简介：BasedonArnoldi’smethod,aversionofgeneralizedArnoldialgorithmhasbeendevel-opedforthereductionofgyroscopiceigenvalueproblems.Byutilizingtheskewsymmetryofsystemmatrix,averysimplerecurrencescheme,namedgyroscopicArnoldireductionalgorithmhasbeenob-tained,whichisevensimplerthantheLanczosalgorithmforsymmetriceigenvalueproblems.Thecomplexnumbercomputationiscompletelyavoided.Arestarttechniqueisusedtoenablethereductionalgorithmtohaveiterativecharacteristics.Ithasbeenfoundthattherestarttechniqueisnotonlyef-fectivefortheconvergenceofmultipleeigenvaluesbutitalsofurnishesthereductionalgorithmwithatechniquetocheckandcomputemissedeigenvalues.Bycombiningitwiththerestarttechnique,theal-gorithmismadepracticalforlarge-scalegyroscopiceigenvalueproblems.Numericalexamplesaregiv-entodemonstratetheeffectivenessofthemethodproposed.

简介：Asix-variablegeometricalnonlinearsheardeformationlaminatedtheoryispresentedbywhichnormalstressandstraindistributioncanbecalculated.Byconsideringsomeaffectivefactorsthatwereneglectedunderthefinitedeformationcondition,animprovedyonKarmangeometricalnon-lineardeformation-strainrelationisusedforlargedeformationanalysis.Afteranalyzingthebendingproblemoflaminatedplates,andcomparingitwith3-DelasticitysolutionsandJ.N.Reddyfive-vari-ablesimplehigher-ordersheardeformationlaminatedtheory,wecanconcludethatasatisfactorycal-culationprecisionhasbeenachieved,whichshowsthatitisespeciallysuitableforthecalculationintheconditionoflargedeformationandthelaminatedthickplateanalysis.

简介：Inthispaper,anewzigzagmethodforplatestructuresandageneticalgorithm(GA)ofdynamicsourceseedspacesaredevelopedandacombinationofthemisusedtodealwithlargescalebuilt-upstructuraloptimization.ThenewGAcombinedwiththezigzagmethodcanworkefficientlywhencopingwithlargescalestructuraloptimizationincludeddisplacementandstressconstraints.ExamplesshowthatthisGAisrobustandcanbeusedformanycomplexstructuraloptimizationproblems.

简介：Thecomputationalefficiencyofnumericalsolutionoflinearalgebraicequationsinfiniteelementscanbeimprovedintowwqys.Oneistodecreasethefill-innumbers,whicharenewnon-ze-ronumbersinthematrixofglobalstiffnessgeneratedduringtheprocessofelimination.Theotheristoreducethecomputationaloperationofmultiplyingarealnumberbyzero.Basedonthefactthattheorderofeliminationcandeterminehowmanyfill-innumbersshouldbegenerated,wepresentanewmethodforoptimizationofnumberingnodes.Thismethodisquitedifferentfrombandwidthoptimization.Fill-innumberscanbedecreasedinalargescalebytheuseofthismethod.Thebi-factorizationmethodisadotedtoavoidmultiplyingrealnumbersbyzero.Forlargescalefiniteelementanalysis,themethodpresentedinthispaperismoreefficientthanthetraditionalLDLTmethod.

简介：Thesingularboundarymethod(SBM)isarecentmeshlessboundarycollocationmethodthatremediestheperplexingdrawbackoffictitiousboundaryinthemethodoffundamentalsolutions(MFS).Thebasicideaistousetheoriginintensityfactortoeliminatesingularityofthefundamentalsolutionatsource.Themethodhassofarbeenappliedsuccessfullytothepotentialandelasticityproblems.However,theSBMsolutionforlarge-scaleproblemshasbeenhinderedbytheoperationcountofO(N~3)withdirectsolversorO(N~2)withiterativesolvers,aswellasthememoryrequirementofO(N~2).Inthisstudy,thefirstattemptwasmadetocombinethefastmultipolemethod(FMM)andtheSBMtosignificantlyreduceCPUtimeandmemoryrequirementbyonedegreeofmagnitude,namely,O(N).Basedonthecomplexvariablerepresentationoffundamentalsolutions,theFMM-SBMformulationsforbothdisplacementandtractionwerepresented.Numericalexampleswithuptohundredsofthousandsofunknownshavesuccessfullybeentestedonadesktopcomputer.TheseresultsclearlyillustratedthattheproposedFMM-SBMwasveryefficientandpromisinginsolvinglarge-scaleplaneelasticityproblems.

简介：Thispaperstudiesthedynamicbehavioroflargedeformationofsphericalshellsimpactedbyaflat-nosedmissile.Byusingisometrictransformations,thedeformationmodesaregiven.OnthebasisofPerzyna-Symondsviscoplasticconstitutiveequations,themotionequationsoftheshellsareobtainedbyrigid-viscoplasticvariationalprinciple.Acomparisonmadebetweenthenumericalresultsandexperimentalonesindicatesthatthetwogroupsofresultsareinconformitywitheachother.

简介：ExplicitexpressionsofMori-Tanaka’stensorforatransverselyisotropicfiberreinforcedUDcompositearepresented.Closed-formformulaefortheeffectiveelasticpropertiesofthecompositeareobtained.Ina3Dsense,theresultingcompliancetensorofthecompositeissymmetric.Nevertheless,the2DcompliancetensorbasedonadeterioratedMori-Tanaka’stensorisnotsymmetric.Noristhecompliancetensordefineduponadeteriorated2DEshelby’stensor.Thein-planeeffectiveelasticpropertiesgivenbythosethreeapproachesaredifferent.AdetailedcomparisonbetweenthepredictedresultsobtainedfromthoseapproacheswithexperimentaldataavailableforanumberofUDcompositesismade.更多还原

简介：Anexplicitfull-fieldexpressionoftheGreen’sfunctionsforanisotropicpiezoeleetricbimateri-alswithaslippinginterfaceisderived.Whentheelectro-elasticsingularityreducestoapraydislocationindisplacementandelectricpotential,interactionenergy,betweenthedislocationandthebimaterialsisobtainedexplicitlywhilethegeneralizedforceonthedisloeationisgiveninarealformwhiehisalsovalidfordegener-atematerials.Theinvestigationdemonstratesthatthehoundaryconditionsatlheslippinginterfacebetweentwopiezoelectricmaterialswillexertaprominentinfluenceonthemobilityofthedislocation.

简介：Inthispaper,afiniteelementmethodisdevelopedtonumericallyevaluatetheshearcoefficientofTimoshenko'sbeamwithmultiplyconneetedcrosssection.Withfocusonanalyzingshearstressesdistributedattheneutralaxisofthebeam,animproveddefinitionoftheshearcoefficientispresented.Basedonthisdefinition,aGalerkin-typefiniteelementformulationisproposedtoanalyzetheshearstressesandsheardeflections.Numericalsolutionsoftheexamplesforsometypicalcross-sectionsarecomparedwiththetheoreticalresults.TheshearcoefficientoftowersectionsoftheTsingMaBridgeiscalculatedbyuseoftheproposedapproach,sothatthefiniteelementmodelingofthebridgecanbedevelopedwiththeaccuratevaluesofthesectionalproperties.

简介：ShouwenYu,emeritusProfessorofAppliedMechanicsatTsinghuaUniversity,wasbornonMay4,1939inXianyouCounty,FujianProvinceofChina.From1955to1958,hestudiedasanundergraduate

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。