简介：Handlingindustrialpowdersleadstodustemissions.Theseemissionstendtogeneratehumandiseasesorcauseotherenvironmentaleffects.Amultitudeofapparatushasbeendevelopedtoestimatethisdustinessbehaviourofpowders.Twoofthesewell-knownmethodsarepresentedandcomparedwitheachother.Athirdrecentlydevelopedmethodisalsointroduced.

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简介：Basedonelementarygrouptheory,theblockpivotmethodsforsolv-ingtwo-dimensionalelasticfrictionalcontactproblemsarepresentedinthispaper.Itisprovedthatthealgorithmsconvergewithinafinitenumberofstepswhenthefrictioncoefficientis'relativesmall'.Unlikemostmathematicalprogrammingmeth-odsforcontactproblems,theblockpivotmethodspermitmultipleexchangesofbasicandnonbasicvariables.

简介：Inthiswork,dynamiccompositeanalysistruncatedsandwichconicalshells(STCS)withdifferentboundaryconditionsunderlowvelocityimpactwasinvestigatedanalytically,accordinghigherordersandwichpaneltheory.ImpactoccurredatthetopfacesheetandthecontactforcehistoryispredictedusingtwosolutionmodelscalculatedapplyingprincipalofHamiltonbyconsideringthedisplacementcontinuityconditionsbetweenthelayers.Forobtainingthedisplacementandcontactforcehistories,thedifferentialquadraturemethod(DQM)isutilised.Inthisinvestigation,theeffectsoflayerlaminanumber,conesemivertexangle,boundaryconditionsandimpactvelocityontheimpactresponsearestudied.

简介：Inthiswork,dynamiccompositeanalysistruncatedsandwichconicalshells(STCS)withdifferentboundaryconditionsunderlowvelocityimpactwasinvestigatedanalytically,accordinghigherordersandwichpaneltheory.ImpactoccurredatthetopfacesheetandthecontactforcehistoryispredictedusingtwosolutionmodelscalculatedapplyingprincipalofHamiltonbyconsideringthedisplacementcontinuityconditionsbetweenthelayers.Forobtainingthedisplacementandcontactforcehistories,thedifferentialquadraturemethod(DQM)isutilised.Inthisinvestigation,theeffectsoflayerlaminanumber,conesemivertexangle,boundaryconditionsandimpactvelocityontheimpactresponsearestudied.

简介：The6thAsianConferenceonMultibodyDynamics(ACMD2012)hasbeensuccessfullyheldinShanghaiChinaorganizedbyShanghaiJiaoTongUniversity,hostedbytheChineseSocietyofTheoreticalandAppliedMechanics,divisionofdynamicsandcontrol,theJapanSocietyofMechanicalEngineers,theKoreanSocietyofMechanicalEngineers,InternationalFederationforthePromotionofMechanismandMachineScienceandInternationalSteeringCommitteeofAsianConferenceonMultibodyDynamics.

简介：Severaleffectivenumericalmethodsforsolvingtheelasto-plasticcontactproblemswithfrictionarepres-ented.First,adirectsubstitutionmethodisemployedtoimposethecontactconstraintconditionsoncondensedfiniteele-mentequations,thusresultinginareductionbyhalfinthedimensionoffinalgoverningequations.Second,analgorithmcomposedofcontactconditionprobesandelasto-plasticiterationsisutilizedtosolvethegoverningequation,whichdistinguishestwokindsofnonlinearities,andmakesthesolutionunique.Inaddition,Positive-NegativeSequenceModifica-tionMethodisusedtocondensethefiniteelementequationsofeachsubstructureandananalyticalintegrationisintro-ducedtodeterminetheelasto-plasticstatusaftereachtimesteporeachiteration,hencethecomputationalefficiencyisen-hancedtoagreatextent.Finally,severaltestandpracticalexamplesarepressentedshowingthevalidityandversatilityofthesemethodsandalgorithms.

简介：Themulti-scalestructuresofcomplexflowsinchemicalengineeringhavebeengreatchallengestothedesignandscalingofsuchsystems,andmulti-scalemodelingisthenaturalwayinresponse.Particlemethods(PMs)areidealconstituentsandpowerfultoolsofmulti-scalemodels,owingtotheirphysicalfidelityandcomputationalsimplicity.Especially,pseudo-particlemodeling(PPM,Ge&Li,1996;Ge&Li,2003)ismostsuitableformolecularscaleflowpredictionandexplorationoftheoriginofmulti-scalestructures;macro-scalePPM(MaPPM,Ge&Li,2001)andsimilarmodelsareadvantageousformeso-scalesimulationsofflowswithcomplexanddynamicdiscontinuity,whilethelatticeBoltzmannmodelismorecompetentforhomogeneousmediaincomplexgeometries;andmeso-scalemethodssuchasdissipativeparticledynamicsareuniquetoolsforcomplexfluidsofuncertainpropertiesorflowswithstrongthermalfluctuations.Allthesemethodsarefavorableforseamlessinterconnectionofmodelsfordifferentscales.However,asPMsarenotoriginallydesignedaseithertoolsforcomplexityorconstituentsofmulti-scalemodels,furtherimprovementsareexpected.PPMisproposedformicroscopicsimulationofparticle-fluidsystemsasacombinationofmoleculardynamics(MD)anddirectsimulationMonte-Carlo(DSMC).ThecollisiondynamicsinPPMisidenticaltothatofhard-sphereMD,sothatmass,momentumandenergyareconservedtomachineaccuracy.However,thecollisiondetectionprocedure,whichismosttime-consuminganddifficulttobeparallelizedforhard-sphereMD,hasbeengreatlysimplifiedtoaprocedureidenticaltothatofsoft-sphereMD.Actually,thephysicalmodelbehindsuchatreatmentisessentiallydifferentfromMDandismoresimilartoDSMC,butanintrinsicdifferenceisthatinDSMCthecollisionsfollowdesignedstatisticalrulesthatarereflectionoftherealphysicalprocessesonlyinverylimitedcasessuchasdilutegas.PPMisidealforexploringthemechanismofcomplexflowsa

