Theoretical principles and simulation analysis of an intelligent corrosion sensor based on fiber Bragg grating

Corrosion of reinforcing bars is a major factor affecting the durability of reinforced concrete structures. The volume of corroded reinforcement expands and the protective layer gradually cracks, which in turn reduces the serviceability of the structure. In this study, a fibre optic intelligent corrosion monitoring device based on magnetic sensing is investigated. A new type of magnetic probe is designed for sensing the corrosion of steel reinforcement, and strain sensing is carried out by utilizing high elasticity diaphragm and fibre optic grating structure. A finite element method is utilized to simulate the sensitivity and linearity of the device under different magnetic forces. The experimental results show that the sensor has good mechanical response effect and the fibre optic diaphragm stress sensing structure has good linearity, which can achieve long-term high-precision non-destructive monitoring of rebar corrosion.