简介：Asolutionispresentedforaclassoftwo-dimensionalelectroelasticbranchedcrackproblems.ExplicitGreen’sfunctionforaninterfacecracksubjecttoanedgedislocationisdevelopedusingtheextendedStrohformulationallowingthebranchedcrackproblemtobeexpressedintermsofcoupledsingularintegralequations.Theintegralequationsareobtainedbythemethodthatmodelsakinkasacontinuousdistributionofedgedislocations,andthedislocationdensityfunctionisdefinedonthelineofthebranchcrackonly.Competitionbetweencrackextensionalongtheinterfaceandkinkingintothesubstrateisinvestigatedusingtheintegralequationsandthemaximumenergyreleaseratecriterion.Numericalresultsarepresentedtoshowtheeffectofelectricfieldonthepathofcrackextension.

简介：Thispaperdealswiththeelectro-elasticcouplinginteractionbetweenapiezoelectricscrewdislocationwhichislocatedinsidetheellipticalinhomogeneityandanelectricallyconductiveconfocalrigidlineunderremoteanti-planeshearstressesandin-planeelectricalloadsinpiezoelectriccompositematerial.Theanalytical-functionsofthecomplexpotentials,stressfieldsandtheimageforceactingonthepiezoelectricscrewdislocationareobtainedbasedontheprincipleofconformalmapping,themet...

简介：基于颤动的精力harvester是实质上在一个有限频率范围工作的一个共鸣器。增加工作频率范围是一个挑战性的问题。这份报纸为提高经由内部回声收获的精力揭示新奇可能性。内部回声精力harvester被建议。刺激连续地作为Gaussian白噪音，一个秒顺序过滤器定义的有颜色的噪音，狭窄乐队的噪音，和指数地相关的噪音被假定。相应平均root-mean-square产量电压被计算。数字结果证明内部回声增加操作带宽和产量电压。

简介：Mechanicalandelectricaldamagesareintroducedtostudythefracturemechanicsofpiezoelectricceramicsinthispaper.Twokindsofpiezoelectricfracturecriteriaareestablishedusingthemethodofleastsquarescombinedwithadamageanalysisofthewell-knownpiezoelectricfractureexperimentsofParkandSun's.Oneisbasedonalinearcombinationofthemechanicalandelectricaldamagesandtheotherontheirnonlinearcombination.WhenthecombineddamageDisuptoitscriticalvalueDc,piezoelectricfractureoccurs.Itisfoundfromthequalitativecomparisonofthenumericalresultswiththeexperimentaldatathatthenonlinearlycombineddamagefracturecriterioncangiveabetterpredictionofpiezoelectricfracture.Anditisconcludedfromthenonlinearlycombineddamagefracturecriterionthatanegativeelectricfieldimpedesfracturewhereastheeffectofapositiveelectricfieldonfracturedependsonitsmagnitude.

简介：Wereportthefabricationprocessofpiezoelectriccellulosepaperandtheenhancementmethodofitspiezoelectricproperty.Stretchingmethodwithdifferentwet-drawingratioswasintroducedtoincreasethepiezoelectricpropertyofcellulosepaperduringregenerationprocess.ItisobservedthattheYoung’smodulusandthepiezoelectricchargeconstantsareverydependentonthedrawingratioandthedirectionofnanofibrilsofpiezoelectricpaper.Usingtheenhancedpiezoelectricproperty,weprovethattheflexibleregeneratedpiezoelectriccellulosecanbeappliedtothepotentialacousticapplicationssuchasthinpiezoelectricpaperspeaker.

简介：Thecoupledelasticandelectricfieldsforanisotropicpiezoelectricmaterialswithelectri-callypermeablecracksareanalyzedbyusingStrohformulainanisotropicelasticity.ItisshownfromthesolutionthatthetangentcomponentoftheelectricfieldstrengthandthenormalcomponentoftheelectricdisplacementalongthefacesofcracksareaUconstants,andtheelectricfieldintensityandelec-tricdisplacementhavethesingularityoftype(1/2)atthecracktip.Theenergyreleaserateforcrackpropagationdependsonboththestressintensityfactorandmaterialconstants.Theelectricfieldinten-sityandelectricdisplacementinsideelectricallypermeablecracksareallconstants.

