学科分类
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19 个结果
  • 简介:Thenew-typetractionboundaryintegralequationsdevelopedbyHuandwithnohypersingularintegralareappliedtoanalysisof3Dfinitecrackedbodies.Anumericalalgorithmforgeneral3Dproblemsandasemi-analyticaloneforaxisymmetricproblemsarepresented.Someexamplesofthickplatesandcylindricalcolumnsincludingpenny-shapedcrack(s),andrectangularplatesincludinganellipticalcracknormaltothesurfaceareanalyzed.Thecomparisonbetweenpresentresultsandthoseinliteratureshowsthehighaccuracyandeffectivenessofthepresentmethod.

  • 标签: principal integral crack stress INTENSITY factor
  • 简介:Theboundaryelementmethodforthemodalanalysisoffreevibrationfor3-Danisotropicstructuresusingparticularsolutionshasbeendeveloped.Thecompletepolynomialsofordertwoareusedtoconstructtheparticularsolutionsforgeneralanisotropicmaterials.Thenumericalresultsfor3-Dfreevibra-tionanalysisofanisotropiecantileverbeambythemethodpresentedisingoodagreementwiththeresultsus-ingtheRitztechnique.Foranisotropicmaterials,thenumericalresultscalculatedfromtheproposedmethodareingoodagreementwiththeresultsfromMSC.NASTRAN.

  • 标签: BOUNDARY ELEMENT method ANISOTROPIC structure particular
  • 简介:ThisinvestigationpresentstheGreenfunctionsforadecagonalquasicrystallinematerialwithaparabolicboundarysubjecttoalineforceandalinedislocationbymeansofthecomplexvariablemethod.ThesurfaceGreenfunctionsaretreatedasaspecialcase,andtheexplicitexpressionsofdisplacementsandhoopstressattheparabolicboundaryarealsogiven.Finally,thestressesanddisplacementsinducedbyaphononlineforceactingattheoriginofthelowerhalf-spacearepresented.

  • 标签: 十边形准晶体 抛物线 格林函数 保角映射
  • 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.

  • 标签: ROLLER bearing TRACTION sub-element METHOD elastic
  • 简介:为angle-interlockwoven有弹性行为分析个微机械模型陶器composites在这篇论文被建议。这个模型由在空间,在邻近纱之间洞和纱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3D角度联锁有弹性性质陶器composites被预言。交叉不同数字几乎有有弹性moduli。陶器矩阵厚度在有弹性moduli上有小效果。当波动比率增加纵模量减少和另外幼仔moduli增加时。在理论预言和试验性结果之间好同意在分析编织3Dangle-interlock有弹性性质表明建议模型可行性陶器composites。这篇论文结果验证分析聚酯矩阵composites方法对编织陶器composites合适事实。

  • 标签: 陶瓷复合材料 弹性行为分析 几何参数 交叉断面几何
  • 简介:thehydroxya-patite粒子机械性质上水吸着损坏效果增强了Bis-GMA/TEGDMA共聚物(HA/Bis-GMA/TEGDMA)用3D被预言了有限房间模型。聚合物矩阵上可塑剂效果被看作它幼仔模量个变化。三个不同房间模型被用来决定在debondingdamage上改变粒子内容,分裂期间力量和潮湿集中影响。压力分发模式被检验了,压力转移模式澄清了。幼仔Bis-GMA/TEGDMA模量和破裂力量合成也有没有损坏考虑用模型被预言。有thedebonding损坏考虑以前结果在对存在文学好同意是试验性数据。我们建议模型和条其他途径防护效果被讨论。FCC房间模型也被扩大了预言批评负担为损坏并且undamaged合成题目到3点曲折测试。

  • 标签: 水吸附 牙齿复合材料 界面松懈工艺 有限元法 单元细胞模型
  • 简介:这篇论文介绍各向异性损坏理论应用程序给形成A12024T3铝合金表限制图学习。在限制铝板结构紧张预言,个有限元素房间模型被构造了。房间模型由二个阶段,铝合金矩阵和金属化合簇组成。铝合金矩阵材料行为与充分联合elasto塑料损坏被描述组成方程。金属化合簇被假定有弹性、易碎。由改变拉长比率,在二轴拉长下面的表限制紧张被使用建议necking标准预言了。预言在对试验性调查结果好同意。而且,有限元素房间模型能为理解铝合金显微镜损坏机制提供信息。如果材料损坏效果在形成学习表金属被忽略,限制紧张在评价上可以结果。

