简介：Inordertoimprovethemechanicalpropertiesofpolypyrrole,compositesweremadebyelectropolymerizingpolypyrroleinapolyurethanematrix.Polypyrrole/polyurethane（PPY/PU）compositefilmscontainingCLO4-,BF4-orCH3-C6H4-SO3-counterionsweremadeinavarietyofsolventsystemsandcharacterizedbySEM,electronicconductivity,FTIR,andmechanicalproperties.Compositefilmsshowingmuchgreaterfiexibilitythanpurepolypyrrolewereobtained,buttheirelectronicconductivitiesweresubstantiallylower.Measuredeonductivitiesrangedfrom0.001to8S/cm,tensilestrengthsfrom44to592psi,andelongationtofailurefrom3to70%.

简介：在结构的常规基于可靠性的最佳设计，可靠性基于概率假设被计算，并且设计目的和限制被看作确定的。在许多情况中，然而，在那里存在在设计目的和限制功能的一些模糊因素。在这篇论文，模糊可靠性和模糊限制被介绍为把压成薄片的composites建立模糊基于可靠性的最佳模型。方法在这篇论文开发了的例子表演能把考虑给可靠性需求和结构的经济方面。因为模糊reliability-basedoptimum设计是一个“软”的图案，现在的结果为结构的可靠性的有效评估提供新方法论并且带给我们一个其他的最佳设计想法。

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简介：PP/claycompositeswithdifferentdispersions,namely,exfoliateddispersion,intercalateddispersionandagglomeratesandpanicle-likedispersion,werepreparedbydirectmeltintercalationorcompounding.TheeffectofclaydispersiononthecrystallizationandmorphologyofPPwasinvestigatedviaPLM,SAXSandDSC.Experimentalresultsshowthatexfoliatedclaylayersaremuchmoreefficientthanintercalatedclayandagglomeratesofclayinservingasnucleationagentduetothenano-scaledispersionofclay,resultinginadramaticdecreaseincrystalsize(lamellarthicknessandspherulites)andanincreaseofcrystallizationtemperatureandcrystallizationrate.Ontheotherhand,adecreaseofmeltingtemperatureandcrystallinitywasalsoobservedinPP/claycompositeswithexfoliateddispersion,duetothestronginteractionbetweenPPandclay.Comparedwithexfoliatedclaylayers,theintercalatedclaylayershavealessimportanteffectonthecrystallizationandcrystalmorphology.Noeffectisseenforsampleswithagglomeratesandpanicle-likedispersion,inregardtomeltingtemperature,crystallizationtemperature,crystalthicknessandcrystallinity.

简介：Inthispaper,thedispersionandnucleationbehaviorofultrafineparticlesofsilicaandlayeredsilicate(LS)inpoly(ethyleneterephthalate)(PET)matrixareinvestigatedandcharacterizedbyTransmissionElectronMicroscopy(TEM),WideAngleX-rayDiffraction(WAXD),DynamicScanningCalorimetry(DSC),andAtomicForceMicroscopy(AFM).ThesolidprecursorsbasedonsilicaandLSaresuggestedoriginallyforpreparingnanocompositeswithgooddispersionmorphology.Resultsshowthattheinitialsub-micron(1000～500nm)LSparticlesareexfoliatedordispersedintonanometer-scaleparticles(30～70nm)duringtheirpolymerizationwithPETmonomers.Thesedispersednanoparticlesformanorderedmorphologyintheirnucleationandgrowthduringannealingnanocomposites.DSCpatternsrevealthatthedoublemeltingpeaksofannealedPET-LSnanocompositesdisappear,whiletheyhaveshrunkeninPET-silicaones.ThesefindingsstronglydemonstratethatthedispersednanoparticlesacceleratethecrystallizationofPET.ThedispersedLSparticleshavehigherpercolationandnucleationperformancethanthoseofsilica.Thehomogeneousdistributionmorphologyofultrafineparticlesiseasilyobtainedbycontrollingtheloadoftheircorrespondingprecursors.SuchadispersionobviouslyimprovesPETpropertiesinthatitsheatdistortiontemperature(HDT)increasesfrom76℃to103℃,andcrystallizationincreases2～4timesmorethanthatofPET.Especially,thenanocompositefilmskeepthemselvestransparentwhenparticleloadiswithin2wt.%thoughthereare3wt.%orsoofagglomeratedparticlesinthenanocomposites.

