Simulation Calculation And Analysis Based On Remote Field Eddy In Ferromagnetic Pipeline

Transmission pipeline of Petrochemical and electric power departments is the artery of the national industrial system, the detection of the industrial pipeline has the significant economic value. But some of the pipeline detection methods exists various problems in some degree. The remote-filed eddy current (RFEC) inspection technique is an important branch of eddy current nondestructive testing (NDT) technique, and is one of newly developed technique which is used in tube nondestructive testing. The remote-filed eddy current inspection technique has many advantages as the same inspection sensitivity for the internal and external defects in the tube wall, also the lifting-off and environment have little effect on it, now it plays an more and more important role in the testing and repairing of pipes and tubes.This paper elaborates development condition of RFEC technique,the principle analysis,electromagnetic calculation of the finite element analysis method and ANSYS simulation software, creating 2D and 3D RFEC models by parametric design language and proceeds the simulation studies. The basic character of the remote filed eddy current is simulated and analyzed in case of two dimension axial symmetry ideal situation which observes the remote filed eddy current basic phenomenon; the full circumferential defect model is investigated to approve the feasibility of using the RFEC techniques to detect the position,width and depth of defect, and draw the conclusion that RFEC has high sensitivity to test defect in depth than the width. The pit corrosion, crack non-axisymmetry defects models are simulated and summaries the corresponding phase difference change of defects under the different shapes width and depth by methods of extracting detector coil voltage values. Meanwhile, the paper further researches the RFEC 3D probe on reconstruction of the defect position.This subject does some simulation study on the mechanism of remote-filed eddy current testing; the influence factors and the characteristics of defect signals by using ANSYS finite element analysis software, then draw the regular pattern of corresponding signal. And these conclusions provide theoretical support for remote-filed eddy current technique in the pipeline detection application and some guiding roles for the remote-filed eddy current detection system.