学科分类
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13 个结果
  • 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.

  • 标签: 振动控制 悬臂板 HAMILTON 独立模态空间控制 混合 振动主动控制
  • 简介:有多重时间延期的一个灵活伸臂盘子的活跃控制用分离最佳的控制方法被调查。有多重时间延期的一个控制器被介绍。在这个控制器,时间延期效果在整个控制设计和没有近似在动态系统的数学模型被合并,假设在控制器推导被做,因此系统稳定性容易被保证。而且,这个控制器为两小时间延期和大时间延期是可得到的。建议控制器的可行性和效率这份报纸最后通过数字模拟被验证。

  • 标签: 柔性悬臂 多倍时间滞后 离散优化控制 时间延迟效应
  • 简介:Theseriescomposedbybeammodefunctionisusedtoapproximatethedisplacementfunctionofconstraineddampingoflaminatedcantileverplates,andthetransversedeformationoftheplateonwhichaconcentratedforceisactediscalculatedusingtheprincipleofvirtualwork.BysolvingLagrange'sequation,thefrequenciesandmodellossfactorsoffreevibrationoftheplateareobtained,thenthetransientresponseofconstraineddampingoflaminatedcantileverplateisobtained,whentheconcentratedforceiswithdrawnsuddenly.Thetheoreticalcalculationsarecomparedwiththeexperimentaldata,theresultsshow:boththefrequenciesandtheresponsetimeoftheoreticalcalculationanditsvariationallawwiththeparametersofthedampinglayerareidenticalwithexperimentalresults.Also,theresponsetimeofsteelcantileverplate,unconstraineddampingcantileverplateandconstraineddampingcantileverplatearebroughtintocomparison,whichshowsthattheconstraineddampingstructurecaneffectivelysuppressthevibration.

  • 标签: 约束阻尼层 瞬态响应 悬臂板 近似解 拉格朗日方程 约束阻尼结构
  • 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。

  • 标签: 弯曲 屈曲 矩形悬臂铁磁板 塑料屈服 弹性塑料磁发电机
  • 简介:Bygivingupanyassumptionsaboutdisplacementmodelsandstressdistribution,themixedstateHamiltonequationfortheaxisymmetricproblemofthethicklaminatedclosedcantilevercylindricalshellsisestablished.Anidenticalanalyticalsolutionisobtainedforthethin,moderatelythickandthicklaminatedclosedcantilevercylindricalshells.Allequationsofelasticitycanbesatis-fied,andallelasticconstantscanbetakenintoaccount.

  • 标签: Hamilton CANONICAL EQUATION state EQUATION CANTILEVER
  • 简介:Vibrationmodeoftheconstraineddampingcantileverisbuiltupaccordingtothemodesuperpositionoftheelasticcantileverbeam.ThecontrolequationoftheconstraineddampingcantileverbeamisthenderivedusingLagrange'sequation.Dynamicresponseoftheconstraineddampingcantileverbeamisobtainedaccordingtotheprincipleofvirtualwork,whentheconcentratedforceissuddenlyunloaded.Frequenciesandtransientresponseofaseriesofconstraineddampingcantileverbeamsarecalculatedandtested.Influenceofparametersofthedampinglayerontheresponsetimeisanalyzed.Analyitcalandexperimentalapproachesareusedforverification.Theresultsshowthatthemethodisreliable.

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  • 简介:Dynamicmodelingofacantileverbeamunderanaxialmovementofitsbasementispresent-ed.ThedynamicequationofmotionforthecantileverbeamisestablishedbyusingKane’sequationfirstandthensimplifiedthroughtheRayleigh-Ritzmethod.Comparedwiththeoldermodelingmethod,whichlineari-zesthegeneralizedinertiaforcesandthegeneralizedactiveforces,thepresentmodehngtakesthecoupledcubicnonlinearitiesofgeometricalandinertialtypesintoconsideration.Themethodofmultiplescalesisusedtodirectlysolvethenonlineardifferentialequationsandtoderivethenonlinearmodulationequationfortheprincipalparametricresonance.Theresultsshowthatthenonlinearinertiatermsproduceasofteningeffectandplayasignificantroleintheplanarresponseofthesecondmodeandthehigherones.Ontheotherhand,thenonlineargeometrictermsproduceahardeningeffectanddominatetheplanarresponseofthefirstmode.Thevalidityofthepresentmodelingisclarifiedthroughthecomparisonsofitscoefficientswiththoseexperimentallyverifiedinpreviousstudies.

  • 标签: CANTILEVER BEAM PARAMETRIC EXCITATION dynamic modeling
  • 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.

  • 标签: 弹塑性理论 弹性模量 金属材料 微观尺度 悬臂梁 应变梯度
  • 简介:StraightandBentnano-cantileverspecimensarerespectivelyproposedtoinvestigatethesingle-modeandmixed-modecrackinitiationattheCu/Siinterfaceedgeinnanoscalecomponents.Withaminuteloadingapparatus,allnanoscalesamplesareinsituloadedandobserved.Numericalanalysisisemployedtoacquirethecriticalinterfacialstressdistributionsduringcrackinitiation.ThestressconcentrationregionsneartheedgeofCu/Siinterfaceinallspecimensarewithinthescaleof100nm,andthecriticalnormalandshearstresseshaveacircularrelationinnanoscalecomponents,whichrepresentsthefracturecriterionoftheinterfaceinnanoscalecomponents.

  • 标签: NANOSCALE 伸臂 接口 裂缝开始 混合模式 薄电影
  • 简介:Thispaperdealswithfinitedeformationproblemsofcantileverbeamwithvariablesec-tionundertheactionofarbitrarytransverseloads.Bytheuseofamethodofvariablereplacement,thenonlineardifferentialequationwithvariedcoefficientfortheproblemcanbetransformedintoanequationwithvariableseparable.Theexactsolutioncanbeobtainedbytheintegrationmethod.Someexamplesaregiveninthepaper,andtheresultsoftheseexamplesshowthatthisexactsolutionincludestheexistingsolutionsinreferencesasspecialcases.

  • 标签: CANTILEVER beam with VARIABLE SECTION finite
  • 简介:这个工作学习在横梁的免费结束由非一致地分布式的连续负担和集中的负担组成的受到联合装载的苗条、非棱柱的伸臂横梁的大偏转。伸臂的材料被假定非线性地有弹性。在在张力、压缩的领域的应力和紧张之间的不同非线性的关系被考虑。数字答案的精确性被从以前的研究并且与一个实验室实验把他们与结果作比较评估。

  • 标签: 非均匀分布 悬臂梁 大挠度 自由端 非线性弹性 负载