简介：软事被观察异常粘性行为经常在声学的波浪繁殖由幂定律频率依赖者变细描绘了。最近的十年在为如此的异常粘性行为，礼品，作者们经由积极部分衍生物在哪个之中建议了修改Szabo的波浪方程开发各种各样的模型上见证快成长研究。学习是使用修改Szabo的波浪方程模仿一种最近的超声的成像技术的这的目的把临床的amplitudevelocity重建称为具有典型软织物事的胸肿瘤的成像(CARI)。调查在超声的医药成像的质量上在尺寸的效果和肿瘤的位置上被做了。它从数字结果被观察沿着思考的线的健全压力，它显示察觉结果，与尺寸和肿瘤的侧面的位置显然变化，但是几乎仍然是为不同轴的位置的一样。

简介：Wavepropagationintwo-dimensionalhierarchicalhoneycombstructureswithtwoorderhierarchyisinvestigatedbyusingthesymplecticalgorithm.Byapplyingthevariationalprincipletothedualvariables,thewavepropagationproblemistransformedintoatwo-dimensionalsymplecticeigenvalueproblem.Thebandgapsandspatialfilteringphenomenaareexaminedtofindthestopbandsanddirectionalstopbands.Specialattentionisdirectedtotheeffectsoftherelativedensityandthelengthratioonthebandgapsandphaseconstantsurfaces.Thisworkprovidesnewopportunitiesfordesigninghierarchicalhoneycombstructuresinsoundinsulationapplications.

简介：Constitutiverelationsfornonlinear,isotropic,electroelasticsolidsquadraticinthefinitestraintensorandthereferentialelectricfieldarederivedfromthefullnonlinearitytheoryofelectroelasticitybytensorinvariants,whichcandescribethebehaviorofelectrostrictivematerials.Theequationsarelinearizedforsmall,dynamicfieldssuperposedonfinite,staticbiasedfields.Theselinearequationsareusedtostudyplanewavespropagatinginanelectroelasticbodyundervariousmechanicaland/orelectricbiasedfields.Itisshownthatthespeedoftheacousticwavesexhibitsastrongdependenceuponthosematerialparametersinthenonlinearconstitutiverelations.Experimentaldeterminationofthesematerialparametersusingthisdependenceisdiscussed.

简介：Thepurposeofthispaperistostudythedynamicbehaviorofsoftgroundincludingaporouslayerbyconsideringtheporositychange.Inordertotaketheporositychangeintoaccount,theconceptofthevolumefraction,whichhasbeenproposedincontinuummechanics,isintroduced.TheconstitutiveequationspresentedbyBowenareappliedtotheanalysisoftheporousmedia.AccordingtoBowen’stheory,theporosityisconsideredasavariablecalledthevolumefractionandhasitsownconsti-tutiveequation.Theconstitutiveequationofthevolumefractionhasthermoelasticequationcoefficientsandisdeterminedbythestrainsofthesolidandthefluid.Thismeansthatthecompressibilitiesofthesolidandthefluidareconsidered.Whenthespecialconditionisassumed,Bowen’stheorycancontainBiots’stheory,whichhasbeenappliedinearthquakeengineering.Thewavepropagationinthegroundincludingaporouslayer,modeledbyBowen’stheory,isstudiedandcomparedwiththatofBiot’stheory.One-di-mensionalattenuationandsurfaceamplitudearecalculated.Theeffectofthevolumefractionisdiscussedwithrespecttothecompressibilitiesofthesolidandthefluid.

简介：Themulti-parameterinversescatteringproblemofelasticwaveequationwithsinglefre-quencyisinvestigatedwithinBornapproximation.Byuseofawidebandmeasuringschemeinwhichbothtransmittersandreceiversscanoverthehalf-spacesurface,theformulaofthescatteringfieldofelasticwaveisderived.Fourtypesofmodeconversionofelasticwave(P→P,P→S,S→P,S→S)areseparatedfromthescatteringfield.Thesecomponentscontainsufficientinformationforustorecon-structtheconfigurationsofthedensityandLaméparametersofthemedium.Theinverseformulashavetheformoffilteredback-propagationasintheacousticdiffractiontomography.Computersimu-lationsarealsoobtained.

