简介：Thelargedesignfreedomofvariable-stiffness(VS)compositematerialpresupposesitspotentialforwideengineeringapplication.PreviousresearchindicatesthatthedesignofVScylindricalstructureshelpstoincreasethebucklingloadascomparedtoquasi-isotropic(QI)cylindricalstructures.Thispaperfocusesontheanti-bucklingperformanceofVScylindricalstructuresundercombinedloadsandtheefficientoptimizationdesignmethod.Twokindsofconditions,bendingmomentandinternalpressure,andbendingmomentandtorqueareconsidered.Influencesofthegeometricaldefects,ovality,onthecylinder'sperformancesarealsoinvestigated.Toincreasethecomputationalefficiency,anadaptiveKrigingmeta-modelisproposedtoapproximatethestructuralresponseofthecylinders.InthisimprovedKrigingmodel,amixedupdatingruleisusedinconstructingthemeta-model.Ageneticalgorithm(GA)isimplementedintheoptimizationdesign.TheoptimalresultsshowthatthebucklingloadofVScylindersinallcasesisgreatlyincreasedascomparedwithaQIcylinder.

简介：在这篇论文，半活跃可变僵硬(SVS)设备习惯于电报的参量的颤动的运动的参量的刺激，和方程与这台SVS设备引起的减少电报摆动被介绍。开／关控制算法被用来操作SVS控制设备。有SVS设备的电缆线的颤动反应数字地在频率和时间域并且为参量、古典的回声颤动条件为许多另外的僵硬联合被学习。数字研究进一步考虑电报下垂效果。从数字结果，SVSdevice有效地压制电报回声颤动反应，这被显示出，并且当设备的僵硬增加，设备完成颤动的更大的抑制。而且，SVS设备在电报下面增加刺激的批评轴的排水量，这被显示出参量的颤动条件。

简介：一台创新可变僵硬设备基于数字模拟被建议并且调查。设备，叫了一个合拢的可变僵硬弹簧(FVSS)，能广泛地被使用，特别在有适应僵硬的调节集体dampers(TMD)。FVSS的一个重要特征是它的能力通过在它的支持之间的距离的一个小面值硬币改变在更低、上面的界限之间的僵硬。这个特殊特征在更短的时间间隔导致更低的时间落后错误和重新调整。设备的管理方程与类似的元素为对称的FVSS被导出并且简化。这台设备然后被用来控制single-degree-of-freedom(SDOF)象multi-degree-of-freedom(MDOF)一样的结构经由半活跃的TMD的结构。数字模拟被进行为这些结构比较几个控制案例。使它更现实主义，有它的自己的限制的一台真实直接当前的马达没有限制除了一个理想的控制案例被模仿，两个都，结果被比较。建议设备能有效地被用来压制结构的不受欢迎的颤动并且更加与一台被动设备相比改进控制器的表演，这被显示出。

简介：

简介：Inthisletter,acomparisonbetweenthreetypes(twolinearandonenonlinear)ofmodelsofskeletalmusclestiffnessisshown.ResultsarecomparedwithexperimentaldataforbicepsbrachiiinthecaseofmusclestretchingandwiththeHillequationforabiologicalmuscle.Itisshownthatresultsfornonlinearstiffnessmodelincaseoflength-forcerelationshipfitstotheexperimentaldata.

简介：Inthispaper,twoirreversibleexothermicautocatalyticreactionswhichcarryoutincontinuousstirredtankreactor（CSTR）areconsidered.Adifferential-algebraicsystemisappliedtomodelthesechemicalreactions.Thestabilityandthedynamicbehaviorarestudiedforthedifferential-algebraicsystem.TheHopfbifurcationappearswhentheparameterexceedsacriticalvalue.Inordertoeliminatethiscomplexbehavior,thedifferential-algebraicsystemisdescribedbyasingle-inputandsingle-outputsystemwithparametervaryingwithindefiniteintervals,andthenvariablestructurecontrolwithslidingmodebasedonaspecialpowerreachinglawisdesignedtostabilizethischemicalsystem.Numericalsimulationsaregiventoillustratetheeffectivenessofthemethod.

