Research on enhancement sensitivity of embedded fiber Bragg grating sensor

Abstract With its unique advantages, embedded fiber Bragg grating (FBG) sensor is more and more used in the field of engineering structural health monitoring. According to the actual needs of engineering monitoring, we combined with the internal structure to make sensitivity design of the sensor. It mainly through setting the elastic modulus and the radius of sensor's inner sheath intermediate section, to make the strain of middle section larger than average strain, In order to achieve the increasing sensitivity. Through the analysis, the enhancement degree is relevant to the length, radius and elastic modulus of the middle section, so it could achieved different requirement of sensitizing by adjusting these parameters. Through the analysis of the core strain in the sensitizing structure, it can obtain the strain transfer distribution in the scope of sensor. All these could provide the theory basis for the realization of embedded FBG sensor's sensitivity enhancement.