简介：Thispaperisconcernedwiththenumericaltechniquebasedonthemethodofcharacter-isticsforthree-dimensionaldynamicthermoelasticproblems.Anumericalexampleforthethree-di-mensionalstresswavepropagationinathermoelasticbarofsquarecrosssectionsubjectedtobothanimpactloadingandathermalshockispresented.

简介：Inthispaper,amathematicalmodelforLovewavepropagationinaporouselasticlayerunderarigidboundaryrestingoveraporo-elastichalf-spacehasbeendeveloped.ThestudyshowsthatsuchamediumtransmitstwotypesofLovewaves.ThefirstfrontdependsonthechangeinvolumefractionoftheporeswhereasthesecondfrontdependsuponthemodulusofrigidityoftheelasticmatrixofthemediumandisthesameastheLovewaveinanelasticlayeroveranelastichalf-space.Itisobservedthatthefirstfrontismanytimesfasterthantheshearwaveinthemediumwithvoidporesduetothechangeinthevolumefractionoftheporesandissignificant.

简介：Aboundaryelementmethodforthree-dimensionalsteadyshipwave-makingpotentialproblemsisestablishedwiththeRankinesoureefunctionasitsfundamentalsolution.Inthetreatmentofthelinearizedfreesurfacecondition,onesided.upstreamfinitedifferenceoperator(FDO)isusedtosuppresstheupstreamwaves,andtheequationofthedisturbancevelocityisestablishedsothatthefirstorderFDOcanbeusedinplaceofthesecondorderFDO.Comparedwiththemethodwiththesec-ondorderFDO,thecurrentmethodgivesbetterprecisionandstability.Numericalexamplesarepre-sentedforverification.

简介：Theinversionofstongscattererembeddedinthehalf-spaceisanimportantprobleminengi-neeringandaverydifficultnonlinearprolbeminmathematics,forwhichtheBorniterativemethodisofnoeffect.Inthispaperthemomentmethodisusedinthediscretizationprocedure.Anumericalapproachispr-esentedbyemployingtheregularizationtechniqueandDBI(distortedBorniterative)method.Thesimulationresultsshowthattheapproachpresentedisefficient.

简介：Theinteractionofanti-planeelasticSHwaveswithaperiodicarrayofinterfacecracksinamulti-layeredperiodicmediumisanalyzedinthispaper.AperfectperiodicstructurewithoutinterfacecracksisfirststudiedandthetransmissiondisplacementcoefficientisobtainedbasedonthetransfermatrixmethodinconjunctionwiththeBloch-Floquettheorem.Thisisthengeneralizedtoasingleandperiodicdistributionofcracksatthecenterinterfaceandtheresultiscomparedwiththatofperfectperiodiccaseswithoutinterfacecracks.Thedependenceofthetransmissiondisplacementcoefficientonthefrequencyoftheincidentwave,theinfluencesofmaterialcombination,crackconfigurationandincidentanglearediscussedindetail.Comparedwiththecorrespondingperfectperiodicstructurewithoutinterfacecracks,anewphenomenonisfoundintheperiodiclayeredsystemwithasingleandperiodicarrayofinterfacecracks.

