简介：BaseduponStrohformalismwederiveanovelandconvenientschemefordeterminingtheelasticfieldsofatwo-dimensionalanisotropicbodywithaparabolicboundarysubjecttotwokindsofboundaryconditions,whicharefreesurfaceandrigidsurface,respectively.ThecorrespondingGreen’sfunctionsarefoundbyusingtheconformalmappingmethod.Whentheparaboliccurvede-generatesintoahalf-infinitecrackorrigidinclusion,thesingularstressfieldsnearthetipofdefectsareobtained.Inparticular,thoseGreen’sfunctionsforaconcentratedmomentM0appliedatapointontheparaboliccurvearealsostudied.Itiseasilyfoundthatarbitraryparabolicboundaryvalueprob-lemscanbesolvedbyusingtheseGreen’sfunctionsandassociateintegrals.

简介：Theboundaryintegralequation(BIE)ofdisplacementderivativesisputatadisadvantageforthedifficultyinvolvedintheevaluationofthehypersingularintegrals.Inthispaper,theoperatorsδijandεijareusedtoactonthederivativeBIE.Theboundarydisplacements,tractionsanddisplacementderivativesaretransformedintoasetofnewboundarytensorsasboundaryvariables.AnewBIEformulationtermednaturalboundaryintegralequation(NBIE)isobtained.TheNBIEisappliedtosolvingtwo-dimensionalelasticityproblems.IntheNBIEonlythestronglysingularintegralsarecontained.TheCauchyprincipalvalueintegralsoccurringintheNBIEareevaluated.AcombinationoftheNBIEanddisplacementBIEcanbeusedtodirectlycalculatetheboundarystresses.ThenumericalresultsofseveralexamplesdemonstratetheaccuracyoftheNBIE.

简介：尽管边界排水量和拖拉是处于在一个非退化的边界点的一个弹性问题的边界条件的独立的地变量，在那里存在在在一条单个边界的边界排水量衍生物和拖拉之间的奇特紧张的明确的关系指。在为2D的一个单个光滑的点的关系的分析表格各向同性的有弹性的问题在这个工作被建立了。由使用关系，单个边界点的位置和未知边界的相应奇特紧张回答变量能被决定priori。因此，未知边界的更适当的形状函数在单个元素回答变量能被构造。一个数字例子证明用发达理论的BEM分析的精确性极大地被增加。

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

简介：Accordingtotheclassicalelastictheory,thereisalwaysadiscontinuityofrotationangleontheinterfacebetweendifferentmaterials.Thisillogicresultcanbeovercomebythestraingradientplasticitytheory.Inthelightofthistheory,thereisagroupofboundarylayersolutionsnearthein-terface,whichhavemadeimportantadjustmentoftheclassicalresults.

简介：Amathematicalprogramisproposedforthehighlynonlinearprobleminvolvingfrictionalcontact.Aprogram-patternusingthefastmultipoleboundaryelementmethod(FMBEM)isgivenfor3-DelasticcontactwithfrictiontoreplacetheMonteCarlomethod.Anewoptimizedgeneralizedminimalresidual(GMRES)algorithmispresented.Numericalexamplesdemonstratethevalidityoftheprogram-patternoptimizationmodelfornode-to-surfacecontactwithfriction.TheGMRESalgorithmgreatlyimprovesthecomputationalefficiency.

简介：AnumericalanalysiswascarriedouttostudythemovingboundaryprobleminthephysicalprocessofpulsedNd-YAGlasersurfacemeltingpriortovaporization.Theenthalpymethodwasappliedtosolvethistwo-phaseaxisymmetricalmehingproblem.Computationalresultsoftemperaturefieldswereobtained,whichprovideusefulinformationtopracticallairtreatmentprocessing.Thevalidityofenthalpymethodinsolvingsuchproblemsispresented.

简介：ThisinvestigationpresentstheGreenfunctionsforadecagonalquasicrystallinematerialwithaparabolicboundarysubjecttoalineforceandalinedislocationbymeansofthecomplexvariablemethod.ThesurfaceGreenfunctionsaretreatedasaspecialcase,andtheexplicitexpressionsofdisplacementsandhoopstressattheparabolicboundaryarealsogiven.Finally,thestressesanddisplacementsinducedbyaphononlineforceactingattheoriginofthelowerhalf-spacearepresented.

