简介:Theconceptofcombiningmetallichoneycombwithfoldedthinmetallicsheets(corrugation)toconstructanovelcoretypeforlightweightsandwichstructuresisproposed.Thehoneycomb–corrugationhybridcoreismanufacturedbyfillingtheintersticesofaluminumcorrugationswithprecision-cuttrapezoidalaluminumhoneycombblocks,bondedtogetherusingepoxyglue.Theperformanceofsuchhybrid-coredsandwichpanelssubjectedtoout-of-planecompression,transverseshear,andthree-pointbendingisinvestigated,bothexperimentallyandnumerically.Thestrengthandenergyabsorptionofthesandwicharedramaticallyenhanced,comparedtothoseofasandwichwitheitheremptycorrugationorhoneycombcore.Theenhancementisinducedbythebeneficialinteractioneffectsofhoneycombblocksandfoldedpanelsonimprovedbucklingresistanceaswellasalteredcrushingmodesatlargeplasticdeformation.Thepresentapproachprovidesaneffectivemethodtofurtherimprovethemechanicalpropertiesofconventionalhoneycomb-coredsandwichconstructionswithlowrelativedensities.
简介:Experimentswereconductedtostudythegenerationofaircoreanditseffectontheoutflowshapeanddischargeinacylindricalwatertankwithabottomwell-designedoutlet.Dependingonthestagesoftheaircoreinthetank,theoutflowshapecanvaryfromasmoothwaterjettoasmoothspindleshapewithair-core,andtowatersprays.Thediameterofthenozzlesizealsohasinfluenceontheoutflowpattern.Theexistenceofthepenetratedaircorecandramaticallyreducetheoutflowdischarge,withthedischargecoefficientdecreasingwiththenozzlediameter.
简介:界面的脱臼可以有相应于的一个传播核心一弱砍接口的抵抗。在这份报纸,一个圆锥形的模型被建议在各向异性的bimaterials模仿界面的脱臼的传播核心。由Stroh形式主义和草地功能,有弹性的地的分析表达式为如此的脱臼被推出。作为一个例子拿Cu/Nbbimaterial,方法的精确性和效率被接口条件很好验证,这被表明,一个传播核心能极大地与紧缩的核心相比在界面的脱臼附近减少压力紧张,并且传播核心区域附近的有弹性的地与压缩核心显著地不同,当他们对是的一个地点不太敏感时,1.5预定核心宽度离开传播核心的中心。
简介:Theeffectofthefacethicknesstocoreheightratioondifferentmulti-layerpyramidalcoresandwichcolumnsunderin-planecompressionisinvestigatedtheoreticallyandnumerically.Numericalsimulationisingoodagreementwiththeory.Resultsindicatethatonespecifiedfacethicknesstocoreheightratiocorrespondstooneoptimumlayernumberofmulti-layerpyramidalcoresandwichcolumnsinconsiderationofengineeringapplication.Thisresultcanguidethesandwichstructuredesign.
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简介:TiO2@ZrO2@Y2O3:有coremultishell结构的Eu3+合成粒子通过layer-by-layer(LBL)的联合被综合自己组装方法和一个solgel过程。获得的样品与扫描电子被描绘显微镜学(SEM),传播电子显微镜学(TEM),X光检查光电子光谱学(XPS),X光检查衍射(XRD),和荧光spectrophotometry。结果证明合成粒子有coremultishell结构,球形的形态学,和狭窄的尺寸分布。TiO2核心上的ZrO2层的存在能有效地阻止在TiO2核心和Y2O3壳之间的反应;为在在TiO2@ZrO2@Y2O3的TiO2核心和Y2O3壳之间的反应的温度:Eucoremultishell黄磷能被300提高
简介:hard-core/soft-shell钙碳酸盐(CaCO3)的合成/poly(甲基methacrylate)(PMMA)混合结构化的nanoparticles(<100nm)由把分裂成原子的微乳液聚合,过程被报导。聚合物链通过acoupling代理人的使用被抛锚到nano-CaCO3的表面上,triethoxyvinylsilane(TEVS)。铵persulfate(APS),钠dodecyl硫酸盐(SDS)和n-pentanol分别地被用作开始者,表面活化剂和cosurfactant。coreshell乳胶粒子的聚合机制被讨论。由PMMA的nano-CaCO3的封装用一台传播电子显微镜(TEM)被证实。coreshell粒子的grafting百分比被thermogravimetric分析(TGA)调查。nano-CaCO3/PMMAcoreshell粒子被Fourier变换描绘红外线(FTIR)光谱学和微分扫描热量测定(DSC)。FTIR结果在nano-CaCO3粒子和PMMA的接口揭示了一个强壮的相互作用的存在,它成功地暗示聚合物链是grafted到通过联合代理人的连接的nano-CaCO3粒子的表面上。另外,TGA和DSC结果与纯nano-PMMA的相比显示了coreshell材料的热稳定性的改进。nano-CaCO3/PMMA粒子被混合进聚丙烯(PP)矩阵由融化处理。它能也用扫描PMMA锁住的电子显微镜学(SEM)被观察grafted在聚合物矩阵(PP矩阵)防碍到CaCO3nanoparticles上CaCO3的聚集并且因此与PP矩阵改进CaCO3nanoparticles的相容性。