简介：Theboundaryelementmethodisusedforthemodalanalysisoffreevibrationof2-Dcompositestructuresinthispaper.Sincetheparticularsolutionmethodisusedtotreatthetermsofbodyforces(inertialforces)intheequationofmotion,onlystaticfundamentalsolutionsareneededinsolvingtheproblem.Foranisotropiccantileverbeam,thenumericalresultsobtainedbyusingtheBEMpresentedinthispaperareingoodagreement,withthoseofusingFEMorotherBEM,butthisBEMcanalsobeusedtoanalyzeproblemsforanisotropicmaterials.Forsimplysupportedcompositelaminatedbeams,thecomparisonsofthenumericalresultsobtainedbythismethodwiththeanalyticalresultsobtainedby1-Dlaminatedbeamtheoryindicatethatiftheratiooflength/thicknessisgreaterthan20,theresultsofthetwomethodsareingoodagreement,butiftheratiooflength/thicknessislessthan20,bigerrorswilloccurfor1-Dlaminatedbeamtheory.

简介：Solutionstoapiezoelectrichalf-planewithafixedconductorsurfaceelectrodesubjectedtotwogeneralizedsingularities(linedislocationand/orlineforceandfreecharge)arepresented.Coulombforcesactingonthesingularitiesduetotheboundarypolarizationchargesofmediumandtheinductioncharg-esofconductorelectrodeareanalyzedindetail.Theinteractionbetweenthetwosingularitiesisalsoanalyzednumerically.ResultsshowthatCoulombforceswillbecomeimportantasthefreechargeapproachestheboundaryortwosingularitiesmoveclosely.

简介：PhaseShiftingAndLogicalMoire(PSALM)isakindofcomputerimageprocessingmethodwhichcanbeusedinphasemeasurementandtoobtaintheshape,deformationandstraindistributionofanobject.Thispaperpresentsthestructureandworkingprocedureofa2DphasemeasurementPSALM2Dprogramanditsapplication.Whenanalyzingmoireinterferometricfringes,wecanobtain2Ddistributionofdisplacementandstrain.Whenitisusedinreflectionmoirewecanmeasuretheslopeofaspecimen.SatisfactoryvisualizationandquantitativeresultsaregivenbyPSALM2D.

简介：尽管边界排水量和拖拉是处于在一个非退化的边界点的一个弹性问题的边界条件的独立的地变量，在那里存在在在一条单个边界的边界排水量衍生物和拖拉之间的奇特紧张的明确的关系指。在为2D的一个单个光滑的点的关系的分析表格各向同性的有弹性的问题在这个工作被建立了。由使用关系，单个边界点的位置和未知边界的相应奇特紧张回答变量能被决定priori。因此，未知边界的更适当的形状函数在单个元素回答变量能被构造。一个数字例子证明用发达理论的BEM分析的精确性极大地被增加。

简介：Thenew-typetractionboundaryintegralequationsdevelopedbyHuandwithnohypersingularintegralareappliedtoanalysisof3Dfinitecrackedbodies.Anumericalalgorithmforgeneral3Dproblemsandasemi-analyticaloneforaxisymmetricproblemsarepresented.Someexamplesofthickplatesandcylindricalcolumnsincludingpenny-shapedcrack(s),andrectangularplatesincludinganellipticalcracknormaltothesurfaceareanalyzed.Thecomparisonbetweenpresentresultsandthoseinliteratureshowsthehighaccuracyandeffectivenessofthepresentmethod.

简介：Theboundaryelementmethodforthemodalanalysisoffreevibrationfor3-Danisotropicstructuresusingparticularsolutionshasbeendeveloped.Thecompletepolynomialsofordertwoareusedtoconstructtheparticularsolutionsforgeneralanisotropicmaterials.Thenumericalresultsfor3-Dfreevibra-tionanalysisofanisotropiecantileverbeambythemethodpresentedisingoodagreementwiththeresultsus-ingtheRitztechnique.Foranisotropicmaterials,thenumericalresultscalculatedfromtheproposedmethodareingoodagreementwiththeresultsfromMSC.NASTRAN.

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.

