Abstract:In the course of pulsed eddy current testing, the incline of the probe or the roughness of the surface of the tested object will lead to the lift-off effects, which have a bad influence on the result of pulsed eddy current (PEC) nondestructive testing. Based on the analysis of the operating principle of PEC, two different simulation models with the excitation coils of columniform and rectangle structures are established by ANSYS finite element simulation software and the simulations on the specimen of ferromagnetic and non-ferromagnetic materials are done respectively. Through the analysis of the eddy current and rotated magnetic field, the influence effect of response signal with the variation of the lift-off distance and the reason is given. Finally, the results of simulation are verified by experiment methods. The results of the experimental work confirm the correctness of simulation, which will lay the foundation for the elimination of lift-off effects.