简介：Theproblemonthedynamicresponseofarigidembeddedfoundationinthepresenceofanundergroundrigidtunnelandsubjectedtoexcitationofincidentanti-planeSHwavesisanalyzed.Byusingtheexactanalyticalsolutionforthetwo-dimensionalSH-wavepropagationinandaroundboththesurfacerigidfoundationandsubsurfacerigidtunnel,thoseaspectsoftheresultinggroundmotionsthatareofspecialinterestandimportanceforseismicresistantdesigninearthquakeanalyseshavebeenexamined.Thecomputedamplitudesoftheresultingperiodicgroundmotionsdisplayaverycomplicatedwave-interferencebetweenthesurfacefoundationandundergroundtunnelthatleadtoobservedstandingwavepatterns,togetherwithabruptchangesinthewaveamplitudesandlargeamplificationoftheincidentmotions.

简介：Forthedynamicsofarigidbodywithafixedpointbasedonthequaternionandthecorrespondinggeneralizedmomenta,adisplacement-basedsymplecticintegrationschemefordifferential-algebraicequationsisproposedandappliedtotheLagrange’sequa-tionsbasedondependentgeneralizedmomenta.Numericalexperimentsshowthatthealgorithmpossessessuchcharactersashighprecisionandpreservingsysteminvariants.Moreimportantly,thegeneralizedmomentabasedLagrange’sequationsshowuniquead-vantagesoverthetraditionalLagrange’sequationsinsymplecticintegrations.

简介：Accordingtothelower-boundtheoremoflimitanalysistheRigidFiniteElementMeth-od(RFEM)isappliedtostructurallimitanalysisandthelinearprogrammingsforlimitanalysisarededucedinthispaper.Moreover,theThermo-ParameterMethod(TPM)andParametricVariationalprinciples(PVP)areusedtoreducethecomputationaleffortwhilemaintainingtheaccuracyofsolutions.Abettersolutionisalsoobtainedinthispaper.

简介：地球作为triaxial被花僵硬身体，它在欧几里得的空格自由地旋转。开始的方程是Euler动态方程，与比比C的B和esmaller小的A。Euler方程被解决，并且数字结果被提供。在计算，下列参数被使用：(C~B)/A=0.00327353；(B-A)/C=0.00002196；(C-A)/e=0.00329549，并且地球的旋转的吝啬的尖速度，co=0.00007292115rad/s。计算证明除地球和它的旋转的免费Euler行列的自我旋转以外，那在那里存在免费点头：在theEarth的片刻的旋转轴和周期性地随着时间变化的吝啬的轴之间的点头角度，或角度。免费点头被调查。

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简介：Inthepresentpaper,afour-stageperforationmodelthataccuratelypredictstheresidualvelocityisdevelopedbyadoptinganenergymethod.Thefourstagesareplugformation,dishingformation,petalformationandprojectileexit.Inaddition,someimportantexperimentalresultsarepresentedandanalyzedtovalidatethepresentperforationmodel.Intheexperiments,highspeedcamerasystemisusedtorecordtheperforationprocess.Observationsontargetdamageandmeasurementsofinitialvelocitiesandresidualvelocitieswiththeaidofthesystemarepresented.Numericalsimulationsarecarriedoutforprojectilesagainstsingleandlayeredplatesadoptedintheexperiments.Theperforationprocessisstudiedandthedeformationandfailuremodesareobtained.Thepredictionsofnumericalsimulationsandanalyticalmodelarefoundinreasonablygoodagreementwiththoseofexperiments,andcanbeusedtopredicttheballisticlimitandresidualvelocityofstiffenedplatesperforatedbyrigidprojectiles.

简介：LetM(2)bethegroupofrigidmotionsoftheplane.TheFouriertransformandthePiancherelformulaonM(2)canbeexplicitlygivenbythegeneralgrouprepresentationtheory.Usingthisfact.weestablishakindofuncertaintyprincipleonM(2).Theresultcaneasilybegeneralizedtohigherdimensionalcases.AnapplicationoftheresultyieldsanuncertaintyprincipleontheEuclideanspacesobtainedbyR.S.Strichartz.

