Study on Strain Transfer of Substrate Encapsulation FBG Strain Sensor

摘要

The FBG sensors of measuring stress and strain on the surface of concrete are mainly based on substrate encapsulation in engineering. Since the substrate encapsulation FBG sensor has a multilayer structure, there is certain consumption when the stress is transferred from the surface of concrete to optical fiber, which leads to difference between measured value and actual value. This paper analyzes the influencing factors of strain transfer rate by the method of theoretical calculation and finite element analysis. The formula of strain transfer is thereby obtained.