模态声发射基本理论

,1),2)(,100076):(AE),:;;;:TG115.28:A:100026656(2002)0720302205ASTUDYONMODALACOUSTICEMISSIONTHEORYGENGRong2sheng,SHENGong2tian1),LIUShi2feng2)(BeijingAeronauticalTechnologyResearchCentre,Beijing100076,China)Abstract:Descriptionhasbeenmadeofthebasictheoryofmodalacousticemission(MAE)forthinplateanditsap2plicationprospectiveforengineering.Keywords:Acousticemissiontesting;Modalacousticemission;Waveformanalysis;Signalprocessing(Lamb)[1,2],,AE,(),,(),,2.5mm,S0(),(),A0(),,,,S0,30800kHz[3]AE,AE,,,:20022042081),1000132),1000841991,Gorman[4],Lamb(PWAE)(MAE),AE,AE1,AE,,()1,,(Lamb)x,z(z=-bz=+b),,,y,120324720027NDTVol.24No.7July2002©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.(1)525x2+525z2+k2l=0525x2+525z2+k2t=0(1)kl,ktVV=grad+rotej(kx-t),x[1,2]F(,,k)=tgbtgb+4k2(k2-2)21=0(2)+1,-12=2c2l-k22=2c2t-k2(3)kk=cccl,ctLambc(cg)2(2)(2)[1],(),cecr,cfcr(cr)x=1,21,S0A0,[1,2],2,AE,,AE,,,10mm,(),221,,S0A0,,,,(a)(b)22,h=2b,[5]D2-P=0(4)DD=Eh312(1-2)PE,P()hh525t2+Eh312(1-2)2=0(5)525t2+Eh212(1-2)2=0(6)=0exp[j(kx-t)],0=d2dx2303:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,(-2)+Ak4=0A=Dh2=h2Ek412(1-2)(7)c=/k,c=h2E12(1-2)14=E12(1-2)14h(8)cgcg=55k=h2E3(1-2)k=4E3(1-2)14h=2c(9)(9),,,,,xyxAEAE,E52ux5t2=11-252ux5x2+12(1+)52ux5y2+12(1-)52uy5x5y(10)E52uy5t2=11-252uy5y2+12(1+)52uy5x2+12(1-)52ux5x5y(11),52ux5t2=E(1-2)52ux5x2(12)52uy5t2=E2(1+)52uy5x2(13),xcext=E(1-2)(14)x()ct=E2(1+)(15)ct=1-212cextct=0.20.4,,x0.6,SHSV,,Dunegan,SH(IP),(OOP),,100kHz[6,7],SH,,,SH(14)(8),,S0A0,,,,,,,,,,A0,,AE3[5]3,,,,(8),,3,()MAE,,()3()AE403:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,,,,680mm400mm12.5mm(4),320mm(180mm)4AE,,12,1,(5),,(6)51320mm,5958s,,v=5520m/s,5700m/s,AEAE,,(),,,AE62,AE,,,MAE[8]3,,,,,f(x,t)=F(x)ejt,,h525t2+D2=F(x)ejt(16),,,(16),,h525t2+Eh312(1-2)2=0(17)(x,t)=0(x)ejt(x,t)=0e-j2hD14ejt(18)(19)Dd4dx4dx=F503:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.0=F4D1(2h)34=F12(1-2)E141hh(19),Medick,h[9]4,,,(S0)(A0)(SH)(IP),(OOP),,,AEAE,:[1]VictorovIA.RayleighandLambWaves[M].NewYork:PlenumPress,1967.[2].[J].,1999,21(9):409-413.[3]JeongHD,ShinHJ,RoseJL.Detectionofdefectsinathinsteelplateusingultrasonicguidedwave[A].Pro2ceedingsof15thWCNDT[M/CD].Rome,Italy:2000.020.[4]GormanMR.Platewaveacousticemission[J].JASA,1991,90(1):358-364.[5],EM.(3)[M].:,1962.[6]DuneganHL.Modalanalysisofacousticemissionsignals[J].JournalofAcousticEmission,1998,15:1-4.[7]DuneganHL.Useofplatewaveanalysisinacousticemis2siontestingtodetectandmeasurecrackgrowthinnoisyenvironments[A].ProceedingsofStructuralMaterialsTechnologyAnNDTConference[C].SanDiegoCalifornia:1996.[8].[J].,1999,24(4):367-372.[9]MedickMA.Ontheclassicalplatetheoryandwaveprop2agation[J].ASMEJournalofAppliedMechanics,1961,28:223-228.(301)12()+(),()()()(3)737777(BAC),,Gould2Bass,3,(),,,,:[1],.[M].:,1994.80-110,224-227.[2]BS6072-1981,[S].[3]MIL2HDBK2333(USAF)1974,[S].,.1986.15.603:©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.