文献翻译-一种电磁探伤无损检测方面实际的传感器超材料

英文翻译附录一外文原稿：AKindofPotentialPracticalSensorsofMetamaterialinElectromagneticFlawNondestructiveTestingAbstract：Wepresentanewkindofmethodofelectromagneticflawnondestructivetestingwithcoatingofmetamaterialsandsimulationnearelectromagneticfieldpropertyfortestcrack.ThesimulationofimprovingaNondestructivetesting(NDT)probeelectromagneticradiantpropertybyMetamatrials(MMs)coveringatinycurrentelementisinvestigatedandanalyzedusingAnsoftHFSSbasedonfiniteelementmethod(FEM),whichpermittivityandpermeabilityarenegative.Electromagneticmodel:IdealMMsballshellwithinnerradiusof1mmandouterradiusvariation,andtheshellsrelativepermittivityandrelativepermeabilityareall3.0,dielectriclosstangentandmagneticlosstangentareall0.1;andexcitingcurrentelementlengthiswith0.3mm,diameter0.2mm,value1mAatfrequency10GHz;andsimulationiswithradiationboundaryconditions.Thesimulatingnearelectromagneticfieldvarietywithratioofinnerradiusandoutradius,andsonearorlocalfieldofMMssensoronasurfacecrack,aswellascomparingnearfieldvalueofsensorwithcoatingcommonmaterialarefinished.ResultscanbeseenthatMMsfilmsensornearelectromagneticfieldandradiationpropertiesareobviouslybetterthanothertwokindsofstructureswithoutcoatingmediumandcoatingwithcommonmedium,andMetamaterialmaybeopenedoutsomenewkindsofsensorsinelectromagneticflawnondestructivetestingforpotentialpracticalapplicationsinfuture.Keywords:Metamaterial,Nondestructive,Flaw,AnsoftHFSSSoftware,Sensor1.IntroductionIn1967,Veselagotheoreticallyconsideredahomogeneousisotropicelectromagneticmaterialinwhichbothpermittivityandpermeabilitywereassumedtohavenegativerealvalues.SincetheE,HfieldsandthewavevectorkofapropagatingplaneEMwaveformaleft-handedsysteminthesematerials,Veselagoreferredtothemas“left-handed”media,ormetamaterialmedia1-3.Insuchamedium,heconcluded,thedirectionofthePoyntingvectorofamonochromaticplanewaveisoppositetothatofitsphasevelocity.Itsuggeststhatthisisotropicmediumsupportsbackward-wavepropagationanditsrefractiveindexcanberegardednegative.Sincethesematerialswerenotavailableuntilrecently,theinterestingconceptofnegativerefraction,anditsvariouselectromagneticandopticalconsequences,suggestedbyVeselago,hadreceivedlittleattention.ThiswasuntilSmithetal.4,inspiredbytheworkofPendryetal.3,5constructedacomposite“medium”inthemicrowaveregimebyarrangingperiodicarraysofsmallmetallicwiresandsplit-ringresonators4,6-9anddemonstratedtheanomalousrefractionattheboundaryofthismedium,whichistheresultofnegativerefractioninthisartificialmedium8.Metamaterialsarebroadlydefinedasartificialeffectivelyhomogeneouselectromagneticstructureswithunusualpropertiesnotreadilyavailableinnature.Thisopenedthefieldofcompositematerialsormetamaterialsformicrowavesandopticalapplications.SincetheideaproposedbyVictorVeselagoin1968,theavailabilityofsuchamaterialistakenupnowadaysandextended10-21.Inthispaper,wepresentanewkindofsensorofelectromagneticflawnondestructivetestingwithcoatingofmetamaterialandthenapplyittosimulatenearelectromagneticfieldpropertyfortestcrack.Ouraimistofindoutsomeapplicationofmetamaterialcoveringinsensorthroughbetterfielddesign,andthismethodcangreatlyimprovethenearelectromagneticfieldandradiationpropertiesofthetransducer.2.SplitRingResonators(SRRs)Doublesplitringresonator(SRR)isacommonkindofmetamaterialcell,andconductivestructureinwhichthecapacitancebetweenthetworingsbalancesitsinductance,Figure1.Atime-varyingmagneticfieldappliedperpendiculartotheringssurfaceinducescurrentswhichindependenceontheresonantpropertiesofthestructure,produceamagneticfieldthatmayeitheropposeorenhancetheincidentfield,thusresultinginpositiveornegativeeffective.Foracirculardoublesplitringresonatorinvacuumandwithanegligiblethickness,thefollowingapproximateexpressionisvalid22:where,aistheunitcelllength,andiselectricalconductance.Itbecomesnegativefor0mpm,where0mistheresonantfrequency(forwhicheff);pmisthemagneticplasmafrequency(forwhicheff0).Usually,thereisanarrowfrequencyrangewheretheeff0.Thinmetallicwiresweredescribedasoneoftheearlieststructureswithnegativepermittivity,andthemediawiththeembeddedthinmetallicwirescanbeasartificialdielectricsformicrowaveapplications,Figure2.Thestructurewith0describedbyPendryconsistsofasquarematrixofinfinitelylongparallelthinmetalwiresembeddedindielectricmedium.Inthesituation,themediumisairorvacuum,andtheradiusofasinglewireisverythinnerthanthedistancebetweentwowires,thatisra,theeffectivedielectricpermittivitycanbewrittenasfollow23:where,pistheplasmafrequencyforthelongitudinalplasmamode.Clearly,itbecomesnegativeforp.3.MetamaterialSensorSimulationSimulationofimprovingtheNondestructivetesting(NDT)transducerelectromagneticradiantpropertybyMetamatrials(MMs)coveringatinycurrentelementisinvestigatedandanalyzedusingAnsoftHFSSbasedonfiniteelementmethod(FEM),whichpermittivityandrelativepermeabilityarenegative.3.1.ElectromagneticModelandAssigningMaterialsTheidealMMsballshellfilmiswithinnerradiusof1mmandouterradiusvariation,andtheshellsrelativepermittivityandrelativepermeabilityareall3.0,dielosstangentandmagneticlosstangentareall.SelectingtheSolutionTypeChoosetheDrivenModalsolutiontypewhenwewantHFSStocalculatethemodal-basedS-parametersofpassive,high-frequencystructuressuchasmicrostrips,waveguides,sensors,andtransmissionlines.TheS-matrixsolutionswillbeexpressedintermsoftheincidentandreflectedpowersofwaveguidemodes.3.3.AssigningBoundariesAssigningBoundariesandAssigningExcitationsForDrivenModal,aradiationboundaryisusedtosimulateanopenproblemthatallowswavestoradiateinfinitelyfarintospace,suchasantennadesigns.HFSSabsorbsthewaveattheradiationboundary,essentiallyballooningtheboundaryinfinitelyfarawayfromthestructure.Aradiationsurfacedoesnothavetobespherecal,butitmustbeexposedtothebackground,convexwithregardtotheradiationsource,andlocatedatleastaquarterwavelengthsfromtheradiatingsource.Insomecasestheradiationboundarymaybelocatedcloserthanone-quarterwavelength,suchasportionsoftheradiationboundarywherelittleradiatedenergyisexpected.Here,simulationiswithradiationboFigure3.ExcitationsinHFSSareusedtospecifythesourcesofelectromagneticfieldsandcharges,currents,orvoltagesonobjectsorsurfacesinthedesign.WemayassignthecurrentsourceofexcitationstoaDrivenModalsolutiontypeHFSSdesign,andexcitingcurrentelementlengthiswith0.3mm,diameter0.2mm,value1mAatfrequencyof10GHz.4.RunningSimulationsandConclusionsAfterspecifyhowHFSSistocomputethesolution,webeginthesolutionprocess.Adaptivesolution,maximumnumberof15,andmaximumdeltaenergy0.08areselectedforsolutionsetup,wegetsomeresultsasfollowing:ForthreekindsofstatesofasensorwithcoatingMMs,thosearecoatingcommonmediumandwithoutcoating,simulatingnearelectromagneticfieldvarietywithratioofinnerradiusandoutradius,seeFigure4.Nearfieldisthatoneitsdistancelessthan20mmfromexcitingsourcepoint.SupposetestanaluminumworkpiecewithsurfacecrackbytheMMssensorwithr1/r2=0.5,cracklength6mm,width1mm,anddepth0.1mm,thenearfieldaroundcrackflawseeFigure5;andcomparingtonearfieldvalueofprobewithcoatingcommonmaterialseeFigure6.ResultscanbeseenfromFigure4thatforMMsfilmsensor,nearelectromagneticfieldpropertyisobviouslybetterthanothertwokindsofstructureswithoutcoatingmediumandcoatingwithcommonmedium,andnearfieldvalueisvarietyofratioinnerradiusandoutradius.Whenr1/r2=0.5andnoload,nearandlocalfieldofMMssensorcanreachto10dB,butonly21dBforsensorwithcoatingcommonmedium,and22dBforsensorwithoutcoatinganymedium.WegetfromFigure6thatnearfieldofaMMssensorishigherabout30dBthanoneoftransducercoatingcommonmediumwhenr1/r2=0.5andwithload.Similarly,radiationpowerofMMssensorcanreachto53dB,butonly74dBforsensorwithcoatingcom-monmedium,and75dBforsensorwithoutcoatinganymedium.MMssensorishigherabout20dBthanoneoftransducercoatingcommonmedium.Nearfieldandra-diationpowerarebothimportantpropertiesofasensor.Fromaboveresults,weknowthatMMsfilmsensorisexcellentfornearelectromagneticfieldandradiationproperties.Sosomemetamaterialnondestructiveelectromagneticsensorsincludingsoundwavetransducermaybeopenedoutforpotentialpracticalapplicationsinfuture.5.References1V.G.Veselago,“TheElectrodynamicsofSubstanceswithSimultaneouslyNegativeValuesofand,”SovietPhys2V.G.Veselago,“TheElectrodynamicsofSubstanceswithSimultaneouslyNegativeValuesofand,”UspekhiFizicheskikhNauk,Vol.92,1967,pp.517-526.3J.B.Pendry,A.J.Holden,D.J.Robbins,etal.,“Low-FrequencyPlasmonsinThinWireStructures,”JournalofPhysicsCondensedMatter,Vol.10,No.22,1998,pp.4785-4809.4D.R.Smith,W.J.Padilla,D.C.Vier,etal.,“CompositeMediumwithSimultaneouslyNegativePermeabilityandPermittivity,”PhysicalReviewLetters,Vol.84,No.18,May2000,pp.4184-4187.5J.B.Pendry,A.J.Holden,D.J.Robbins,etal.,“MagnetismfromConductorsandEnhancedNonlinearPhenomena,”IEEETransactionsonMicrowaveTheoryandTechniques,Vol.47,No.11,1999,pp.2075-2081.6D.R.SmithandN.Kroll,“NegativeRefractiveIndexinLeft-HandedMaterials,”PhysicalReviewLetters,Vol.85,No.14,2000,pp.2933-2936.7R.A.Shelby,D.R.Smith,S.C.Nemat-Nasser,etal.,“MicrowaveTransmissionthroughaTwo-Dimensional,Isotropic,Left-HandedMetamaterial,”AppliedPhysicsLetters,Vol.78,No.4,2001,pp.489-491.8A.Shelby,D.R.SmithandS.Schultz,“ExperimentalVerificationofaNegativeIndexofRefraction,”Science,Vol.292,No.5514,2001,pp.77-79.9N.EnghetaandR.W.Ziolkowski,“APositiveFutureforDouble-NegativeMetamaterials,”IEEETransactionsonMicrowaveTheoryandTechniques,Vol.53,No.4,2005,pp.1535-1556.10S.Enoch,G.Tayeb,P.Sabouroux,N.Guerin,etal.,“AMetamaterialforDirectiveEmission,”PhysicalReviewLetters,Vol.89,No.21,2002,ArticleID:213902.11B.Li,B.WuandC.-H.Liang,“StudyonHignGainCircularWaveguideArrayAntennawithMetamaterialStructure,”ProgressinElectromagneticsResearch,Vol.60,2006,pp.207-219.12A.-K.Hamid,“AxiallySlottedAntennaonaCircularorEllipticCylinderCoatedwithMetamaterials,”ProgressinElectromagneticsResearch,Vol.51,2005,pp.329-icsUspekhi,Vol.10,No.4,1968,pp.509-514.341.13J.BPendry,A.J.Holden,W.J.Stewart,etal.,“ExtremelyLowFrequencyPlasmonsinMetallicMicrostructures,”PhysicalReviewLetters,Vol.76,No.25,1996,pp.4773-4776.14C.G.Parazzoli,R.B.Greegor,J.A.Nielsen,etal.,“PerformanceofaNegativeIndexofRefractionLens,”PhysicalReviewLetters,Vol.84,No.17,2004,pp.3232-3234.15J.B.PendryandD.R.Smith,“ReversingLightwithNegativeRefraction,”PhysicsToday,Vol.57,No.6,2004,pp.37-43.16Z.X.XuandW.G.Lin,“ControllableAbsorbingStructureofMetamaterialatMicrowave,”ProgressinElectromagneticsResearch,Vol.69,2007,pp.117-125.一种电磁探伤无损检测方面实际的传感器超材料摘要：我们提出了一种新的电磁无损检测方法，通过超材料涂层和仿真靠近电磁场属性来检测裂纹。覆盖细小的电流元素的超材料（MMS）来提高无损检测（NDT）探头的电磁辐射属性的仿真，使用基于有限元法（FEM）中的AnsoftHFSS调查和分析，它的负介电常数和磁导率是负的。电磁模型：理想的MMs球壳内径是1毫米，外径是变化的，和壳的相对介电常数和相对磁导率都是-3.0，介电损耗角正切值和磁损耗角正切值都是0.1，并且与涂层为普通材料做的球传感器的近领域的值相比较，当频率为10GHz时，该模型的励磁电流元长度是0.3毫米，其直径为0.2毫米，值为1毫安。电磁场附近的各种内半径和外半径的比率的仿真，和MMs传感器表面上的裂纹如此接近或本区域，相对于带涂层的普通材料的传感器附近区域的值是完成的。结果很明显：MMs薄膜传感器近电磁场和辐射特性明显优于无涂层的介质和涂层与普通介质这两种结构传感器，在将来，超材料将打开一些新的各种传感器在电磁缺陷无损检测方面的潜在的实际应用。关键词：超材料，无损探伤，缺陷，AnsoftHFSS软件，传感器1介绍在1967年，韦谢拉戈理论上认为一个均匀各向同性电磁材料的介电常数和磁导率被假定为具有负实值。自从在这些材料中E，H场和波矢k传播的平面电磁波形成一个左手系统以来，韦谢拉戈称他们为“左撇子”的介质或超材料介质1-3。他的结论是，在这样的介质中，一个单色平面波的坡印廷矢量的方向与它的相位速度是相反的。它表明，这个各向同性介质支持的向后波的传播，它的折射率可视为负。由于这些材料是不可用的，直到最近，这个有趣的概念负折射，和它的各种电磁和光学结论才得到关注，韦谢拉戈说到。这是直到Smith等人4，受到彭德里等人工作的启发3,5，在微波体系中通过整理小金属导线和开口环谐振器4,6-9周向阵列构建了一个复合的“介质”，并陈述了此介质的边界处的异常折射，这是在该人工介质的负折射的结果8。超材料被广泛定义为人工有效均匀的电磁结构，在自然界其不同寻常的特性是无法找到的。这打开了复合材料或微波和光学应用的超材料领域。自从韦谢拉戈1968年提出的想法以来，这种材料的可用性从现在开始并扩大10-21。在本文中，我们提出了一种新的带涂层的超材料电磁探伤无损检测传感器，然后将它应用到靠近电磁场附近的裂纹检测。我们的目的是通过更好的现场设计找出传感器方面的一些超材料覆盖的应用，这种方法可以大大提高传感器近磁场和辐射特性。2开口谐振环（谐振环）双开口谐振环（SRR）是一种常见的超材料电池，如图1所示，导电结构，其中两环之间的电容平衡其电感，。一种随时间变化的磁场垂直于环表面诱导电流，该电流依赖于结构的共振特性，产生既可以减少也可以增强入射场的磁场，从而导致在正或负的有效值。对于一个在真空中和厚度可以忽略不计的圆形双开口环谐振器，下面的近似式是适用的22：其中，a是单位导体的长度，是电导。它变成负有0mpm，其中0m谐振频率（当eff）;pm的是磁场的等离子体频率（当eff0）。一般，有一个eff0窄的频率范围。薄金属线是具有负的介电常数的最早的结构之一，并与嵌入的细金属线的介质可以作为人工电介质微波应用，如图2所示。彭德里所描述0的结构由嵌入在电介质中的无限长的平行细金属线的正方形矩阵构成。在这种情况下，介质是