简介：

简介：为了与僵硬学习负担转移机制和混合堆积的适用的能力，核心(MPSC)被插入预制增强的具体堆积(PRCP)形成，在原处测试与不同长度，直径，水水泥比率和PRCP包含MPSC，水泥混合了堆积，并且钻洞堆积，被执行。限制适用的能力，负担解决曲线和MPSC的压力分发，混合堆积被获得。在水泥土壤和PRCP之间的负担转移被有限元素方法分析(女性)。测试结果和女性的分析证明MPSC充分从从外部顶装进转移内部水泥的PRCP的混合堆积和高压缩强度玷污的水泥利用了大磨擦，并且那插入进混合堆积的PRCP改变混合堆积的压力分发并且改进在混合堆积和土壤之间的摩擦抵抗。长度和MPSC的节区域onPRCP两个都有最佳价值。采用MPSC在改进软土壤地面的适用的能力是有效的。

简介：磨擦，一枚戒指有弹性地支持了的一个磁盘的阶段特征被调查并且过去常解释僵硬增加现象的机制。只要磨擦被维持，磁盘上的磁盘和旋转的团之间的平均阶段差别毫无疑问是不到蟺/2。当磨擦完成时，阶段差别快速来临到蟺。这行为独立于磨擦系统的物理参数。理论结果是与实验验证的品质上。关键词僵硬增加现象-阶段特征-磨擦转子这个工程被支持由在里面英国的皇家学会和中国(10672006)的国家自然科学基础的来交情。

简介：Apreconditioningmethodforthefiniteelementstiffnessmatrixisgiveninthispaper.Thetriangulationisrefinedinasubregion;thepreconditioningprocessiscomposedofresolutionoftworegularsubproblems;theconditionnumberofthepreconditionedmatrixisO(1+logH/h),whereHandharemeshsizesoftheunrefinedandlocalrefinedtriangulationsrespectively.

简介：Contact-impactprocessesoccuratmostcasesinmultibodysystems.Sub-periodsandsub-regionalmethodsarefrequentlyusedrecently,anddifferentcoordinatesareintroducedinbothoftheapproaches.However,thesub-regionalmethodseemstobemoreeffective.Floatingframeofreferenceformulationiswidelyusedforcontacttreatment,whichdescribesdisplacementsbytherigidbodymotionandasmallsuperposeddeformation,andthecoordinatesdepictingthedeformationincludefiniteelementnodalcoordinatesandmodalcoordinates,theformerdealswiththecontact/impactregion,andthelaterdescribesthenon-contactregion.Inthispaper,freeinterfacesubstructuremethodisusedinmodeling,andthedynamicequationofasinglebodyisderived.Then,usingtheLagrangeequationofthefirstkind,thedynamicequationsofmultibodysystemsareestablished.Furthermore,contact-impactareasaretreatedthroughadditionalconstraintequationsandLagrangemultipliers.Usingsuchapproach,thenumberofsystemcoordinatesandthedimensionsofmassmatrixaresignificantlyreducedwiththemodaltruncation,thereforebothoftheefficiencyandaccuracyareguaranteed.Finiteelementmethodinthelocalcontactregioncandealwithcontact/impactbetweenarbitrarilycomplexinterfaces,whereas,additionalcontactconstraintsusedinthenodaldescriptionregioncanavoidthecustomizedparametersthatareusedinthecontinuousforcemodel.

简介：Large-scalewindturbinegeneratorsystemshavestrongnonlinearmultivariablecharacteristicswithmanyuncertainfactorsanddisturbances.Automaticcontroliscrucialfortheefficiencyandreliabilityofwindturbines.Onthebasisofsimplifiedandpropermodelofvariablespeedvariablepitchwindturbines,theeffectivewindspeedisestimatedusingextendedKalmanfilter.Intelligentcontrolschemesproposedinthepaperincludetwoloopswhichoperateinsynchronismwitheachother.Atbelow-ratedwindspeed,theinnerloopadoptsadaptivefuzzycontrolbasedonvariableuniverseforgeneratortorqueregulationtorealizemaximumwindenergycapture.Atabove-ratedwindspeed,acontrollerbasedonleastsquaresupportvectormachineisproposedtoadjustpitchangleandkeepratedoutputpower.Thesimulationshowstheeffectivenessoftheintelligentcontrol.

简介：绳的一个分离模型被开发并且过去常模仿在一端修理的绳的飞机运动。实际上，二个系统被介绍，其成员是僵硬却非理想的关节包含弹性或驱散。驱散被粘滞的抑制简单地反映当模特儿，而弯曲僵硬概念为横梁和简单几何公式基于古典弯曲弯曲的时刻关系。运动的方程被导出，他们的复杂性从计算观点被讨论。自从修改扩大向后的区别，现金的公式(MEBDF)被实现解决结果起始的价值问题，技术计划被构画出。数字实验弹性被执行并且影响并且在模型的行为上抑制被分析。基本精力原则被用来验证获得的结果。

