Study on Strain Transfer Characteristics of Fiber Bragg Grating Sensors

In this article, strain transfer characteristics of fiber Bragg grating (FBG) sensors is analyzed with finite element method axial strain distribution of each layer described, and influencing factors of the strain transfer obtained, including bonded length of the sensor, thickness as well as Young's modulus of the adhesive. The calculation results are verified by tensile tests of metal specimens. The results reveal that at suitable bonding conditions, the FBG sensors have good sensing characteristics. In addition, it is also easy for the chirping phenomenon to occur if the bonded length is not sufficient. The strain transfer efficiency can be improved and the chirping phenomenon reduced by either increasing the bonded length or decreasing the grating length or thickness of the adhesive, or choosing the proper adhesive.