简介:Geoacoustic倒置为声学的域预言是重要的并且在浅水里匹配域本地化。梳火柴地倒置MFI和Reflectionloss倒置,多步为geoacoustic参数的贝叶斯的倒置被介绍。这个方法为随后的倒置作为优先的信息从一倒置使用了以后的概率密度PPD或倒置结果。首先,敏感参数被MFI决定。第二,感觉迟钝的参数被思考损失倒置基于PPD决定,倒置源于MFI。PPD结果比直接火柴地倒置,和一些参数的倒置结果显著地被改进的显示多步倒置方法更好被执行。为了在声音上表明多步倒置方法的优点,回答预言,传播损失的统计性质基于以后的概率被介绍。传播损失分发证明预言的声学的地基于多步倒置方法有更小的错误。
简介:这份报纸学习多相的thermoelasticcomposites的有效性质。把免费精力和吉布斯基于Helmholtz多相的composites的单个阶段,有效有弹性的张肌,热扩大的张肌,和特定的热的免费精力借助于体积一般水准被导出这些阶段免费精力。特别强调以经常紧张、经常压力的状况,修改Eshelby的micromechanics理论在被开发被放在有效的特定的热的新分析表情的推导上,在包括之间的相互作用被考虑。作为一个解说性的例子,为三阶段的thermoelastic的有效的特定的热的分析表示合成被介绍。
简介:Theobjectiveofthisinvestigationistoexaminethecorrectnessandefficiencyofthechoiceofboundaryconditionswhenusingassumedmodeapproachtosimulateflexiblemulti-bodysystems.ThedisplacementfieldduetodeformationisapproximatedbytheRayleigh-Ritzassumedmodesinfloatingframeofreference(FFR)formulation.Thedeformationsobtainedbytheabsolutenodalcoordinate(ANC)formulationwhicharetransformedbytwosetsofreferencecoordinatesareintroducedasacriteriontoverifytheaccuracyofthesimulationresultsbyusingtheFFRformulation.Therelationshipbetweenthedeformationsobtainedfromdifferentboundaryconditionsisrevealed.Numericalsimulationexamplesdemonstratethattheassumedmodeswithcantilevered-free,simply-supportedandfreefreeboundaryconditionswithoutinclusionofrigidbodymodesaresuitableforsimulationofflexiblemulti-bodysystemwithlargeoverallmotion,andthesamephysicaldeformationcanbeobtainedusingthosemodefunctions,differonlybyacoordinatetransformation.Itisalsoshownthatwhenusingmodeshapeswithstaticallyindeterminateboundaryconditions,significanterrormayoccur.Furthermore,theslidercrankmechanismwithrigidcrankisaccurateenoughforinvestigatingboundaryconditionproblemofflexiblemulti-bodysystem,whichcostsignificantlesssimulatingtime.
简介:Inthispaper,weestablisharesultofLeray-Schauderdegreeontheorderintervalwhichisinducedbyapairofstrictloweranduppersolutionsforasystemofsecond-orderordinarydifferentialequations.Asapplications,weprovetheglobalexistenceofpositivesolutionsforamulti-parametersystemofsecond-orderordinarydifferentialequationswithrespecttoparameters.ThediscussionisbasedontheresultofLeraySchauderdegreeontheorderintervalandthefixedpointindextheoryincones.
简介:有多域和三倍的连接点的椭圆形的接口问题在工程和科学有宽应用程序。然而,角落奇特为大多数存在方法使它成为一个挑战性的问题。一个精确、有效的方法被需要。在这份报纸,有non-body-fitting格子的一个有效非传统的有限元素方法被建议与多域和三倍的连接解决椭圆形的接口问题。结果方程的线性系统是积极的明确如果为在领域的椭圆形的方程的矩阵系数是积极的明确。数字实验证明这个方法是在为piecewise的L标准精确的大约第二份订单光滑的答案。角落奇特能以一个方法被处理以便精确性不堕落。三倍的连接小心地被解决,它不需要被放在格子上,给我们的方法潜力对待没有改革网孔的动人的接口问题。
简介:ThispaperstudiesMulti-modescontrolmethodforlibrationpointsformationestablishmentandreconfiguration.Firstly,relationsbetweenoptimalimpulsecontrolandFloquetmodesareinvestigated.Methodofgeneratingmodesisproposed.Characteristicsofthemodecoefficientsstimulatedatdifferenttimearealsogiven.Studiesshowthatcoefficientsofcontrolledmodescanbeclassifiedintofourtypes,andformationestablishmentandreconfigurationcanbeachievedbymulti-impulsecontrolwiththepresentedmethodofgeneratingmodes.Then,sincelibrationpointsformationisgenerallyunstable,mutli-modeskeepingcontrolmethodwhichcanstabilizefiveFloquetmodessimultaneouslyisproposed.Finally,simulationonformationestablishmentandreconfigurationarecarriedoutbyusingmethodofgeneratingmodesandmutli-modeskeepingcontrolmethod.Resultsshowthattheproposedcontrolmethodiseffectiveandpractical.
简介:Thedynamicsformulti-linkspatialflexiblemanipulatorarmsisinvestigated.ThesystemconsideredhereisanN-flexible-linkmanipulatordrivenbyNDC-motorsthroughNrevoluteflexiblejoints.Theflexibilityofeachflexiblejointismodeledasalinearlyelastictorsionalspring,andthemassofthejointisalsoconsidered.Fortheflexibilityofthelink,allofthestretchingdeformation,bendingdeformationandthetorsionaldeformationareincluded.ThecompletegoverningequationsofmotionofthesystemarederivedviatheLagrangeequations.Thenonlineardescriptionofthedeformationfieldoftheflexiblelinkisadoptedinthedynamicmodeling,andthusthedynamicstiffeningeffectsarecaptured.Basedonthismodel,ageneral-purposesoftwarepackagefordynamicsimulationofmulti-linkspatialflexiblemanipulatorarmsisdeveloped.Severalillustrativeexamplesaregiventovalidatethealgorithmpresentedinthispaperandtoindicatethatnotonlydynamicstiffeningeffectsbutalsotheflexibilityofthestructurehassignificantinfluenceonthedynamicperformanceofthemanipulator.
简介:在现在的纸,包含三个任意的函数为的一个一般解决方案概括(2+1)维的KdV-mKdV方程,它被导出从概括(1+1)维的KdV-mKdV方程,首先借助于Wiess被介绍,小鼓,Carnevale(WTC)截断方法。然后有考虑的几条能量守恒定律的multisymplectic明确的表达被介绍为概括(2+1)维的KdV-mKdV方程基于桥的multisymplectic理论。随后,源于以便以Jacobi椭圆形的功能的合理功能模仿周期的波浪答案一般答案,一个半含蓄的multi-symplectic计划被构造那等价于Preissmann计划。从数字实验的结果,我们能断定multi-symplectic计划能精确地模仿周期的波浪答案概括(2+1)维的KdV-mKdV方程当时近似保存能量守恒定律。
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.