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简介：Whendesigningawavepowerplant,reliableandfastsimulationtoolsarerequired.Computationalfluiddynamics(CFD)softwareprovideshighaccuracybutwithaveryhighcomputationalcost,andinoperational,moderateseastates,linearpotentialflowtheoriesmaybesufficienttomodelthehydrodynamics.Inthispaper,amodelisbuiltinCOMSOLMultiphysicstosolveforthehydrodynamicparametersofapoint-absorbingwaveenergydevice.TheresultsarecomparedwithalinearmodelwherethehydrodynamicalparametersarecomputedusingWAMIT,andtoexperimentalresultsfromtheLysekilresearchsite.Theagreementwithexperimentaldataisgoodforbothnumericalmodels.

简介：Inthispaper,afullythird-orderaccurateprojectionmethodforsolvingtheincompressibleNavier-Stokesequationsisproposed.Toconstructthescheme,acontinuousprojectionprocedureisfirstlypresented.Wethenderiveasufficientconditionforthecontinuousprojectionequationstobetemporallythird-orderaccurateapproximationsoftheoriginalNavier-Stokesequationsbymeansofthelocaltruncation-error-analysistechnique.Thecontinuousprojectionequationsarediscretizedtemporallyandspatiallytothird-orderaccuracyonthestaggeredgrids,resultinginafullythird-orderdiscreteprojectionscheme.Thepossibilitytodesignhigher-orderprojectionmethodsisthusdemonstratedinthepresentpaper.Aheuristicstabilityanalysisisperformedonthisprojectionmethodshowingtheprobabilityofitsbeingstable.Thestabilityofthepresentschemeisfurtherverifiedthroughnumericaltests.Thethird-orderaccuracyofthepresentprojectionmethodisvalidatedbyseveralnumericaltestcases.

简介：Basedontheclassical(matrixtype)input-outputanalysis,atypeofnonlinear(continuoustype)conditionalLeontiefmodel,input-outputequationwereintroduced,aswellasthreecorrespondingquestions,namely,solvability,continuityandsurjectivity,andsomefixedpointandsurjectivitymethodsinnonlinearanalysiswereusedtodealwiththesequestions.Asaresult,themaintheoremsareobtained,whichprovidesomesufficientcriterionstosolveabovequestionsdescribedbytheboundarypropertiesoftheenterprise'sconsumingoperator.

简介：Aninitial-boundaryvalueproblemforshallowequationsystemconsistingofwaterdynamicsequations,silttransportequation,theequationofbottomtopographychange,andofsomeboundaryandinitialconditionsisstudied,theexistenceofitsgeneralizedsolutionandsemidiscretemixedfiniteelement(MFE)solutionwasdiscussed,andtheerrorestimatesofthesemidiscreteMFEsolutionwasderived.Theerrorestimatesareoptimal.

简介：Inthispaper,thenonlinearconjugatemapbasedontheconjugateRackwitz-FiesslerandHasofer-Lind(CHL-RF)methodisusedtoevaluatethereliabilityusingfirstorderreliabilitymethodoftheembeddednanocompositebeam,whichismadefrompolymerreinforcedwithcarbonnanotubs(CNTs).ThestructureissimulatedwithTimoshenkobeammodel.TheMori-Tanakamethodisappliedforobtainingtheeffectivepropertiesofnanocompositebeam.Thesurroundingelasticmediumisconsideredbyspringandshearconstants.UtilisingenergymethodandHamilton'sprincipal,thegoverningequationsareobtained.Usingananalyticalmethod,thebucklingperformancefunctionofstructureisobtained.Theinfluencesofthebasicrandomvariablesincludingthelengthtothicknessratioofbeam(L/h),springconstantandshearconstantoffoundationwithrespecttothevolumefractionofCNTsareinvestigatedonthereliabilityindexofthenanocompositebeamsubjectedtoaxialforceof20GPa.Theresultsindicatedthatthefailureprobabilitiesofthestudiedthenanocompositebeamarethesensitivetothelengthtothicknessofbeam(L/h)andspringconstantoffoundationvariables.

简介：Inthispaper,thenonlinearconjugatemapbasedontheconjugateRackwitz-FiesslerandHasofer-Lind(CHL-RF)methodisusedtoevaluatethereliabilityusingfirstorderreliabilitymethodoftheembeddednanocompositebeam,whichismadefrompolymerreinforcedwithcarbonnanotubs(CNTs).ThestructureissimulatedwithTimoshenkobeammodel.TheMori-Tanakamethodisappliedforobtainingtheeffectivepropertiesofnanocompositebeam.Thesurroundingelasticmediumisconsideredbyspringandshearconstants.UtilisingenergymethodandHamilton'sprincipal,thegoverningequationsareobtained.Usingananalyticalmethod,thebucklingperformancefunctionofstructureisobtained.Theinfluencesofthebasicrandomvariablesincludingthelengthtothicknessratioofbeam(L/h),springconstantandshearconstantoffoundationwithrespecttothevolumefractionofCNTsareinvestigatedonthereliabilityindexofthenanocompositebeamsubjectedtoaxialforceof20GPa.Theresultsindicatedthatthefailureprobabilitiesofthestudiedthenanocompositebeamarethesensitivetothelengthtothicknessofbeam(L/h)andspringconstantoffoundationvariables.