简介：TheGreen’sfunctionisusedtosolvethescatteringfarfieldsolutionofSH-wavebyamov-ablerigidcylindricalinterfaceinclusioninalinearelasticbody.First,asuitableGreen’sfunctionisdevel-oped,whichisthefundamentaldisplacementsolutionofanelastichalfspacewithamovablerigidhalf-cylin-dricalinclusionimpactedbyout-of-planeharmoniclinesourceloadedatanypointofitshorizontalsurface.ByusingtheGreen’sfunction,aseriesofFredholmintegralequationsofthefirstkindwhichdeterminethescatteringfarfieldcanbesetup.Thenthepapergivestheexpressionsonthefarfieldincludingthedisplace-mentmodeofscatteringwaveandthesolutionofscatteringcross-section.Finally,someexamplesandnu-mericalresultsarediscussedtoanalyzetheinfluenceofthecombinationofdifferentmediaparametersontheansweroffarfield.

简介：ExplicitexpressionsofMori-Tanaka’stensorforatransverselyisotropicfiberreinforcedUDcompositearepresented.Closed-formformulaefortheeffectiveelasticpropertiesofthecompositeareobtained.Ina3Dsense,theresultingcompliancetensorofthecompositeissymmetric.Nevertheless,the2DcompliancetensorbasedonadeterioratedMori-Tanaka’stensorisnotsymmetric.Noristhecompliancetensordefineduponadeteriorated2DEshelby’stensor.Thein-planeeffectiveelasticpropertiesgivenbythosethreeapproachesaredifferent.AdetailedcomparisonbetweenthepredictedresultsobtainedfromthoseapproacheswithexperimentaldataavailableforanumberofUDcompositesismade.更多还原

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简介：Anin-depthanalysisofpropagationcharacteristicsofelasto-plasticcombinedstresswavesincircularthin-walledtubeshasbeenmade.Inobtainingthesimple-wavesolution,however,mostresearcheshaveignoredtheinfluenceofthecircumferentialstressrelatedtotheradialinertialeffectinthetubes.Inthispapertheincrementalelasto-plasticconstitutiverelationswhichareconvenientfordynamicnumericalanalysisareadopted,andthefinite-differencemethodisusedtostudytheevolutionandpropagationofelasto-plasticcombinedstresswavesinathin-walledtubewiththeradialinertialeffectofthetubeconsidered.Thecalculationresultsarecomparedwiththoseobtainedwhentheradialinertialeffectisnotconsidered.Thecalculationresultsshowthattheradialinertialeffectofatubehasafairlygreatinfluenceonthepropagationofelasto-plasticcombinedstresswaves.

简介：Anexplicitfull-fieldexpressionoftheGreen’sfunctionsforanisotropicpiezoeleetricbimateri-alswithaslippinginterfaceisderived.Whentheelectro-elasticsingularityreducestoapraydislocationindisplacementandelectricpotential,interactionenergy,betweenthedislocationandthebimaterialsisobtainedexplicitlywhilethegeneralizedforceonthedisloeationisgiveninarealformwhiehisalsovalidfordegener-atematerials.Theinvestigationdemonstratesthatthehoundaryconditionsatlheslippinginterfacebetweentwopiezoelectricmaterialswillexertaprominentinfluenceonthemobilityofthedislocation.

简介：Inthispaper,afiniteelementmethodisdevelopedtonumericallyevaluatetheshearcoefficientofTimoshenko'sbeamwithmultiplyconneetedcrosssection.Withfocusonanalyzingshearstressesdistributedattheneutralaxisofthebeam,animproveddefinitionoftheshearcoefficientispresented.Basedonthisdefinition,aGalerkin-typefiniteelementformulationisproposedtoanalyzetheshearstressesandsheardeflections.Numericalsolutionsoftheexamplesforsometypicalcross-sectionsarecomparedwiththetheoreticalresults.TheshearcoefficientoftowersectionsoftheTsingMaBridgeiscalculatedbyuseoftheproposedapproach,sothatthefiniteelementmodelingofthebridgecanbedevelopedwiththeaccuratevaluesofthesectionalproperties.

简介：ShouwenYu,emeritusProfessorofAppliedMechanicsatTsinghuaUniversity,wasbornonMay4,1939inXianyouCounty,FujianProvinceofChina.From1955to1958,hestudiedasanundergraduate