Research on fatigue crack quantitative monitoring based on eddy current sensor with an interactive induction coil layout

To reduce the number of sensor channels, this paper proposes an eddy current sensor with an interactive induction coil layout. First, the crack monitoring principle of the sensor is analyzed, and fatigue crack monitoring experiment is carried out. It is found that the cracks can be quantified according to the characteristic points of the sensitivity variation curve. Then, a permalloy plate is used for reinforcing the sensor, and the crack monitoring accuracy test is carried out, which shows that the crack monitoring accuracy error of the sensor is no more than 0.1 mm. Finally, the sensor network is built by the sensor according to the dangerous parts of the butt joint structure determined by the finite element analysis. And fatigue crack monitoring experiment is carried out, which shows that the sensor network can determine the position and length of the fatigue crack, and the error is no more than 0.1 mm.