Strain transferring mechanism analysis of the surface-bonded FBG sensor.

The mechanical analysis model of surface-bonded fiber Bragg grating (FBG) shear strain transfer is established in consideration of the linear viscoelastic effect of the adhesive layer, which is simplified as a standard linear solid model. And the strain transfer relation is acquired and validated by anchor bar uniaxial tension experiments. There is good correspondence between calculated values and experimental results. Finally, the influences of shear modulus, length and width of the adhesive layer, and thickness of the interlayer on the instantaneous and quasistatic strain transfer are analyzed by numerical simulation.