简介：RigidFiniteElementMethod(RFEM)wasproposedtosimulatethemechanicalbehaviorofdiscontinuousstructuressuchasrockandsoilstructures.Theauthors’workonthetheoryandapplicationsofRFEMissummarizedinthispaper.BasedonthetheoryofRFEM,theElasticBody-SeamsModel(EBSM)isproposedtotakethedeformationanddamageofrockmassesintoaccount.

简介：Basedonanincompressiblemodel,byusingthelargestaintheory,thecontactofarubberwedgewitharigidnotchisanalyzedbytheasymptoticmethod.Theproblemistreatedasasymmetriccase,andthecontactsurfaceissmooth.Thestressandstrainfieldneartheapexoftherubberwedgeisshowntobesingular,andtheangulardistributionsofstressandstrainareobtained.Twoimportantparameterstandtareintroducedtoattaintheconclusions.TheresultshowsthatthesingularexponentorderofstressfieldisInr.

简介：Themotionofaspark-inducedcavitationbubbleandanairbubbleneararigidboundaryisexperimentallystudiedbyusinghigh-speedphotography.Severaldimensionlessparametersareusedtodescribethegeometricalconfigurationofthebubble-bubble-boundaryinteraction.Thebubble-bubbleinteractioncanbeconsideredintwodifferentconditions.Thecavitationbubblewillcollapsetowardstheairbubbleiftheairbubbleisrelativelysmall,andawayfromtheairbubbleiftheairbubbleisrelativelylarge.Thetwozonesareidentifiedinthebubble-boundaryinteraction,andtheyarethedangerzoneandthesafetyzone.Therelativeposition,thebubble-boundarydistanceandthebubble-bubbledistanceplayimportantrolesinthebubble-bubble-boundaryinteraction,whichcanbeconsideredinseveralconditionsaccordingtotheresponsesofthebubbles.Airjetsarefoundtopenetrateintothecavitationbubbles.Thecavitationbubbleandtheairbubble(airjet)moveintheirownwaywithoutmixing.Themotionofacavitationbubblemaybeinfluencedbyanairbubbleand/orarigidboundary.Theinfluenceoftheairbubbleandtheinfluenceoftheboundarymaybecombined,likesomethingofavector.

简介：Asimplifiedfatigue-lifemodelisproposedforassessingtheseismicinelasticrotationalcapacityofsteelconnections.Firstrelationsaredevelopedforrigidsteelconnectionsunderlateralloading.Nextthisisextendedtoaccountfortheeffectsoftheweldedsteelmomentframe(WSMF)connectionsoftheso-calledpre-Northridgetype.Theseismicfatiguetheoryisvalidatedagainstexperimentalresults.Theexperimentswereconductedunderincreasingductilityamplitudcsuntiltheonsetoffracture.Miner'rulewasusedtoconvertthetestresultstogivenanequivalentconstantamplitudecyclicfatiguelife.Satisfactoryagreementisobtainedwhencomparingtheexperimentalobservationswiththetheoreticalpredictions.

简介：这份报纸为一组僵硬身体学习协调运动产生的问题。协调运动原语，相对equilibria和演习的二个班，当为产生的积木协调了运动，被给。在运动原语计划框架基于，一个控制方法面对不安为一个协调运动计划的柔韧的执行被建议。控制方法把相对equilibria稳定与演习设计相结合，并且导致计划框架的一个靠近环的运动。控制方法的表演通过数字模拟被说明了。

简介：Hamiltonianstructureofarigidbodyinacircularorbitisestablishedinthispaper.Withthereductiontechnique,theHamiltonianstructureofarigidbodyinacircularorbitisderivedfromLie-Poissonstructureofsemidirectproduct,andHamiltonianisderivedfromJacobi’sintegral.TheabovemethodcanbegeneralizedtoestablishtheHamiltonianstructureofarigidbodywithaflexibleattachmentinacircularor-bit.Atlast,anexampleofstabilityanalysisisgiven.

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简介：Anewmethodformeasuring3-Drigidbodydisplacementsisproposed,inwhichtwoperpendicularbeamsareemittedontotwosensitiveplanesofPSDsleingperpendiculartoeachother.Themethodcanbeusedtomeasure1-Dor2-Ddisplacementswhenrequired.Moreover,theexperimentalresultsarepresented,whichdemonstratethatthenewmethodhashighaccuracy,fastprocessingspeed,highreliability,andeasilybeingrealized.

