简介：用机能上地分级的材料(FGM)做的圆柱的壳的热弄弯行为被学习。材料成分由组成陶器并且金属。越过壳厚度的材料性质被假定以混合物的体积部分规则根据简单幂定律分布被分级。基于Donnell壳理论，以排水量部件弄弯的无尺寸的部分微分方程的一个系统被导出。变量的分离的方法被用来转变管理方程到平常的微分方程(颂诗)。一个射击方法被用来在边界条件的二种类型下面寻找微分方程的数字答案。幂定律索引，无尺寸的几何参数，和批评弄弯温度上的温度比率的效果详细被讨论。

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简介：Basedonthefundamentaldynamicequationsoffunctionallygradedmaterial(FGM)cylindricalshell,thispaperinvestigatesthesoundradiationofvibrationalFGMshellinwaterbymobilitymethod.ThismodeltakesintoaccounttheexteriorfluidloadingduetothesoundpressradiatedbytheFGMshell.TheFGMcylindricalshellwasexcitedbyaharmoniclineradialforceuniformlydistributingalongthegenerator.TheFGMshellequationsofmotion,theHelmholtzequationintheexteriorfluidmediumandth...

简介：Thispaperpresentsahybridgradedelementmodelforthetransientheatconductionprobleminfunctionallygradedmaterials(FGMs).First,aLaplacetransformapproachisusedtohandlethetimevariable.Then,afundamentalsolutioninLaplacespaceforFGMsisconstructed.Next,ahybridgradedelementisformulatedbasedontheobtainedfundamentalsolutionandaframefield.Asaresult,thegradedpropertiesofFGMsarenaturallyreflectedbyusingthefundamentalsolutiontointerpolatetheintra-elementfield.Further,Stefest'salgorithmisemployedtoconverttheresultsinLaplacespacebackintothetime-spacedomain.Finally,theperformanceoftheproposedmethodisassessedbyseveralbenchmarkexamples.Theresultsdemonstratewelltheefficiencyandaccuracyoftheproposedmethod.

简介：Thebendingresponsesoffunctionallygraded(FG)nanobeamswithsimplysupportededgesareinvestigatedbasedonTimoshenkobeamtheoryinthisarticle.TheGurtin-MurdochsurfaceelasticitytheoryisadoptedtoanalyzetheinfluencesofsurfacestressonbendingresponseofFGnanobeam.ThematerialpropertiesareassumedtovaryalongthethicknessofFGnanobeaminpowerlaw.Thebendinggoverningequationsarederivedbyusingtheminimumtotalpotentialenergyprincipleandexplicitformulasarederivedforrotationangleanddeflectionofnanobeamswithsurfaceeffects.IllustrativeexamplesareimplementedtogivethebendingdeformationofFGnanobeam.Theinfluencesoftheaspectratio,gradientindex,andsurfacestressondimensionlessdeflectionarediscussedindetail.

简介：Thetransientfracturebehaviorofafunctionallygradedlayeredstructuresubjectedtoanin-planeimpactloadisinvestigated.Thestudiedstructureiscomposedoftwohomogeneouslayersandafunctionallygradedinterlayerwithacrackperpendiculartotheboundaries.Theimpactloadisappliedonthefaceofthecrack.FouriertransformandLaplacetransformmethodsareusedtoformulatethepresentproblemintermsofasingularintegralequationinLaplacetransformdomain.Consideringvariationsofparameterssuchasthenonhomogeneityconstant,thethicknessratioandthecracklength,thedynamicstressintensityfactors(DSIFs)intimedomainarestudiedandsomemeaningfulconclusionsareobtained.