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：thehydroxya-patite粒子的机械性质上的水吸着的损坏效果增强了Bis-GMA/TEGDMA共聚物(HA/Bis-GMA/TEGDMA)用3D被预言了有限房间模型。聚合物矩阵上的可塑剂效果被看作它的幼仔的模量的一个变化。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的影响。压力分发模式被检验了，压力转移模式澄清了。幼仔Bis-GMA/TEGDMA的模量和破裂力量合成也有或没有损坏的考虑用模型被预言。有thedebonding损坏的考虑的以前的结果在对存在文学的好同意是试验性的数据。我们的建议模型和一条其他的途径的防护效果被讨论。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。

简介：Thepresentworkisconcernedwithapenny-shapedDugdalecrackembeddedinaninfinitespaceofone-dimensional(1D)hexagonalquasicrystalsandsubjectedtotwoidenticalaxisymmetrictemperatureloadingsontheupperandlowercracksurfaces.ApplyingDugdalehypothesistothermo-elasticresults,theextentoftheplasticzoneatthecracktipisdetermined.Thenormalstressoutsidetheplasticzoneandcracksurfacedisplacementarederivedintermsofspecialfunctions.Forauniformloadingcase,thecorrespondingresultsarepresentedbysimplifyingtheprecedingresults.Numericalcalculationsarecarriedouttoshowtheinfluenceofsomeparameters.

简介：三维(3D)排干的triaxial压缩和飞机的模拟拉紧的DEM(分离元素方法)测试用一个周期的房间为polydisperse范围的稠密、松开的集会被介绍。在工作，报导、排干的测试被在经常的吝啬的压力条件下面使样品变形建模。排干的行为被显示是类似于出版物理试验性的结果的品质上。主教为中间的主要压力的评价的公式被评估。批评密度的存在被显示独立于起始的收拾行李的密度和紧张条件。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的。一个新显微镜的织物参数被介绍在一般3D织物条件下面把卓见给结构的anisotropy。二个参数描绘压力和分别地独立于种类条件的织物的进化，这被发现。

简介：软事被观察异常粘性行为经常在声学的波浪繁殖由幂定律频率依赖者变细描绘了。最近的十年在为如此的异常粘性行为，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的波浪方程开发各种各样的模型上见证快成长研究。学习是使用修改Szabo的波浪方程模仿一种最近的超声的成像技术的这的目的把临床的amplitudevelocity重建称为具有典型软织物事的胸肿瘤的成像(CARI)。调查在超声的医药成像的质量上在尺寸的效果和肿瘤的位置上被做了。它从数字结果被观察沿着思考的线的健全压力，它显示察觉结果，与尺寸和肿瘤的侧面的位置显然变化，但是几乎仍然是为不同轴的位置的一样。

简介：在这篇论文，为orthotropic板的飞机裂缝问题的压力紧张因素的评估相等参数用一个分数维的二水平的有限元素方法(F2LFEM)被调查。一个orthotropic裂缝问题的一般答案被与各向同性的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。在裂缝板的裂缝尖端的邻居，分数维的几何学概念被介绍完成有类似比率的类似的网孔不到一个并且产生一个无穷小的网孔以便在二邻近的层的僵硬矩阵之间的关系是相等的。在裂缝尖端附近的自由的很多度被转变到概括坐标的一个小集合。数字例子证明这个方法在评估压力紧张因素(SIF)有效、精确。

简介：Thenonlinearbehaviorofacantileveredfluidconveyingpipesubjectedtoprincipalparametricandinternalresonancesisinvestigatedinthispaper.Theflowvelocityisdividedintoconstantandsinusoidaiparts.Thevelocityvalueoftheconstantpartissoadjustedsuchthatthesystemexhibits3:1internalresonancesforthefirsttwomodes.Themethodofmultiplescalesisemployedtoobtaintheresponseofthesystemandasetoffourfirst-ordernonlinearordinary-differentialequationsforgoverningtheamplitudeoftheresponse.TheeigenvaluesoftheJacobianmatrixareusedtoassessthestabilityoftheequilibriumsolutionswithvaryingparameters.Thecodimension2derivedfromthedouble-zeroeigenvaiuesisanalyzedindetail.Theresultsshowthattheresponseamplitudemayundergosaddle-node,pitchfork,Hopf,homoclinicloopandperiod-doublingbifurcationsdependingonthefrequencyandamplitudeofthesinusoidalflow.Whenthefrequencyofthesinusoidalflowequalsexactlyhalfofthefirst-modefrequency,thesystemhasaroutetochaosbyperiod-doublingbifurcationandthenreturnstoaperiodicmotionastheamplitudeofthesinusoidalflowincreases.

简介：Toconsidertheanisotropicdamageinfatigue,animprovedboom-panelmodelispresentedtosimulatearepresentativevolumeelement(RVE)intheframeworkofcontinuumdamagemechanics.TheanisotropicdamagestateoftheRVEisdescribedbythecontinuityextentsofboomsandpanels,whosedamageevolutionsareassumedtobeisotropic.Thenumericalimplementationisproposedonthebasisofdamagemechanicsandthefiniteelementmethod.Finally,theapproachisappliedtothefatiguelifepredictionof2A12-T4aluminiumalloyspecimenundercyclicloadingoftension-torsion.Theresultsindicateagoodagreementwiththeexperimentaldata.