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简介：Hausdorffdistancebetweentwocompactsets,definedasthemaximumdistancefromapointofonesettoanotherset,hasmanyapplicationincomputerscience.Itisagoodmeasureforthesimilarityoftwosets.ThispaperprovesthattheshapedistancebetweentwocompactsetsinR~ndefinedbyminimumHausdorffdistanceunderrigidmotionsisadistance.Theauthorsintroducesimilaritycomparisonproblemsinproteinscience,andproposethatthismeasuremayhavegoodapplicationtocomparisonofproteinstructureaswell.Forcalculationofthisdistance,theauthorsgiveonedimensionalformulasforproblems(2,n),(3,3),and(3,4).Theseformulascanreducetimeneededforsolvingtheseproblems.Theauthorsdidsomenumericalexperimentsfor(2,n).Onthesesetsofdata,thisformulacanreducetimeneededtoonefifteenthofthebestalgorithmsknownonaverage.Asnincreases,itwouldsavemoretime.

简介：Thisstudyinvestigatedtheinfluenceofvariousorganicallymodifiedmontmorillonites(organoclays)onthestructureandpropertiesofrigidpolyurethanefoam(RPUF)nanocomposites.Theorganoclaysweremodifiedwithcetyltrimethylammoniumbromide(CTAB),methyltallowbis(2-hydroxyethyl)quaternaryammoniumchloride(MT2ETOH)andtris(hydroxymethyl)aminomethane(THMA)anddenotedasCMMT,Cloisite30BandOMMT,respectively.MT2ETOHandTHMAcontainhydroxylgroups,whileTHMAdoesnothavelongaliphatictailinitsmolecule.X-raydiffractionandtransmissionelectronmicroscopyshowthatOMMTandCloisite30BcanbepartiallyexfoliatedintheRPUFnanocompositesbecausetheirintercalatingagentsMT2ETOHandTHMAcanreactwithisocyanate.However,CMMTmodifiedwithnonreactiveCTABismainlyintercalatedintheRPUFmatrices.Atarelativelylowfillercontent,theRPUF/CMMTcompositefoamhasahigherspecificcompressivestrength(theratioofcompressivestrengthagainsttheapparentdensityofthefoams),whileatrelativelyhighfillercontents,RPUF/Cloisite30BandRPUF/OMMTcompositeshavehigherspecificcompressivestrengths,highermodulusandmoreuniformporesizethantheRPUF/CMMTcomposite.

简介：Thispaperdevelopsgeometricnonlinearhybridformulationforflexiblemultibodysystemwithlargedeformationconsideringthermalefect.Diferentfromtheconventionalformulation,theheatfluxisthefunctionoftherotationalangleandtheelasticdeformation,therefore,thecouplingamongthetemperature,thelargeoverallmotionandtheelasticdeformationshouldbetakenintoaccount.Firstly,basedonnonlinearstrain–displacementrelationship,variationaldynamicequationsandheatconductionequationsforaflexiblebeamarederivedbyusingvirtualworkapproach,andthen,LagrangedynamicsequationsandheatconductionequationsofthefirstkindoftheflexiblemultibodysystemareobtainedbyleadingintothevectorsofLagrangemultiplierassociatedwithkinematicandtemperatureconstraintequations.Thisformulationisusedtosimulatethethermalincludedhub-beamsystem.Comparisonoftheresponsebetweenthecoupledsystemandtheuncoupledsystemhasrevealedthethermalchatteringphenomenon.Then,thekeyparametersforstability,includingthemomentofinertiaofthecentralbody,theincidentangle,thedampingratioandtheresponsetimeratio,areanalyzed.Thisformulationisalsousedtosimulateathree-linksystemappliedwithheatflux.Comparisonoftheresultsobtainedbytheproposedformulationwiththoseobtainedbytheapproximatenonlinearmodelandthelinearmodelshowsthesignificanceofconsideringallthenonlineartermsinthestrainincaseoflargedeformation.Atlast,applicabilityoftheapproximatenonlinearmodelandthelinearmodelareclarifiedindetail.