Discrimination between the strain and temperature effects of a cantilever beam using one uniform FBG sensor

摘要

Many studies have been conducted on the simultaneous measurement of temperature and strain of different structures by fiber bragg grating (FBG) sensors for structural health monitoring purposes. However, most of them have used more than one FBG sensor to discriminate between temperature and strain. The present paper utilized the capability of one uniform FBG sensor for simultaneous measurement of strain and temperature in a cantilever beam. It is achieved by simultaneously monitoring the changes in the full width at half maximum (FWHM) and the Bragg wavelength shift of the optical spectrum of the FBG sensor in the proposed experimental setup. Besides, simulations of FBG spectra are performed for a more detailed study using the data achieved by nonlinear finite element analysis. The strain sensitivity of 0.78 and 0.84 pm/mu epsilon are obtained for the uniform FBGs used in the experiment and simulation. In addition, the results for the temperature sensitivity are achieved at 12 and 14.4 pm/degrees C, respectively. The experimental and simulation results for detecting FWHM variations and wavelength shifts due to applying strain and temperature were in good agreement with a 6.5 error.Fo6D