Experimental Study On Magnetic Flux Leakage Signals Analysis And Defect Evaluation

Magnetic flux leakage testing technology is based on magnetic flux leakage testingsignals analysis and evaluation to get samples of the damage. Under normal circumstances,useful information of detection may hiding among the detection signal, mining thecharacteristics and analysis of the detected signal is the key to get more test information,starting a study of magnetic flux leakage signals analysis and defect evaluation is of greatsignifucance.In response to the situation that the typical MFL testing signals of tangential and normalcomponents have been being used in the evaluations for defects, raises questions for a doubt,if ’’nipple peak’’and ’’sunken peak’’in the MFLppare all the contribution source of defectmagnetic field, I.e., whether the MFLpp is able to truly and accurately represent or reflect thesize of magnetic flux leakage response defect information. In this regard, of the existing twoclassic signs in particular, known as "peak" signal to the tangential component of "negativeside-lobe" features of contribution into the analysis of MFL. With the "flux" and "magneticflow hole" dynamic analysis of the T-MFL in terms of signal "concave peak" characteristicessentially by "magnetic flow hole" has nothing to do with real defects caused by MFL Andthrough further exploration and analysis of the signal，MFL signal characteristic, detectionstatus information and associated linearity are guidelines, presents a defect assessmentmethod which is based on multiple eigenvalues of MFL signa.Then, to the above questions, demonstrated and further explore the methods andmechanisms analysis by building a multi-air modeling by finite element method:find lift-off"magnetic holes" variation by defects on spatial magnetic cloud. Multiple MFL signaleigenvalues: MFLpp, MFLp0, Ss, Sdand Stetc. were obtained by extracting values, fromwhich we got MFL signal characteristic value with better related linearity with defectinformation and detection status information, so that we can replace the existing single peak-peak evaluation methods.Develop a multi-dimensional platform of experimental scan, the device can carry treatsMFL components tested implementation of automatic scan for uniform and MFL components detection of status parameters are precisely adjustable. Through the production of automaticmagnetic flux leakage testing platform to verify the theoretical analysis and simulationanalysis. Scale decreasing MFL method for experiment can effectively save the space,enhance experimental efficiency and get many types of artificial defects signal in real testing.Experimental results are consistent by calculation and generalization of MFLpp, MFLp0, Ss,Sdand St, get further evidence of the limitations of MFLpp-evaluation system.