简介：加框的的结构通常是有石工技术墙的infilled。他们可以在僵硬和力量引起重要增加，减少变丑需求并且增加系统的精力驱散能力。在另一方面，石工技术面板的不规则的安排可以在一些区域导致损坏的集中，与否定效果；例如软的故事机制并且砍在短列的失败。因此，填入墙的存在不应该被忽视，特别在中等、高的seismicity的区域。到这个目的，简单模型为稳固的填入墙是可得到的，例如斜没有紧张神气模型，当有洞的infilled框架足够地没被调查时。在这研究，infilled框架的力量和僵硬上的洞的效果借助于大约150试验性、数字的测试被调查。包含的主要参数被识别，在填入考虑洞的一个简单模型被开发并且由不同研究人员与另外的模型相比求婚了。模型，基于力量和僵硬减小因素的使用，考虑在洞附近增强元素的开的尺寸和存在。建议减小因素的一个应用程序的一个例子也被举。

简介：Thedynamicdeformationofharmonicvibrationisusedastheshapefunctionsofthefiniteannularplateelement.andsomeintegrationdifficultiesrelatedtotheBessel’sfunctionsaresolvedinthispaper.Thenthedynamicstiffnessmatrixofthefiniteannularplateelementisestablishedinclosedformandcheckedbythedirectstiffnessmethod.Thepaperhasgivenwideconveragefordecomposingthedynamicmatrixintothepowerseriesoffrequencysquare.Byutilizingtheaxialsymmetryofannular,themodeswithdifferentnumbersofnodaldiametersareseparatelytreatedThussometerseandcompleteresultsareobtainedasthe.foundationofstructuralcharacteristicanalysisanddynamicresponsecomputation.

简介：Thestiffnessandstrengthofextracellular(EC)regionofcadherinareproposedtobetwoimportantmechanicalpropertiesbothforcadherinasamechanotransductorandfortheformationofcell-celladhesion.Inthisstudy,wequantitativelycharacterizedthestiffnessandstrengthofECstructurewhenitbindswithdifferenttypesofionsbymoleculardynamicssimulations.ResultsshowthatECstructureexhibitsarod-likeshapewithhighstiffnessandstrengthwhenitbindswiththebivalentionsofcalciumormagnesium.However,itswitchestoasoftandcollapsedconformationwhenitbindswiththemonovalentionsofsodiumorpotassium.ThisstudyshedslightontheimportantroleofthebivalentionsofcalciuminthephysiologicalfunctionofEC.

简介：

简介：动态僵硬矩阵方法被使用在这篇论文计算壳girder的颤动。这个方法不能仅仅简化计算模型，而且精确地得到高得多的频率和回答。为横向的颤动的一根Timoshenko横梁的动态僵硬矩阵的分析表情在这篇论文被介绍。旋转惯性的所有效果并且砍变丑在明确的表达被考虑。结果与Wittrick威廉算法相结合的动态僵硬矩阵被用来计算自然频率和299,500DWTVLCC的模式形状，然后震动的回答被模式重叠方法解决。计算结果与从另外的近似方法和实验获得的那些相比，并且它显示方法精确、有效。

简介：Theuseofoscillatingflexiblefinsinpropulsionhasbeenthesubjectofseveralstudiesinrecentyears,butattentionisrarelypaidtothespecificroleofstiffnessprofileinthrustproduction.Stiffnessprofileisdefinedasthevariationinlocalchordwisebendingstiffness(EI)ofafin,fromleadingtotrailingedge.Inthisstudy,flexiblefinswithastandardNACA0012shapeweretestedalongsidefinswithastiffnessprofilemimickingthatofaPumpkinseedSunfish(Lepomisgibbosus).Thefinswereoscillatedwithapitchingsinusoidalmotionoverarangeoffrequenciesandamplitudes,whiletorque,lateralforceandstaticthrustweremeasured.Overtherangeofoscillationparameterstested,itwasshownthatthefinwithabiomimeticstiffnessprofileofferedasignificantimprovementinstaticthrust,comparedtoafinofsimilardimensionswithastandardNACA0012aerofoilprofile.Thebiomimeticfinalsoproducedthrustmoreconsistentlyovereachoscillationcycle.Acomparisonoffinmaterialsofdifferentstiffnessshowedthattheimprovementwasduetothestiffnessprofileitself,andwasnotsimplyaneffectofalteringtheoverallstiffnessofthefin.Finsofthesamestiffnessprofilewereobservedtofollowthesamethrust-powercurve,independentofthestiffnessofthemouldingmaterial.Biomimeticfinswereshowntoproduceupto26%greaterthrustperwattofinputpower,withintheexperimentalrange.

简介：Westudythebucklingofaonefibercompositewhosematrixstifnessisslightlydependentonthecompressiveforce.Weshowthattheequilibriumcurvesofthesystemexhibitalimitloadwhentheinducedstifnessparametergetsbiggerthanathreshold.Thislimitloadincreaseswhenthestifnessparameterisincreasinganditisrelatedtoapossiblelocalizedpathinthepost-bucklingdomain.Suchachangeinthemaximumloadmaybeverydesirablefromastructuralstandpoint.