Application of temperature compensation fiber Bragg grating pressure sensor for bolting quality monitoring

For the purpose of improving the existing Fiber Bragg grating pressure sensors’ cross-sensitivity of strain and temperature,a novel type of FBG pressure sensors with temperature compensation was developed based on the fun- damental principles of FBG and elastic diaphragm structure. The mechanical deformation model of diaphragm structure was established and the mathematical relationship between the FBG center wave length drift and pressure as well. Al- so,the influence of diaphragm’s material and dimensions on the sensitivity was numerically analyzed using Matlab, and additionally the numerical simulation of the deformation characteristics of the diaphragm was conducted with finite element software ABAQUS. The theoretical value of the sensors’ pressure sensitive value is 40. 43 pm / MPa,35. 6 pm /MPa by calibration test and 37. 62 pm / MPa with temperature compensation. The performance test indicated that this sensor had a good linearity,low frequency chirp and high stability. The application results show the feasibility of fiber Bragg grating sensing technology in coal mine monitoring and suitable for the further popularization and application.