Research on the methodology of development and calibration of flexible encapsulated fiber Bragg grating sensors

Abstract

This study developed a type of flexible Fiber Bragg Grating (FBG) sensor and proposed appropriate calibration methods. Strain transfer theory-based calculations were utilized to estimate the optimal size of the FBG sensor. This methodology addressed the strain transfer issues and established correlations between the encapsulated material and optical fiber. As part of the calibration procedure for embedded FBG sensors, bending and temperature calibration tests were conducted. The calibration tests evaluated the correspondence between the center wavelength of the FBG sensors and the deformation and temperature, respectively. Formulas for sixteen FBG sensors which couple deformation and temperature fluctuations, were developed to calculate the cumulative deformation of asphalt specimens. The effectiveness of detecting deformation and the perception of the encapsulated FBG sensors were validated through laboratory rutting tests. Results demonstrated that the flexible encapsulated FBG sensors survived and performed effectively. This allowed for effective monitoring of the mechanical response of asphalt pavement.