Research on Characteristics of Eddy Current Probe Based on Finite Element Simulation

Eddy current testing plays an important role in nondestructive testing technology fields such as industrial production and equipment operation and maintenance. This article introduces an eddy current probe for non-destructive testing, which consists of an excitation coil and two receiving coils. Under the excitation of voltage signals, the excitation coil generates induced eddy currents in the specimen. The eddy currents in the specimen change with the defects, and the receiving coil captures the changes in the magnetic field generated by the eddy currents to distinguish surface defects in the specimen. Theoretical analysis was conducted on the excitation coil and receiving coil of the eddy current probe, and the finite element simulation software Maxwell was used to model and simulate the sensor. Using numerical methods to analyze the working mode of the probe under sine wave voltage excitation, the surface eddy current distribution and probe output characteristics of Q235 specimens. The influence of eddy current effect on the output of Q235 material probe was simulated and analyzed. The influence of different defect depths on the output voltage of the probe in Q235 specimens was analyzed. Based on the simulation results, a physical probe was made, and the output signals of the probe at different defect depths were obtained. The effectiveness of the probe for defect detection was verified through experiments.