Measurement accuracy of FBG used as surface-bonded strain sensor installed by adhesive

To accurately assess measurement precision and correct obtained strain, a new model, considering reinforcement effects on adhesive and measured object, is proposed in this study, which is verified to be accurate enough by numerical method. Meanwhile, a theoretical strain correction factor is obtained, which is demonstrated to be significantly sensitive to recoating material and bonding length as suggested by numerical and experimental results.

It is also concluded that short grating length as well as thin but large-area (preferably covering the whole FBG) adhesive can enhance the correction precision.