简介:在这份报纸,为multiferroic的三维的有限元素的明确的表达合成为它的短暂分析被开发并且实现进商业软件ABAQUS。首先,一个特殊三维的八节点的稳固的元素被设计处理用橡皮做的合成的multiferroic,压电,并且piezomagnetic材料。第二,为这个最新发达的元素的一个自定义子程序被实现进ABAQUS。最后,双性人分层的multiferroic的短暂回答合成被使用直接时间集成方法计算。二个典型磁性的潜在的信号,高斯和Ricker脉搏,被用于与刺激的各种各样的时间持续时间合成。短暂反应能被输入实质地影响的导致的电场表演发信号,它能为最强壮的电的输出被调节。
简介:我们调查在压电的分层的结构的起始的应力的效果装载了与的经分解粘滞爱的散、稀释的特征上的液体飘动,它包含薄压电的层完美地结合了到无界的有弹性的底层。在压电的层的起始的应力的效果并且粘滞爱波浪的阶段速度上的液体的系数被分析。数字结果被介绍并且讨论。分析方法和结果能为化学药品和biosensing液体传感器的设计是有用的。
简介:Inthisstudy,avariationalapproachtothesettlementanalysisofanaxiallyloadedpierem-beddedinamulti-layeredsoilprofileispresented.Inthismethod,thesoilprofileandtheembeddedpieraredividedintoanumberofsub-layersaccordingtotheactualnumberofsoillayersobservedinthefield.ThedisplacementshapefunctionofeachsoillayerisgivenasaproductofanexponentialequationalongthepierdepthandtheBessel’ssolutionintheradialdirection.Thedisplacementrelationshipamongthelayerscanbederivedthroughthetransformationmatrices.Oneofthemajorfeaturesofthismethodisthatthetotalnumberofpierelementsisthesameasthatofsoilsub-layers.Allthefieldcompontents,suchasthedisplacement,stress,andstraininthesoil,canbecalculatedbyclosed-formsolutionsexceptthattheonlyunknownvari-ableisthevalueβwhichcanbedeterminedbyiterationtechniques.Comparisonsweremadewiththeresultsoffiniteelementanalysisandthefieldobservationinpile-loadedtests.
简介:Theinteractionofanti-planeelasticSHwaveswithaperiodicarrayofinterfacecracksinamulti-layeredperiodicmediumisanalyzedinthispaper.AperfectperiodicstructurewithoutinterfacecracksisfirststudiedandthetransmissiondisplacementcoefficientisobtainedbasedonthetransfermatrixmethodinconjunctionwiththeBloch-Floquettheorem.Thisisthengeneralizedtoasingleandperiodicdistributionofcracksatthecenterinterfaceandtheresultiscomparedwiththatofperfectperiodiccaseswithoutinterfacecracks.Thedependenceofthetransmissiondisplacementcoefficientonthefrequencyoftheincidentwave,theinfluencesofmaterialcombination,crackconfigurationandincidentanglearediscussedindetail.Comparedwiththecorrespondingperfectperiodicstructurewithoutinterfacecracks,anewphenomenonisfoundintheperiodiclayeredsystemwithasingleandperiodicarrayofinterfacecracks.
简介:Phononicmaterialswithspecificband-gapcharacteristicsatdesiredfrequencyrangesareingreatdemandforvibrationandnoiseisolation,elasticwavefilters,andacousticdevices.Theattenuationcoefficientcurvedepictsboththefrequencyrangeofbandgapandtheattenuationofelasticwave,wherethefrequencyrangescorrespondingtothenone-zeroattenuationcoefficientsarebandgaps.Therefore,theband-gapcharacteristicscanbeachievedthroughmaximizingtheattenuationcoefficientatthecorrespondingfrequencyorwithinthecorrespondingfrequencyrange.Becausetheattenuationcoefficientcurveisnotsmoothinthefrequencydomain,thegradient-basedoptimizationmethodscannotbedirectlyusedinthedesignoptimizationofphononicband-gapmaterialstoachievethemaximumattenuationwithinthedesiredfrequencyrange.Toovercomethisdifficulty,theobjectiveofmaximizingtheattenuationcoefficientistransformedintomaximizingitsCosine,andinthisway,theobjectivefunctionissmoothedandbecomesdifferentiable.Basedonthisobjectivefunction,anovelgradient-basedoptimizationapproachisproposedtoopenthebandgapataprescribedfrequencyrangeandtofurthermaximizetheattenuationefficiencyoftheelasticwaveataspecificfrequencyorwithinaprescribedfrequencyrange.Numericalresultsdemonstratetheeffectivenessoftheproposedgradient-basedoptimizationmethodforenhancingthewaveattenuationproperties.
简介:Amethodisdevelopedforcyclicelastoplasticanalysisacrossmicro/meso/macroscaleswhichiseffectiveforthequantitativetransitionofphysicalvariablesandforevaluatingthesizeeffectsofmicrostruc-tures.Byusingtheimprovedself-consistentsehemeproposedbyFanandcarryingoutadelicatemesoscop-icanalysisbasedonashear-lagmodel,thesizeeffectsincludingthethicknessofhardandsoftlayersrelativetotheinclusiondimensionareobtainedontheoverallelastoplasticresponsesofmaterialsupto50cycles.Thedominantcharacteristicsoftheanalysisrarethatthecharacteristicdimensionsofamicrostructuresuchasthethicknessofthelayersandtheinclusiondimensioncanbeexplicitlyincorporatedintotheformulation.Resultsofnumericalanalysisusingonly4plasticconstantsshowthatthethickerthelayerrelativetothein-clusionsize,thesofterthematerialinproducingmoreplasticstrainvaluesforagivenappliedstressampli-tude.Thisisinagreementwiththewell-knownexperimentalrulethattheyieldstrengthoflayeredstructuresisinverselyproportionultothesquarerootofthespacingbetweenlayers.Itisfoundthatratchetingdependsverymuchonthesizeofthelayered-structureandthatthethinnertherelativethicknessofthelayerthelesstheratchetiugdisplacement.Thisfindingmaybeusedtoexplainwhyphenomenologicalmodelsonratchetingarenotquitesuccessfulsofar,indicatingthesignificanceofaerossscaleanalysisinunderstandingissueswhichhaveexistedforalongtime.
简介:Ameshlessradialbasisfunction(RBF)collocationmethodbasedontheEringennonlocalelasticitytheoryisdevelopedtocalculatethebandstructuresofternaryandquaternarynanoscalemulti-layeredphononiccrystals(PNCs)withfunctionallygraded(FG)interlayers.Detailedcalculationsareperformedforanti-planetransversewavespropagatinginsuchPNCs.TheinfluencesofFGandhomogeneousinterlayers,componentnumber,nonlocalinterfaceimperfectionsandnanoscalesizeoncut-offfrequencyandbandstructuresareinvestigatedindetail.Numericalresultsshowthatthesefactorshavesignificanteffectsonbandstructuresatthemacroscopicandmicroscopicscales.