简介：基于颤动的精力harvester是实质上在一个有限频率范围工作的一个共鸣器。增加工作频率范围是一个挑战性的问题。这份报纸为提高经由内部回声收获的精力揭示新奇可能性。内部回声精力harvester被建议。刺激连续地作为Gaussian白噪音，一个秒顺序过滤器定义的有颜色的噪音，狭窄乐队的噪音，和指数地相关的噪音被假定。相应平均root-mean-square产量电压被计算。数字结果证明内部回声增加操作带宽和产量电压。

简介：Ananalyticalstudyofthetwodegreesoffreedomnonlineardynamicalsystemispresented.Theinternalmotionofthesystemisseparatedanddescribedbyonefourthorderdifferentialequation.AnapproximateapproachallowsreducingtheproblemtotheDuffingequationwithadequateinitialconditions.Anovelideaforaneffectivestudyofnonlineardynamicalsystemsconsistinginaconceptofthesocalledlimitingphasetrajectoriesisapplied.Bothqualitativeandquantitativecomplexanalyseshavebeenperformed.Importantnonlineardynamicaltransitiontypephenomenaaredetectedanddiscussed.Inparticular,nonsteadyforcedsystemvibrationsareinvestigatedanalytically.

简介：Thesystemofawedgedisclinationdipoleinteractingwithaninternalcrackwasinvestigated.Byusingthecomplexvariablemethod,theclosedformsolutionsofcomplexpotentialstothisproblemwerepresented.Theanalyticformulaeofthephysicsvariables,suchasstressintensityfactorsatthetipsofthecrackproducedbythewedgedisclinationdipoleandtheimageforceactingondisclinationdipolecenterwereobtained.Theinfluenceoftheorientation,thedipolearmandthelocationofthedisclinationdipoleonthestressintensityfactorswasdiscussedindetail.Furthermore,theequilibriumpositionofthewedgedisclinationdipolewasalsoexamined.Itisshownthattheshieldingorantishieldingeffectofthewedgedisclinationtothestressintensityfactorsissignificantwhenthedisclinationdipolemovestothecracktips.

简介：Basedonanewdefinitionofnonlocalvariable,thispaperestablishestheLagrangianformulationforcontinuumwithinternallong-rangeinteractions.Distinguishedfromtheexistingtheories,thenonlocaltermintheLagrangianformulationautomaticallysatisfiesthezeromeanconditiondeterminedbytheactionandreactionlaw.Bythisformulation,elasticwaveinarodwiththeinternallong-rangeinteractionsisinvestigated.Thedispersionoftheelasticwaveispredicted.

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简介：Stabilityanddynamiccharacteristicsofaballbearing-rotorsystemareinvestigatedundertheeffectoftheclearanceintheballbearing.DifferentclearancevaluesareassumedtocalculatethenonlinearstabilityofperiodicsolutionwiththeaidoftheFloquettheory.Bifurcationandchaosbehaviorareanalyzedwithvariationoftheclearanceandrotationalspeed.Itisfoundthattherearethreeroutestounstableperiodicsolution.Theperiod-doublingbifurcationandthesecondaryHopfbifurcationaretwousualroutestoinstability.Thethirdrouteistheboundarycrisis,achaoticattractoroccurssuddenlyasthespeedpassesthroughitscriticalvalue.Atlast,theinstablerangesfordifferentinternalclearancevaluesaredescribed.Itisusefultoinvestigatethestabilitypropertyofballbearingrotorsystem.

简介：Theharmonysearchalgorithmisappliedtooptimumdesignsofafunctionallygraded(FG)-carbonnanotubes(CNTs)-reinforcedpipesconveyingfluidsubjectedtomovingload.ThestructureismodelledbyReddycylindricalshelltheoryandthefinalequationsareobtainedbyprincipalofHamilton.Basedondifferentialquadraturemethod(DQM),thedynamicdisplacementofsystemisderived.

简介：Theprincipleand1:3internalresonanceofarectangularthinplateinatransversemagneticfieldisinvestigated.Basedonthemagneto-elasticvibrationequationandelectromagneticforceexpressionsofthethinplates,thenonlinearmagneto-elasticvibrationdifferentialequationsofrectangularplatesunderexternalexcitationinatransversemagneticfieldarederived.Forarectangularplatewithonesidefixedandthreeothersidessimplysupported,thetwo-degree-offreedomnonlinearDuffingvibrationdifferen-tialequationsareproposedbythemethodofGalerkin.Themethodofmultiplescalesisadoptedtosolvethemodelequationsandobtainfourfirst-orderordinarydifferentialequationsgoverningmodulationoftheamplitudesandphaseanglesinvolvedviathefirst-orderorthesecond-orderprimary-internalreso-nances.Withanumericalexample,theamplitudefrequencyresponsecurves,timehistoryresponses,phaseportraitsandPoincaremapsofthefirsttwoordervibrationmodesviaprinciple-internalresonancearerespectivelycaptured.Andtheeffectsofexternalexcitationamplitudes,magneticfieldintensitiesandthicknessesonthevibrationofsystemarediscussed.Theresultsshowthattheresponseisdominatedbythelowmodewhenprinciple-internalresonanceoccurs.Theinternalresonanceprovidesamechanismfortransferringenergyfromahighmodetoalowmode.