简介：在同类的压电的脱衣的平行裂缝的一个周期的数组的问题结合了到机能上地分级的压电的材料为不同类的连续统被调查。材料不同类沿着裂缝的方向作为在指数的功能形式的shear模量的空间变化被代表，这被假定。混合边界价值问题被使用Fourier变换归结为一个单个不可分的方程，并且单个不可分的方程被使用Gauss-Chebyshev集成技术数字地解决。数字结果被获得为材料不同类的不同的值作为裂缝频率的一个函数说明压力紧张因素的变化。

简介：

简介：为压电的陶器的排放变换器匹配的Butterworth上的一条定理被介绍并且证明。宽带匹配的复杂问题由于定理的明确的公式被改变到简单的算术的。当力量获得接近1时，它在一个例子被显示出在匹配以后，变换器的带宽显著地增加。

简介：Thispapergivesanexactanalysisofarotatingpiezoelectricsphericalshellwitharbitrarythickness.Atfirst,threedisplacementfunctionsareintroducedtosimplifythebasicequationsofasphericallyisotropic,piezoelectricmedium.Byexpandingthedisplacementfunctionsaswellastheelectricpotentialintermsofsphericalharmonics,thebasicequationsofequilibriumareconvertedtoanuncoupledEulertype,secondorderordinarydifferentialequationandacoupledsystemofthreesecondorderordinarydifferentialequations.Ageneralsolutiontothehomogeneousequationsofequilibriumisthenderived.Thestaticanalysisofarotatingsphericalshellisthenperformedandnumericalexampleispresented.

简介：Thispaperpresentsthevibrationssuppressionofathermoelasticbeamsubjecttosuddenheatinputbyasinglepiezoelectricactuator.Anoptimizationproblemisformulatedastheminimizationofaquadraticfunctionalintermsofdisplacementandvelocityatagiventimeandwiththeleastcontroleffort.Thesolutionmethodisbasedonacombinationofmodalexpansionandvariationalapproaches.Themodalexpansionapproachisusedtoconverttheoptimalcontrolofdistributedparametersystemintotheoptimalcontroloflumpedparametersystem.Byutilizingthevariationalapproach,anexplicitoptimalcontrollawisderivedandthedeterminationofthecorrespondingdisplacementandvelocityisreducedtosolvingasetofordinarydifferentialequations.Numericalresultsarepresentedtodemonstratetheeffectivenessandtheapplicabilityoftheproposedmethod.

简介：Anoptimizedtransducerprototypewithasandwichstructurevibratedlongitudinallyisproposedforatransmitterinacousticlogging,especiallyinacousticloggingwhiledrilling,bytakingaccountofdrillingenvironmentswithhightemperatureandpressure,aswellasstrongcollardrillingvibrationduringthedrillingprocess.Aimedtoimprovethetransmittingperformance,numericalandexperimentalstudiesforthetransduceroptimizationareconducted.Theimpactoflocationandlengthofthepiezoelectricstackonresonancecharacteristicsandeffectiveelectromechanicalcouplingcoefficientiscalculatedandanalyzed.Admittanceandtransmittingperformanceoftheproposedtransduceraremeasuredinlaboratoryexperiments,andtheresultsarecomparedwithsimulatedones.Itisshownthatthenewlyproposedtransducerhashighertransmittingperformancewithlowerresonancefrequencies.Thisworkprovidestheoreticalandexperimentalbasesfortransducerdesigningandacousticwavemeasurementsinacousticlogging,especiallyinacousticloggingwhiledrilling.

简介：Thispaperisconcernedwiththeoptimumdesignandsensitivityanalysismethodsofpiezo-electricintelligenttrussesonthestructuralstiffnessandfree-vibrationfrequency.Onthebasisofthefiniteel-ementmethodandtakingintoaccountthemechanical-electriccouplingeffectunderelectricloadandme-chanicalload,thecomputationalformulaofsensitivitiesofstructuraldisplacementandfree-vibrationfrequen-cywithrespecttothesizeandshapedesignvariablesareproposed.Anewkindofdesignvariableoftheelectricvoltageandthecalculatingmethodofdisplacementsensitivitywithrespecttotheelectricvoltagevari-ableispresented.Thenewmethodforstructuraldeformationcontrolbyoptimizingthevoltagesofpiezoelec-tricactivebarsisgiven.ThenumericalmethodsofoptimumdesignandsensitivityanalysisforpiezoelectrictrussstructuresareimplementedinJIFEXsoftware.Numericalexamplesdemonstratetheeffectivenessofthemethodsandtheprogram.