简介：Theboundaryelementmethodisusedforthemodalanalysisoffreevibrationof2-Dcompositestructuresinthispaper.Sincetheparticularsolutionmethodisusedtotreatthetermsofbodyforces(inertialforces)intheequationofmotion,onlystaticfundamentalsolutionsareneededinsolvingtheproblem.Foranisotropiccantileverbeam,thenumericalresultsobtainedbyusingtheBEMpresentedinthispaperareingoodagreement,withthoseofusingFEMorotherBEM,butthisBEMcanalsobeusedtoanalyzeproblemsforanisotropicmaterials.Forsimplysupportedcompositelaminatedbeams,thecomparisonsofthenumericalresultsobtainedbythismethodwiththeanalyticalresultsobtainedby1-Dlaminatedbeamtheoryindicatethatiftheratiooflength/thicknessisgreaterthan20,theresultsofthetwomethodsareingoodagreement,butiftheratiooflength/thicknessislessthan20,bigerrorswilloccurfor1-Dlaminatedbeamtheory.

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

简介：Inthispaperthedualreciprocityboundaryelementmethodisemployedtosolvenonlineardifferentialequation~2u+u+εu~3=b.ResultsobtainedinanexamplehaveagoodagreementwiththosebyFEMandshowtheapplicabilityandsimplicityofdualreciprocitymethod(DRM)insolvingnonlineardif-ferentialequations.

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

简介：Freevibrationproblemsoflatticesandwichbeamsunderseveraltypicalboundaryconditionsareinvestigatedinthepresentpaper.Thelatticesandwichbeamistransformedtoanequivalenthomogeneousthree-layeredsandwichbeam.Unlikethetraditionalanalyticalmodelinwhichtherotationanglesofthefacesheetsandthecoreareassumedthesame,diferentrotationanglesareconsideredinthispapertocharacterizetherealresponseofsandwichbeams.Theanalyticalsolutionsofthenaturalfrequenciesforseveraltypicalboundaryconditionsareobtained.Theefectsofmaterialpropertiesandgeometricparametersonthenaturalfrequenciesarealsoinvestigated.

简介：Basedonlinearized2-DNavier-Stokesequation,aLaplacetransform-boundaryelementcouplingmethodforviscousfluid-structureimpactanalysisisproposed.Underassumptionofincompressibilityforthefluid,thecorrespondingequivalentboundaryintegralequationintermsofthepotentialfunctionandstreamfunctionisfirstestablishedbyLamb’stransformintheLaplacetransformdomain.Itenablesustosolveim-pactwaterproblemsinfrequencydomainbytheboundaryelementmethod,inwhichtheeffectofviscousflowonthedynamicresponsecanbetakenintoaccount.Thenacompletesolutionoftheproblemunderconsider-ationintimedomainisobtainedbymeansofDurbin’sformulasforthenumericalinversionoftheLaplacetransform.Finally,apracticalexampleisgiventoconfirmthevalidityofthepresentmethod.

简介：Themillrollerbeatingismadeupofaninternalring,middlerollsandanexternalring,theanalysisofwhiehisamulti-bodiescontactproblem.Inthispaper,basedonthethree-dimensionalelasticcontactBEMwithoutfriction,andusingthestructuralcharacteristicsofrollerbearings,middlerollsarede-scribedbyelasticplateunitsofdifferentshapes,whichisplacedontheinternalring.Thediscontinuoustractionproblemofthecontactelementcanbedealtwithbythetractionsub-elementmethod.Thereforethecontactproblemcanbechangedfroinoneofmulti-bodiestooneoftwo-bodies.Asanelasticdeformationoftheplateelement,itcanbecalculatedbyanelasticcontactformulaandisregardedananequivalentgaptobeputintothetotalmatrixequality.Theface-to-facecontactconditionofdisplacementandtractionontheelementwillnerveastheconvergencejudgingcondition.Soconvergencesolutioncanbeobtainedbeforeanygeometryinconsistentonthecontactelementmaytakeplace.Therefore,thethree-dimensionaldistributionofloadofthemillrollerbearingcanbeachieved,Ithasbeenprovedthatthecalculatingmodelofthismethodisvisualizedandsimple,haslastconvergencesolutionandhigheraccuracy,makingitaneffectivenumericalmethodofdesigningandanalyzingloadcharacteristicsofthemillrollerbearing.

