As an important strain transfer part to FBG

material characteristics of bond layer directly affect the measurement accuracy of FBG strain sensors. According to the bond layer strain transfer model and the formula of strain transfer coefficient K

under the premise of determining the structure size parameters

simulate the impact on strain transfer coefficient K by elastic modulus of bond layer materials

the results show that strain transfer efficiency of metal is superior obviously to organic adhesive.The contrast test has been carried out

the test results indicate that the Pb’s strain transfer coefficient K maintains the level of 0.98 while epoxy’s maintains about 0.90

Pb’s transfer efficiency increases by 8.9%.to epoxy. Replacing epoxy.with Pb can greatly improve the strain measurement precision

and can more fully exert fiber optic sensors’ excellent strain measurement ability.