Thermal Load;
Language
Korean
Cited by
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