简介：Thesingularboundarymethod(SBM)isarecentmeshlessboundarycollocationmethodthatremediestheperplexingdrawbackoffictitiousboundaryinthemethodoffundamentalsolutions(MFS).Thebasicideaistousetheoriginintensityfactortoeliminatesingularityofthefundamentalsolutionatsource.Themethodhassofarbeenappliedsuccessfullytothepotentialandelasticityproblems.However,theSBMsolutionforlarge-scaleproblemshasbeenhinderedbytheoperationcountofO(N~3)withdirectsolversorO(N~2)withiterativesolvers,aswellasthememoryrequirementofO(N~2).Inthisstudy,thefirstattemptwasmadetocombinethefastmultipolemethod(FMM)andtheSBMtosignificantlyreduceCPUtimeandmemoryrequirementbyonedegreeofmagnitude,namely,O(N).Basedonthecomplexvariablerepresentationoffundamentalsolutions,theFMM-SBMformulationsforbothdisplacementandtractionwerepresented.Numericalexampleswithuptohundredsofthousandsofunknownshavesuccessfullybeentestedonadesktopcomputer.TheseresultsclearlyillustratedthattheproposedFMM-SBMwasveryefficientandpromisinginsolvinglarge-scaleplaneelasticityproblems.

简介：Thispaperinvestigatestheequivalentmodelforthefrictionboundaryconditionbetweenblankandholderduringsheetmetalformingsimulation,andproposesanequivalentalgorithm,thethicknessthresholdvaluealgorithm,forthefirsttimebasedonthicknessweighting.Thisalgorithmassumesthattheholderclearanceisuniformduringsheetmetalforming;andthemainreasonfortheunevennessoffrictionforcedistributionundertheholderisthattheunevendeformationoftheblankleadstoitsuneventhicknessdistribution,whichmakesthelocalpressureontheblankdistributedunevenly.Thealgorithmproposedinthispapercaneffectivelysimulatetheinfluenceoftheunevennessontheformingprocess.Validityofthisalgorithmisverifiedbyacomparisonbetweenthesimulationresultsandtheexperimentalonesforthedrawingprocessofacarspringbase.

简介：有混合边界节点方法(HBNM)的联合双交换方法(DRM)，双交换混合边界节点方法(DRHBNM)与身体力量为三维的线性弹性问题被开发。没有领域积分，这个方法能被用来与身体力量解决弹性问题，它由HBNM是不可避免的。表明通用性和这个方法的快集中，有身体力量的3-D弹性问题的一些数字例子被检验。计算结果证明现在的方法是有效的并且能广泛地在解决实际工程问题被使用。

简介：Aboundaryelementmethodispresentedforthecoupledmotionanalysisofstructuralvibrationwithsmall-amplitudefluidsloshingintwo-dimensionalspace.ThelinearizedNavier-Stokesequationsareconsideredinfrequencydomainandtransformedintoboundaryintegralequations.AnappropriatefundamentalsolutionfortheHelmholtzequationwithpureimaginaryconstantisfound.Theconditionofzero-stressisimposedonthefreesurface,andnon-slipconditionoffluidparticlesisimposedonthewallsofthecontainer.Forrigidmotionmodels,theexpressionsforaddedmassandaddeddampingtothestructuralmotionequationsareobtained.Sometypicalnumericalexamplesarepresented.

简介：Aschemeisdevelopedforanalysingtheinteractionbetweenafoundationandanonlin-earrockandsoilmedium,inwhichthefoundationisconsideredasalinearelasticbodyandatypicalboundaryintegralequationmethod(BIEM)isemployed.(hathebasisoftakingthenonlinearproper-tiesofthemediumintoaccount,aperturbationBIEMisdeveloped.Thefundamentalequationsforthenonlinearcouplinganalysisareformulated,andtypicalproblemsaresolvedanddiscussedbythepre-sentmethod.