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

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

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

简介：InallthearticlesinActaMechanicaSolidaSinica,Volume31,Issues1-4thecopyrightisincorrectlydisplayedas"TheChineseSocietyofTheoreticalandAppliedMechanicsandTechnology"whereitshouldbe"TheChineseSocietyofTheoreticalandAppliedMechanics".

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

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

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