1、南昌航空工业学院硕士学位论文基于铁磁材料力－磁效应的磁记忆方法检测机理的基础性研究姓名：王东升申请学位级别：硕士专业：测试计量技术及仪器指导教师：任吉林20060101南昌航空工业学院硕士论文ABSTRACTThe thesisisaimed at the magnetic memorymethod thatisone new nondestructive inspectionmethod and characterized bypriorinspection.Based onthe magnetophysicstheory
2、,and byexperimentsand finite element method,the influencesofstressonmagnetic fluxleakage(MFL)offerromagnetic materialswere studied,the mechanismofmagnetic memorymethod were alsodiscussed. During the experiments,a scanning device withhighorderaccuracy(planar 2D posi
3、tioning)wasdesigned to help realize exactlypositioning measurementofMFLofspecimens.The driving circuitofscanning device wasdesigned.Tongswerealso designed tofix the probe ofGauss meter onthe scanning device.Forthe convenience oftesting,sampling software wasprogramm
4、ed using VC++6.0 throughcomputer.Thissoftware cancontrolthe scanning deviceto move invariousways,and cantakerealtime data fromGaussmeter byRS232.Now,weakmagnetic measurement systemhasbeencompleted. Tensile loading experimentsof0.20%Cand 0.45%C(allmassfraction)steel
5、 were conducted inthe experiments.The MFLdistributionsofspecimensunder uniaxial tensionloading conditionand after removalofapplied uniaxialtensionat differentloadingswere testedbythe weak magnetic measurementsystem.Atthe same time,simulationsofstressofloaded specim
6、enswere carried outbyfinite elementmethod.Thena contrast wastakenbetweenthe resultsofmagnetic measurementand stresssimulation.Itshowsthatat the stressconcentrationzone,changesofMFLwere relativelyweak withslightdeformationofthe specimens.With the deforming to plasti
7、c and further the changing ofMFLexhibitsmore distinct,and whennecking emerging a veryintensive change takesplace.Itisindicated that magnetic memory effectisrelated to the microstructure ofthe material.The changesofMFLswere mainlyinduced bymagnetoelasticeffectwitha