简介：Theelectromechanicalphasetransitionforadielectricelastomer(DE)tubehasbeendemonstratedinrecentexperiments,whereitisfoundthattheunbulgedphasegraduallychangedintobulgedphase.Previoustheoreticalworksonlystudiedthetransitionprocessunderpressurecontrolcondition,whichisnotconsistentwiththerealexperimentalcondition.Thispaperfocusesonmorecomplexfeaturesoftheelectromechanicalphasetransitionunderinternalpressureofconstantmass.WederivetheequilibriumequationsandtheconditionforcoexistentstatesforaDEtubeunderaninternalpressure,avoltagethroughthethicknessandanaxialforce.Wefindthatundermasscontrolconditionthevoltageneededtomaintainthephasetransitionincreasesastheprocessproceeds.Weanalyzetheentireprocessofelectromechanicalphasetransitionandfindthattheevolutionofconfigurationsisalsodifferentfromthatforpressurecontrolcondition.

简介：Thispaperaddsanegativevelocityfeedbacktothedynamicalsystemoftwin-tailaircrafttosuppressthevibration.Thesystemisrepresentedbytwocoupledsecond-ordernonlineardifferentialequationshavingbothquadraticandcubicnonlinearities.Thesystemdescribesthevibrationofanaircrafttailsubjectedtobothmulti-harmonicandmulti-tunedexcitations.Themethodofmultipletimescaleperturbationisadoptedtosolvethenonlineardifferentialequationsandobtainapproximatesolutionsuptoth...

简介：Thebasicequationsoffreecapillary-gravitysurface-wavesinacircularcylindricalbasinwerederivedfromLuke'sprinciple.TakingGalerkin'sexpansionofthevelocitypotentialandthefreesurfaceelevation,thesecond-orderperturbationequationswerederivedbyuseofexpansionofmultiplescale.Thenonlinearinteractionswiththesecondorderinternalresonanceofthreefreesurface-waveswerediscussedbasedontheabove.Theresultsinclude:derivationofthecoupleequationsofresonantinteractionsamongthreewavesandtheconservationlaws;analysisofthepositionsofequilibriumpointsinphaseplane;studyoftheresonantparametersandthenon-resonantparametersrespectivelyinallkindsofcircumstances;derivationofthestationarysolutionsofthesecond-orderinteractionequationscorrespondingtodifferentparametersandanalysisofthestabilitypropertyofthesolutions;discussionoftheeffectivesolutionsonlyinthelimitedtimerange.Theanalysismakesitclearthattheenergytransformationmodeamongthreewavesdiffersbecauseofthedifferentinitialconditionsundernontrivialcircumstance.Theenergymayeitherexchangeamongthreewavesperiodicallyordamporincreaseinsinglewaves.

简介：Thenonlinearnormalmodes(NNMs)associatedwithintegrnalresonancecanbeclassifiedintotwokinds:uncoupledandcoupled.ThebifurcationproblemofthecoupledNNMofsystemswith1:2:5dualinternalresonanceisintwovariables.ThesingularanalysisofitispresentedafterseparatingthetwovariablesbytakingadvantageofMaplealgebra,andsomenewbifurcationpatternsarefound.DifferentfromtheNNMsofsystemswithsingleinternalresonance,thenumberoftheNNMsofsystemswithdualinternalresonancemaybemoreorlessthanthenumberofthedegreesoffreedom.Atlast,itispointedoutthatbifurcationproblemsintwovariablescanbeconvenientlysolvedbyseparatingvariablesaswellasusingcouplingequations.

简介：Globalbifurcationsandmulti-pulsechaoticdynamicsforasimplysupportedrectangularthinplatearestudiedbytheextendedMelnikovmethod.Therectangularthinplateissubjecttotransversalandin-planeexcitation.Atwo-degree-of-freedomnonlinearnonautonomoussystemgoverningequationsofmotionfortherectangularthinplateisderivedbythevonKarmantypeequationandtheGalerkinapproach.Aone-tooneinternalresonanceisconsidered.Anaveragedequationisobtainedwithamulti-scalemethod.Aftertransformingtheaveragedequationintoastandardform,theextendedMelnikovmethodisusedtoshowtheexistenceofmulti-pulsechaoticdynamics,whichcanbeusedtoexplainthemechanismofmodalinteractionsofthinplates.AmethodforcalculatingtheMelnikovfunctionisgivenwithoutanexplicitanalyticalexpressionofhomoclinicorbits.Furthermore,restrictionsonthedamping,excitation,anddetuningparametersareobtained,underwhichthemulti-pulsechaoticdynamicsisexpected.Theresultsofnumericalsimulationsarealsogiventoindicatetheexistenceofsmallamplitudemulti-pulsechaoticresponsesfortherectangularthinplate.

简介：电影动量和在加速上的薄有限幂定律液体的热运输特征上的内部加热来源的效果不稳定的水平拉长的接口被学习。不同于这块地里的很古典的工作，为改变热电导率的液体电影和概括Fouriers法律的一般表面温度分布被考虑。适当类似转变被用来与一组二点的平常的微分方程(颂诗)把强烈非线性的管理部分微分方程(PDE)变换成一个边界价值问题。在液体电影厚度和摇摆参数之间的通讯在MATLAB用BVP4C节目被导出。自我类似颂诗的数字答案用与一个Runge-Kutta重复程序和牛顿计划相结合的射击技术被获得。液体上的深奥物理参数的效果水平速度和温度分发被介绍并且讨论。