简介：Thispaperpresentsanexactsolutionofthecracktipfieldinfunctionallygradientmaterialwithexponentialvariationofelasticconstants.ThedimensionlessPoisson'sratiosv0oftheengineeringmaterials(iron,glass...)arefarlessthanone;therefore,neglectingthem,onecansimplifythebasicequationandtheexactsolutioniseasytoobtain.Althoughtheexactsolutionforthecasev0≠0isalsoobtained,itisverycomplicatedandthemainresultisthesamewiththecasev0=0(itwillbedealtwithinAppendixⅦ).Ithasbeenfoundthattheexponentialtermexp(ax+by)intheconstitutiveequationsbecomesexp(ax/2+by/2-kr/2)intheexactsolution.

简介：Wavepropagationanalysisforafunctionallygradednanobeamwithrectangularcross-sectionrestingonvisco-Pasternak'sfoundationisstudiedinthispaper.Timoshenko'sbeammodelandnonlocalelasticitytheoryareemployedforformulationoftheproblem.TheequationsofmotionarederivedusingHamilton'sprincipalsbycalculatingkineticenergy,strainenergyandworkduetoviscoelasticfoundation.Theeffectsofvariousparameterssuchaswavenumber,non-homogeneousindex,nonlocalparameterandthreeparametersoffoundationareperformedonthephasevelocityofthenanobeam.Theobtainedresultsindicatethatsomeparameterssuchasnon-homogeneousindex,nonlocalparameterandwavenumberhavesignificanteffectontheresponseofthesystem.

简介：充满液体的机能上地分级的圆柱的壳的免费颤动特征隐居到有弹性的基础被一个分析方法调查。部分轴、尖的尺寸的有弹性的基础被Pasternak模型代表。壳的运动被代表由一阶砍说明旋转惯性的变丑理论并且横向砍紧张。机能上地分级的圆柱的壳由不锈钢和硅氮化物组成。材料性质以成分的体积部分根据幂定律分布通过厚度连续地变化。管理方程用RayleighRitz方法和一条变化途径被获得。液体被古典潜在的流动理论描述。数字例子被举并且与存在可得到的结果到相比验证现在的方法。充满液体的机能上地分级的圆柱的壳的免费颤动隐居到的图形的摘要有弹性的基础被一个分析方法调查。部分轴、尖的尺寸的有弹性的基础被Pasternak模型代表。壳运动被代表由一阶砍变丑理论。管理方程用RayleighRitz方法被获得。液体被古典潜在的流动理论描述。数字例子被举并且与存在可得到的结果到相比验证现在的方法。

简介：TheSchmidtmethodisadoptedtoinvestigatethefractureproblemofmultipleparallelsymmetricandpermeablefinitelengthmode-IIIcracksinafunctionallygradedpiezoelectric/piezomagneticmaterialplane.Thisproblemisformulatedintodualintegralequations,inwhichtheunknownvariablesarethedisplacementjumpsacrossthecracksurfaces.Inordertoobtainthedualintegralequations,thedisplacementjumpsacrossthecracksurfacesaredirectlyexpandedasaseriesofJacobipolynomials.Theresultsshowthatthestress,theelectricdisplacement,andthemagneticfluxintensityfactorsofcracksdependonthecracklength,thefunctionallygradedparameter,andthedistanceamongthemultipleparallelcracks.Thecrackshieldingefectisalsoobviouslypresentedinafunctionallygradedpiezoelectric/piezomagneticmaterialplanewithmultipleparallelsymmetricmode-IIIcracks.

简介：Thescatteringproblemofanti-planeshearwavesinafunctionallygradedmaterialstripwithanoff-centercrackisinvestigatedbyuseofSchmidtmethod.Thecrackisverticallytotheedgeofthestrip.ByusingtheFouriertransform,theproblemcanbesolvedwiththehelpofapairofdualintegralequationsthattheunknownvariableisthejumpofthedisplacementacrossthecracksurfaces.Tosolvethedualintegralequations,thejumpofthedisplacementacrossthecracksurfaceswasexpandedinaseriesofJacobipolynomials.Numericalexampleswereprovidedtoshowtheeffectsoftheparameterdescribingthefunctionallygradedmaterials,thepositionofthecrackandthefrequencyoftheincidentwavesuponthestressintensityfactorsofthecrack.