简介：Afinitedifference/boundaryintegralproceduretodeterminetheacousticreflectedpressurefromafluid-loadedbi-laminatedplateisdescribed.Thebi-laminateiscomposedofapiezoelectriclayerandanelasticlayerincontactwiththefluid,andisheldbyanacousticallyhardbaffle.Inthenumericalmodel,thefluidpressureatfluid/solidinterfaceisreplacedbyacontinuumofpointsourcesweightedbythenormalaccelerationoftheelasticplate,andthegoverningequationsystemissolvedinthesoliddomain.Withthenormalaccelerationfound,thereflectedpressureinthefluidisdeterminedbyanintegralexpressioninvolv-ingtheGreen’sfunction.Itisdemonstratedthatanappropriateappliedvoltagepotentialacrossthepiezoelec-triclayerhastheeffectofcancellingeitherthereflectedorscatteredpressureoftheplateatanychosenfieldpointsinthefluid.

简介：这份报纸论述方法由压电的生成器从沥青人行道收获机械精力。结果证明在沥青人行道的势能能每公里每小巷直到150kW/h。机械精力的部分能被压电的变换器收获。七个典型变换器的表演通过有限元素分析被检验。PZT堆的结果表演并且多层，在沥青人行道环境的钗钹和桥罐头工作。PZT堆积并且多层更高让精力变换评价。然而，如果这些变换器在人行道直接被嵌入，全部的收获精力是小的。一个原型人行道发电机用PZT堆积被开发增加收获精力。发电机能在交通拥挤下面从人行道收获超过50kW/h精力。816PZT堆积为一个发电机被推荐。圆形状被建议让PZT堆积减少应力的集中。并且多层的结构被推荐因为PZT堆发电机的电的潜力到减少。生成器能在沥青人行道作为传感器被扩大，它能被用来监视交通，人行道压力和温度。

简介：Thepotentialforharvestingenergyfromaflexibledeltawingusingapiezoelectricbimorphisexperimentallyinvestigated.Differentconfigurationsoftheproposedharvestingsystemweretestedinawindtunneloverabroadrangeofairspeeds.Inadditiontoevaluatingthelevelofharvestedpower,ananalysisisperformedtoextractcriticalaspectsfortherelationbetweenspeed,flexibility,geometryandthepotentialpowerthatcanbeharvestedfromaclamped,cantileveredflexibledeltawingatlowanglesofattackandlowspeeds.Thisanalysisprovidesaninsightintoparametersthatimpactenergyharvestingfromflexiblemembranesorelements.

简介：Thepressurereflectedfromabi-laminatedpiezoelectricplatehasbeendeterminedusingtheThomson-Haskellmatrixmethod.Theplateiscomposedofapiezoelectriclayerwithgroundedvacuumandanelasticlayerincontactwiththefluid.Anincidentplanewaveinthefluidmediumstrikestheplateatdif-ferentangles.Therequiredelectricpotentialacrossthepiezoelectriclayertocancelthereflectionfromthefluid/elasticboundaryhasbeendeterminedforthepiezoelectricmaterialPZT-5atvariousthicknessparame-lersandincidentfrequencies.

简介：Thefiniteelementformulationforanalyzingstaticdamagenearaconductingcrackinathinpiezoelectricplateisestablishedfromthevirtualworkprincipleofpiezoelectricity.Thedamagefieldsundervariousmechanicalandelectricalloadsarecalculatedcarefullybyusinganeffectiveiterativeprocedure.Thenumericalresultsshowthatallthedamagefieldsaroundacracktiparefan-shapedandtheelectricfieldappliedhasgreatinfluenceonthemechanicaldamage,whichisrelatedtothepiezoelectricproperties.

简介：Basedonthegeneralsolutionofthree-dimensionalproblemsinpiezoelectricmedium,withthemethodofGreen’sfunctins,axisymmetricboundary-valueproblemsarediscussed.Thepurposeofthisresearchisforanalyzingtheeffectiveonmechanicsandelectricityofthepiezoelectricceramicscausedbyvoidsandinclusions.Thedisplacement,tractionandelectricGreen’sfunctionscorrespondingtocircularringloadsactingintheinteriorofapiezoelectricceramicareobtained.AcylindricalcoordinatesystemisemployedandHankeltransformareappliedwithrespecttoradialcoor-dinates.ExplicitsolutionsforGreen’sfunctionsarepresentedintermsofinfiniteintegralsofLipshitz-Hankeltype.Bysolvingatractionboundary-valueproblem,thesolutionschemeisillustrated.

简介：Anewpiezoelectricpumpcanpumpliquideitherforwardorbackwardandadjusttheflowrate.Thusanobjectcanbedrivenforwardorbackwardatdifferentspeeds.Thedriverofthepump,acircularpiezoelectricplate,ismodelledbyFiniteElementMethod(FEM)inANSYSanditsperformanceissimulatedandanalyzed.Thepumpgivesthebestperformancewhenthedrivingsignalsoftheinletandoutletvalveshaveabiggerdutycycleandtheplatehasahighervoltageapplied.