简介:ApplyingLagrange–Germain'stheoryofelasticthinplatesandHamiltonianformulation,thedynamicsofcantileverplatesandtheproblemofitsvibrationcontrolarestudied,andageneralsolutionisfinallygiven.BasedonHamiltonianandLagrangiandensityfunction,wecanobtaintheflexuralwaveequationoftheplateandtherelationshipbetweenthetransverseandthelongitudinaleigenvalues.Basedoneigenfunctionexpansion,dispersionequationsofpropagationmodeofcantileverplatesarededuced.Bysatisfyingtheboundaryconditionsofcantileverplates,thenaturalfrequenciesofthecantileverplatestructurecanbegiven.Then,analyticsolutionoftheprobleminplatestructureisobtained.Anhybridwave/modecontrolapproach,whichisbasedonbothindependentmodalspacecontrolandwavecontrolmethods,isdescribedandadoptedtoanalyzetheactivevibrationcontrolofcantileverplates.Thelow-order(controlledbymodalcontrol)andthehigh-order(controlledbywavecontrol)frequencyresponseofplatesarebothimproved.Thecontrolspilloverisavoidedandtherobustnessofthesystemisalsoimproved.Finally,simulationresultsareanalyzedanddiscussed.
简介:Theseriescomposedbybeammodefunctionisusedtoapproximatethedisplacementfunctionofconstraineddampingoflaminatedcantileverplates,andthetransversedeformationoftheplateonwhichaconcentratedforceisactediscalculatedusingtheprincipleofvirtualwork.BysolvingLagrange'sequation,thefrequenciesandmodellossfactorsoffreevibrationoftheplateareobtained,thenthetransientresponseofconstraineddampingoflaminatedcantileverplateisobtained,whentheconcentratedforceiswithdrawnsuddenly.Thetheoreticalcalculationsarecomparedwiththeexperimentaldata,theresultsshow:boththefrequenciesandtheresponsetimeoftheoreticalcalculationanditsvariationallawwiththeparametersofthedampinglayerareidenticalwithexperimentalresults.Also,theresponsetimeofsteelcantileverplate,unconstraineddampingcantileverplateandconstraineddampingcantileverplatearebroughtintocomparison,whichshowsthattheconstraineddampingstructurecaneffectivelysuppressthevibration.
简介:扣环/脆裂声并且弯曲并且为伸臂联合矩形的软铁磁性的盘子magneto-elastic-plastic相互作用的行为的分析被介绍。为塑料从铁磁性的盘子,薄盘子的弄弯并且弯曲的理论,协定收益标准和增长理论的变化原则基于磁性的力量的表示变丑,我们建立数字代码到份量上模仿行为非线性地由有限元素方法的多地联合问题。与扣环/脆裂声并且弯曲的现象一起,或偏转的典型曲线对应用磁场的大小数字地正在被显示,批评大量扣环/脆裂声,并且塑料变丑的影响和这些批评负担上的板的宽度,与应用磁场的大小膨胀的塑料区域,以及板的偏转配置的发展数字地在案例研究被获得。
简介:Bygivingupanyassumptionsaboutdisplacementmodelsandstressdistribution,themixedstateHamiltonequationfortheaxisymmetricproblemofthethicklaminatedclosedcantilevercylindricalshellsisestablished.Anidenticalanalyticalsolutionisobtainedforthethin,moderatelythickandthicklaminatedclosedcantilevercylindricalshells.Allequationsofelasticitycanbesatis-fied,andallelasticconstantscanbetakenintoaccount.
简介:Vibrationmodeoftheconstraineddampingcantileverisbuiltupaccordingtothemodesuperpositionoftheelasticcantileverbeam.ThecontrolequationoftheconstraineddampingcantileverbeamisthenderivedusingLagrange'sequation.Dynamicresponseoftheconstraineddampingcantileverbeamisobtainedaccordingtotheprincipleofvirtualwork,whentheconcentratedforceissuddenlyunloaded.Frequenciesandtransientresponseofaseriesofconstraineddampingcantileverbeamsarecalculatedandtested.Influenceofparametersofthedampinglayerontheresponsetimeisanalyzed.Analyitcalandexperimentalapproachesareusedforverification.Theresultsshowthatthemethodisreliable.
简介:Dynamicmodelingofacantileverbeamunderanaxialmovementofitsbasementispresent-ed.ThedynamicequationofmotionforthecantileverbeamisestablishedbyusingKane’sequationfirstandthensimplifiedthroughtheRayleigh-Ritzmethod.Comparedwiththeoldermodelingmethod,whichlineari-zesthegeneralizedinertiaforcesandthegeneralizedactiveforces,thepresentmodehngtakesthecoupledcubicnonlinearitiesofgeometricalandinertialtypesintoconsideration.Themethodofmultiplescalesisusedtodirectlysolvethenonlineardifferentialequationsandtoderivethenonlinearmodulationequationfortheprincipalparametricresonance.Theresultsshowthatthenonlinearinertiatermsproduceasofteningeffectandplayasignificantroleintheplanarresponseofthesecondmodeandthehigherones.Ontheotherhand,thenonlineargeometrictermsproduceahardeningeffectanddominatetheplanarresponseofthefirstmode.Thevalidityofthepresentmodelingisclarifiedthroughthecomparisonsofitscoefficientswiththoseexperimentallyverifiedinpreviousstudies.
简介:Owingtotheabsenceofproperanalyticalsolutionofcantileverbeamsforcouplestress/straingradientelas-to-plastictheory,experimentalstudiesofthecantileverbeaminthemicro-scalearenotsuitableforthedeterminationofmateriallength-scale.Basedonthecouplestresselasto-plas-ticity,ananalyticalsolutionofthincantileverbeamsisfirstlypresented,andthesolutioncanberegardedasanextensionoftheelasticandrigid-plasticsolutionsofpurebendingbeam.Acomparisonwithnumericalresultsshowsthatthecurrentanalyticalsolutionisreliableforthecaseofσ0(?)H(?)E,whereσ0istheinitialyieldstrength,HisthehardeningmodulusandEistheelasticmodulus.Fortunately,theabovementionedconditioncanbesatisfiedformanymetalmaterials,andthusthesolutioncanbeusedtodeterminethemateriallength-scaleofmicro-structuresinconjunctionwiththeexperimentofcantileverbeamsinthemicro-scale.
简介:StraightandBentnano-cantileverspecimensarerespectivelyproposedtoinvestigatethesingle-modeandmixed-modecrackinitiationattheCu/Siinterfaceedgeinnanoscalecomponents.Withaminuteloadingapparatus,allnanoscalesamplesareinsituloadedandobserved.Numericalanalysisisemployedtoacquirethecriticalinterfacialstressdistributionsduringcrackinitiation.ThestressconcentrationregionsneartheedgeofCu/Siinterfaceinallspecimensarewithinthescaleof100nm,andthecriticalnormalandshearstresseshaveacircularrelationinnanoscalecomponents,whichrepresentsthefracturecriterionoftheinterfaceinnanoscalecomponents.
简介:Thispaperdealswithfinitedeformationproblemsofcantileverbeamwithvariablesec-tionundertheactionofarbitrarytransverseloads.Bytheuseofamethodofvariablereplacement,thenonlineardifferentialequationwithvariedcoefficientfortheproblemcanbetransformedintoanequationwithvariableseparable.Theexactsolutioncanbeobtainedbytheintegrationmethod.Someexamplesaregiveninthepaper,andtheresultsoftheseexamplesshowthatthisexactsolutionincludestheexistingsolutionsinreferencesasspecialcases.