通过扰动磁场识别缺陷

,1),(,710049):,,:;;:TG115.28+4:A:100026656(2001)0220047204DEFECTRECOGNITIONBYPERTURBEDMAGNETICFIELDSUNXiao-yun,CHENDe-zhi1),SHENGJian-ni(XipanJiaotongUniversity,Xipan710049,China)Abstract:Theperturbedmagneticfieldduetoadefectgivesmoreinformationaboutthedefectthanthecoilimpedancechange.Therelationsbetweentheperturbedfieldanddefectparametersarestudied.Adefectcanbereconstructedbyperturbedfield.Keywords:Eddycurrenttesting;Defectrecognition;Fieldanalysis,,,,,(FA2ECT),[1],d=24.0mm,R=22.62MSm-1,1,f=1kHz,D=3.346mm,L,D,yOz;(xp,yp,0)11,[2],:1999210206:(98069821)1)1r1=2.510.01mmr2=7.380.01mml2-l1=4.990.01mmn=4000l1=0.300.01mmI=1.0ö4000A,,,,Bz,Bz[2],,,pp,Bz[2]7423220012NDTVol.23No.2Feb.2001©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.Bz(r)=-jXL0S0pHzx(r,r)dS(r)(1)Xr(x,y,z)r(x,y,z)S0Hzxxz[2]Hzx=jsinU4PX02K2K+ueuz-KzJ1(KQ)dK(2)Q=(x-x)2+(y-y)2sinU=y-yQJ1()1u=K2-k2,,z0,z0S0yOz,(2),Bz,Bz22.12,Bz,(a)(b)2()(2a),,,,,Bz,(180),,(2b),,,,2;3a(a)Bz(4,6,8,10,12,14,16,18,22,26,32mm;,,y0)(b)Bz(,;12mm,)(c)Bz(8mm,yp=7mm)3Bz(4mm,,0.25mm,,)84:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.Bz();3bBz;3cBz;,Bz,Bz,,Bz(3a32mm),(),,(x),Bz4,Bz,Bz,(2)sinU,4xBz(,x0,1,2,3,4,5mm;16mm,8mm;)2.2DBz,Bz(5)D,Bz;DD,Bz,D3D,Bz,2D5b2.3,,(6)2.4(a)DBz(,D1,2,3,4,5,6,7mm)(b)DBz(y=8mm,)5Bz(16mm,)6Bz(4mm,16mm),,7CAB,,,,,94:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.7Bz(4mm,4mm)2.5,Bz83,,,$Z,(FA2ECT)[1],:(a)(b)8(4mm;14mm,212mm;124mm;yp=0mm)[1],,,.[J].,1999,21(6):241-244.[2],,,.[J].,2000,22(3):99-105.[3].[D].:,1998.2001UT,RT,MT,PTET(Ê)(É):2001312():100:UT,RT,ET20;MT,PT15():UT,RT,ET1200ö;MT,PT1000ö:,,,,,():100:200437::[phone]:[phone]:2001(Ë),05:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.