简介：Theaimofthepaperistodiscoverthegeneralcreepmechanismsfortheshortfiberreinforcementmatrixcomposites(MMCs)underuniaxialstressstatesandtobuildarelationshipbetweenthemacroscopicsteadycreepbehaviorandthematerialmicrogeometricparameters.Theunitcellmodelswereusedtocalculatethemacroscopiccreepbehaviorwithdifferentmicrogeometricparametersoffibersondifferentloadingdirections.Theinfluenceofthegeometricparametersofthefibersandloadingdirectionsonthemacroscopiccreepbehaviorhadbeenobtained,anddescribedquantitatively.Thematrix/fiberinterfacehadbeenconsideredbyathirdlayer,matrix/fiberinterlayer,intheunitcellswithdifferentcreeppropertiesandthickness.Basedonthenumericalresultsoftheunitcellmodels,astatisticmodelhadbeenpresentedfortheplanerandomly-distributed-fiberMMCs.Thefiberbreakagehadbeentakenintoaccountinthestatisticmodelforitstartsexperimentallyearlyinthecreeplife.Withthedistributionofthegeometricparametersofthefibers,theresultsofthestatisticmodelagreewellwiththeexperiments.Withthestatisticmodel,theinfluenceofthegeometricparametersandthebreakageofthefibersaswellasthepropertiesandthicknessoftheinterlayeronthemacroscopicsteadycreepratehavebeendiscussed.

简介：为angle-interlockwoven的有弹性的行为分析的一个微机械模型陶器的composites在这篇论文被建议。这个模型由在空间，在邻近的纱之间的洞和纱的实际剖面图几何学认为纤维是波动和连续性考虑实际织物结构。基于laminate理论，编织的3D角度联锁的有弹性的性质陶器的composites被预言。交叉的纬的不同数字几乎有一样的有弹性的moduli。陶器的矩阵的厚度在有弹性的moduli上有小效果。当波动比率增加纵的模量减少和另外的幼仔的moduli增加时。在理论预言和试验性的结果之间的好同意在分析编织的3Dangle-interlock的有弹性的性质表明建议模型的可行性陶器的composites。这篇论文的结果验证分析聚酯矩阵composites的方法对编织陶器的composites合适的事实。

简介：Theboundaryelementmethodwasimprovedforthe2Delasticcompositeswithrandomlydistributedinclusions.Thisproblemcanbereducedtoaboundaryintegralequationforamulti-connecteddomain.Further,consideringthematricesofthetractionsanddisplacementsforeachgroupoftheidenticalinclusionwerethesame,aneffectivecomputationalschemewasdesigned,sincetheordersoftheresultingmatrixequationscanbegreatlyreduced.Numericalexamplesindicatethatthisboundaryelementmethodschemeismoreeffectivethantheconventionalmulti-domainboundaryelementmethodforsuchaproblem.Thepresentschemecanbeusedtoinvestigatetheeffectivemechanicalpropertiesofthefiber-reinforcedcomposites.

简介：Inthispaper,thebehavioroftwocollinearcracksinmagneto-electro-elasticcompositematerialunderanti-planeshearstressloadingisstudiedbytheSchmidtmethodforpermeableelectricboundaryconditions.ByusingtheFouriertransform,theproblemcanbesolvedwithasetoftripleintegralequationsinwhichtheunknownvariableisthejumpofdisplacementsacrossthecracksurfaces.Insolvingthetripleintegralequations,theunknownvariableisexpandedinaseriesofJacobipolynomials.Numericalsolutionsareobtained.Itisshownthatthestressfieldisindependentoftheelectricfieldandthemagneticflux.