  • 标签: 成形极限图 各向异性损伤 有限元法 极限应力
  • 简介:三维(3D)排干triaxial压缩和飞机模拟拉紧DEM(分离元素方法)测试用个周期房间为polydisperse范围稠密、松开集会被介绍。在工作,报导、排干测试被在经常吝啬压力条件下面使样品变形建模。排干行为被显示是类似于出版物理试验性结果品质上。主教为中间主要压力评价公式被评估。批评密度存在被显示独立于起始收拾行李密度和紧张条件。不同失败标准基于DEM模拟结果被比较了,并且Lade标准被发现是最适当个新显微镜织物参数被介绍在3D织物条件下面把卓见给结构anisotropy。二个参数描绘压力和分别地独立于种类条件织物进化,这被发现。

  • 标签: 数字高程模型 平面应变 排水试验 模型模拟 三轴压缩 颗粒物质
  • 简介:软事被观察异常粘性行为经常在声学波浪繁殖由幂定律频率依赖者变细描绘了。最近十年在为如此异常粘性行为,礼品,作者们经由积极部分衍生物在哪个之中建议了修改Szabo波浪方程开发各种各样模型上见证快成长研究。学习是使用修改Szabo波浪方程模仿种最近超声成像技术目的把临床amplitudevelocity重建称为具有典型软织物事胸肿瘤成像(CARI)。调查在超声医药成像质量上在尺寸效果和肿瘤位置上被做了。它从数字结果被观察沿着思考线健全压力,它显示察觉结果,与尺寸和肿瘤侧面的位置显然变化,但是几乎仍然是为不同轴位置样。

  • 标签: 超声成像 波动方程 应用程序 软物质 率相关 粘性耗散
  • 简介:Solutionstoapiezoelectrichalf-planewithafixedconductorsurfaceelectrodesubjectedtotwogeneralizedsingularities(linedislocationand/orlineforceandfreecharge)arepresented.Coulombforcesactingonthesingularitiesduetotheboundarypolarizationchargesofmediumandtheinductioncharg-esofconductorelectrodeareanalyzedindetail.Theinteractionbetweenthetwosingularitiesisalsoanalyzednumerically.ResultsshowthatCoulombforceswillbecomeimportantasthefreechargeapproachestheboundaryortwosingularitiesmoveclosely.

  • 标签: Green’s FUNCTIONS COULOMB FORCES LINE DISLOCATION
  • 简介:PhaseShiftingAndLogicalMoire(PSALM)isakindofcomputerimageprocessingmethodwhichcanbeusedinphasemeasurementandtoobtaintheshape,deformationandstraindistributionofanobject.Thispaperpresentsthestructureandworkingprocedureofa2DphasemeasurementPSALM2Dprogramanditsapplication.Whenanalyzingmoireinterferometricfringes,wecanobtain2Ddistributionofdisplacementandstrain.Whenitisusedinreflectionmoirewecanmeasuretheslopeofaspecimen.SatisfactoryvisualizationandquantitativeresultsaregivenbyPSALM2D.

  • 标签: logical MOIRE phase SHIFTING IMAGE PROCESSING
  • 简介:Theboundaryelementmethodisusedforthemodalanalysisoffreevibrationof2-Dcompositestructuresinthispaper.Sincetheparticularsolutionmethodisusedtotreatthetermsofbodyforces(inertialforces)intheequationofmotion,onlystaticfundamentalsolutionsareneededinsolvingtheproblem.Foranisotropiccantileverbeam,thenumericalresultsobtainedbyusingtheBEMpresentedinthispaperareingoodagreement,withthoseofusingFEMorotherBEM,butthisBEMcanalsobeusedtoanalyzeproblemsforanisotropicmaterials.Forsimplysupportedcompositelaminatedbeams,thecomparisonsofthenumericalresultsobtainedbythismethodwiththeanalyticalresultsobtainedby1-Dlaminatedbeamtheoryindicatethatiftheratiooflength/thicknessisgreaterthan20,theresultsofthetwomethodsareingoodagreement,butiftheratiooflength/thicknessislessthan20,bigerrorswilloccurfor1-Dlaminatedbeamtheory.

  • 标签: COMPOSITE structure BOUNDARY ELEMENT METHOD particular
  • 简介:InallthearticlesinActaMechanicaSolidaSinica,Volume31,Issues1-4thecopyrightisincorrectlydisplayedas"TheChineseSocietyofTheoreticalandAppliedMechanicsandTechnology"whereitshouldbe"TheChineseSocietyofTheoreticalandAppliedMechanics".

