简介：Thispaperpresentsanewboundaryintegralequatiònfortwo-dimensionalelasticitywiththestresscomponentσijtitjasoneoftheboundaryvalues,wheretiisthedirectioncosineofthetangentontheboundary.ThisformofBEMhasanadvantageinthatthestresscomponentσijtitjontheboundarycanbecalculateddirectlyfromthenumericalsolution.Thepresentformulationforplaneproblemsusestwokernels,theoneislogarithmicallysingularandtheotheris1/rsingular.Theeffectivenessoftheapproachisalsodiscussedthroughtestexamples.

简介：ThispaperprovidesasolutionforthedegeneratescaleforN-gonconfigurationinantiplaneelasticityusingtheconformalmappingfunction,andthelowerandupperboundsforthedegeneratescaleforN=3,4,5,6,7,8,10,20,30,40,50,100,150and200,areevaluated.

简介：Formulationintermsofhypersingularintegralequationsfortheinteractionbetweenstraightandcurvedcracksinplaneelasticityisobtainedusingthecomplexvariablefunctionsmethod.Thecurvedlengthcoordinatemethodandasuitablenumericalschemeareusedtosolvesuchintegralsnumericallyfortheunknownfunction,whicharelaterusedtofindthestressintensityfactor,SIF.

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

简介：Basedontheexperimentalresultsofsuper-elasticNiTialloy,athree-dimensionalsuper-elasticconstitutivemodelincludingbothofstress-inducedmartensitetransformationandplasticityisconstructedinaframeworkofgeneralinelasticity.Intheproposedmodel,transformationhardening,reversetransformationofstress-inducedmartensite,elasticmismatchbetweentheausteniteandmartensitephases,andtemperature-dependenceoftransformationstressandelasticmodulusofeachphaseareconsidered.Theplasticyieldingofmartensiteoccurredunderhighstressisaddressedbyabilinearisotropichardeningrule.Drucker-Prager-typedtransformationsurfacesareemployedtodescribetheasymmetricbehaviorofNiTialloyintensionandcompression.Thepredictioncapabilityoftheproposedmodelisverifiedbycomparingthesimulatedresultswiththecorrespondentexperimentalones.BasedonbackwardEuler'sintegration,anewexpressionofconsistenttangentmodulusisderived.TheproposedmodelisthenimplementedintoafiniteelementpackageABAQUSbyuser-subroutineUMAT.Finally,thevalidityofsuchimplementationwasverifiedbysomenumericalsamples.

简介：Vibrationcharacteristicsoffluid-filledmulti-walledcarbonnanotubesarestudiedbyusingnonlocalelasticFlu¨ggeshellmodel.VibrationgoverningequationsofanN-layercarbonnanotubeareformulatedbyconsideringthescaleeffect.Inthenumericalsimulations,theeffectsofdifferenttheories,small-scale,variationofwavenumber,theinnermostradiusandlengthofdoublewalledandtriple-walledcarbonnanotubesareconsidered.Vibrationalfrequenciesdecreasewithanincreaseofscalecoefficient,theinnermostradius,lengthofnanotubeandeffectsofwallnumberarenegligible.Theresultsshowthatthecut-offfrequenciescanbeinfluencedbythewallnumberofnanotubes.

简介：Inthispaper,ageneralsolutionforthree-dimensionalstaticpiezothermoelasticprob-lemsofcrystalclass6mmsolidsispresented.Tnegeneralsolutioninvolvesfourpiezoelasticpotentialfunctionsandapiezothermoelasticpotentialfunction,ofwhichfourpiezoelasticpotentialfunctionsaregovernedbyweightedharmonicdifferentia[equations.ComparedwiththegeneralsolutiongivenbyAshidaetal.,inwhichsevenpotentialfunctionsareintroduced,thegeneralsolutionproposedinthepresentpaperismorerigorouslyderived.Moreover,ithasasimpleformandisconvenientforappli-cation.Asanillustrativeexample,theproblemofapyroelectrichalf-spacesubjectedtoaxisymmetricheatingisstudied.Numericalresultsofdisplacements,stresses,electricpotentialandelectricdisplace-mentsareobtainedforacadmiumselenidehalf-space.Thermallyinduceddisplacementsandstressdis-tributionarecomparedwiththoseobtainedforthesamematerialwithoutpiezoelectricandpyroelectriceffects.

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简介：Westudyelectromechanicalfieldsintheanti-planedeformationofaninfinitemediumofpiezoelectricmaterialsof6mmsymmetrywithacircularcylindricalhole.Thetheoryofelectroelasticdielectricswithelectricfieldgradientintheconstitutiverelationsisused.Specialattentionispaidtothefieldsnearthesurfaceofthehole.

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