  • 标签: CORRECTION ACTA MECHANICA solida COPYRIGHT
  • 简介:在这篇论文,为orthotropic板飞机裂缝问题压力紧张因素评估相等参数用个分数维二水平有限元素方法(F2LFEM)被调查。个orthotropic裂缝问题般答案被与各向同性裂缝问题吸收这个问题获得,并且在F2LFEM作为全球插值功能被采用。在裂缝板裂缝尖端邻居,分数维几何学概念被介绍完成有类似比率类似的网孔不到个并且产生个无穷小网孔以便在二邻近僵硬矩阵之间关系是相等。在裂缝尖端附近自由很多度被转变到概括坐标的个小集合。数字例子证明这个方法在评估压力紧张因素(SIF)有效、精确。

  • 标签: 平面裂缝 分形有限元 应力密度因子 固体力学
  • 简介:尽管边界排水量和拖拉是处于在个非退化边界点个弹性问题边界条件独立地变量,在那里存在在在条单个边界边界排水量衍生物和拖拉之间奇特紧张明确关系指。在为2D个单个光滑关系分析表格各向同性有弹性问题在这个工作被建立了。由使用关系,单个边界点位置和未知边界相应奇特紧张回答变量能被决定priori。因此,未知边界更适当形状函数在单个元素回答变量能被构造。个数字例子证明用发达理论BEM分析精确性极大地被增加。

  • 标签: 边界移位牵引 不连续性 奇异边界点 等方弹性问题 弱奇点
  • 简介:Thepresentworkisconcernedwithapenny-shapedDugdalecrackembeddedinaninfinitespaceofone-dimensional(1D)hexagonalquasicrystalsandsubjectedtotwoidenticalaxisymmetrictemperatureloadingsontheupperandlowercracksurfaces.ApplyingDugdalehypothesistothermo-elasticresults,theextentoftheplasticzoneatthecracktipisdetermined.Thenormalstressoutsidetheplasticzoneandcracksurfacedisplacementarederivedintermsofspecialfunctions.Forauniformloadingcase,thecorrespondingresultsarepresentedbysimplifyingtheprecedingresults.Numericalcalculationsarecarriedouttoshowtheinfluenceofsomeparameters.

  • 标签: 裂纹尖端塑性区 无限空间 币形裂纹 一维 加载 QC
  • 简介:Thenonlinearbehaviorofacantileveredfluidconveyingpipesubjectedtoprincipalparametricandinternalresonancesisinvestigatedinthispaper.Theflowvelocityisdividedintoconstantandsinusoidaiparts.Thevelocityvalueoftheconstantpartissoadjustedsuchthatthesystemexhibits3:1internalresonancesforthefirsttwomodes.Themethodofmultiplescalesisemployedtoobtaintheresponseofthesystemandasetoffourfirst-ordernonlinearordinary-differentialequationsforgoverningtheamplitudeoftheresponse.TheeigenvaluesoftheJacobianmatrixareusedtoassessthestabilityoftheequilibriumsolutionswithvaryingparameters.Thecodimension2derivedfromthedouble-zeroeigenvaiuesisanalyzedindetail.Theresultsshowthattheresponseamplitudemayundergosaddle-node,pitchfork,Hopf,homoclinicloopandperiod-doublingbifurcationsdependingonthefrequencyandamplitudeofthesinusoidalflow.Whenthefrequencyofthesinusoidalflowequalsexactlyhalfofthefirst-modefrequency,thesystemhasaroutetochaosbyperiod-doublingbifurcationandthenreturnstoaperiodicmotionastheamplitudeofthesinusoidalflowincreases.

  • 标签: 非线性动力学 分歧 稳定性 液-固相互作用 内谐振 混沌
  • 简介:Toconsidertheanisotropicdamageinfatigue,animprovedboom-panelmodelispresentedtosimulatearepresentativevolumeelement(RVE)intheframeworkofcontinuumdamagemechanics.TheanisotropicdamagestateoftheRVEisdescribedbythecontinuityextentsofboomsandpanels,whosedamageevolutionsareassumedtobeisotropic.Thenumericalimplementationisproposedonthebasisofdamagemechanicsandthefiniteelementmethod.Finally,theapproachisappliedtothefatiguelifepredictionof2A12-T4aluminiumalloyspecimenundercyclicloadingoftension-torsion.Theresultsindicateagoodagreementwiththeexperimentaldata.

  • 标签: 吊杆面板模型 各向异性的损坏 疲劳 紧张扭转 生活预言