简介：AftertheprogressivecollapseofRonanPointapartmentinUKin1968,intensiveresearchefforthadbeenspentondevelopingguidelinesfordesignofneworstrengtheningtheexistingstructurestopreventprogressivecollapse.However,onlyveryfewbuildingdesigncodesprovidesomerathergeneralguidance,nodetaileddesignrequirementisgiven.ProgressivecollapseoftheAlfredP.MurrahFederalbuildinginOklahomaCityandtheWorldTradeCentre(WTC)sparkedagaintremendousresearchinterestonprogressivecollapseofstructures.Recently,USDepartmentofDefence(DoD)andUSGeneralServiceAdministration(GSA)issuedguidelinesforstructureprogressivecollapseanalysis.Thesetwoguidelinesaremostcommonlyused,buttheiraccuracyisnotknown.Thispaperpresentsnumericalanalysisofprogressivecollapseofanexampleframestructuretoblastloads.TheDoDandGSAproceduresarealsousedtoanalysethesameexamplestructure.Numericalresultsarecomparedanddiscussed.Theaccuracyandtheapplicabilityofthetwodesignguidelinesareevaluated.

简介：Inthisarticle,theauthorsconsiderthecollapsesolutionsofCauchyproblemforthenonlinearSchrdingerequationiψt+1/2△ψ-1/2ω2|x|2ψ+|ψ|2ψ=0,x∈R2,whichmodelstheBose-Einsteincondensatewithattractiveinteractions.Theauthorsestablishthelowerboundofcollapserateast→T.Furthermore,theL2-concentrationpropertyoftheradiallysymmetriccollapsesolutionsisobtained.

简介：

简介：在一座岩石山岳的地下的洞的倒塌的组成的法律基于实验室的结果被调查并且用分析、数字的模型回答实验，和计算。这被显示出地下的开始在上的失败的主要机制为1～10m/s的实践山峰粒子速度振幅范围重要由于关键块的秋天是房顶和墙破裂。在这个负担范围上，压碎的材料具有更加少些重要性。断绝的几何学主要影响关键块的稳定性。进一步的探穴微弱地取决于近隧道的地区的块结构。秋天材料的吝啬的体积是为不同结构的岩石山岳的相当稳定的数量。在高断裂的地区的更低的隧道稳定性被不稳定的关键块的存在和围住块折断的力量特征的减少的更高的可能性引起。平均的块尺寸的减少是一个不太重要的伴随因素。

简介：ZhongyuanoilfieldsaremainlylocatedinDongpudepression,wherethegeologicalconditionswereextremelycomplicatedandtheexternalstressisabnormallyhigh,thepipeusedmayfailintheradialdirectionowingtowellshrinkagecausedbythecreepofsaltrock,leadingcatastrophiceconomicloss.Thereforethisregionhasbeenwellkownasatouchstoneforhighcollapseresistancecasingsincelongbefore.Inordertosatisfytherequirementforhigh-collapsestrengthcasingowingtothecreepofsaltbedstratuminDongpuDepressionregion,BG140TT,BG150TTandBG160TThigh-strengthcollapseresistancecasingseriesweredevelopedtobettercopewiththeseveregeologicalconditions.Amongthecasingseries,aBG160TTnon-APIspecificationcasingwithcollapsestrengthnotlessthan170MPawereprepared.Uptopresent,allthesehigh-strengthcollapseresistancecasinghavebeensuccessfullyappliedintheDongpuDepressionregion.Theresearchconcept,mechanicalproperties,aswellasapplicationresultwereintroducedinthispaper.

简介：Inthispaper,weconsiderthefollowingchemotaxismodelwithratio-dependentlogisticreactiontermu/t=D▽(▽u-u▽ω/ω)+u(α-bu/ω),(x,t)∈QT,ω/t=βu-δω,(x,t)∈QT,u▽㏑(u/w)·=0,x∈Ω,00,x∈,w(x,0)=w0(x)>0,x∈,Itisshownthatthesolutiontotheproblemexistsgloballyifb+β≥0andwillblowuporquenchifb+β<0bymeansoffunctiontransformationandcomparisonmethod.Variousasymptoticbehaviorrelatedtodifferentcoefficientsandinitialdataisalsodiscussed.

简介：在强风和影响负担下面造结构的进步倒塌在整个世界吸引了大注意。进步倒塌分析为对进步倒塌造结构爆炸并且影响负担的一个经济、安全的图案是必要的。因为进步倒塌的灾难的性质和构造或翻新大楼抵抗它的潜在地高的费用，进步倒塌分析方法是可靠的，是必要的。为工程师，他们执行进步倒塌评估的方法论不必仅仅精确、简明，而且容易快被使用并且工作。因此，许多研究人员一直在花大量在最近开发可靠、有效、直接的进步倒塌分析方法的努力。在现在的纸，在文学可得到的当前的进步倒塌分析方法被考察。他们的适用性，适用性和可靠性被讨论。我们为在强风负担下面的增强的具体框架的进步倒塌分析的最近的建议新方法也被介绍。

简介：这研究由于地震刺激在结构的倒塌的上下文为大、复杂的结构的系统的混合模拟检验集成方法的表演。目标申请未必为即时测试，但是相当为包含大规模物理基础的模型和高度非线性的数字模型。四案例研究被介绍并且讨论。在第一案例研究，也就是，包括二个广泛地使用的方法的集成计划的精确性与重复的改正数字修改了含蓄的Newmark的版本(反复)并且切开操作员(非反复)通过纯数字模拟被检验。第二案例研究介绍模拟为反复的集成方法就各种各样的时间步和重复的改正数字而言与二个上述的集成方法重复了的10混血儿的结果。在这些测试的物理基础由single-degree-of-freedom(SDOF)组成有提供可重复的highlynonlinear行为包括的可替代的钢赠券的伸臂列破裂类型力量和僵硬降级。以防学习三，有重复的改正数字的含蓄的Newmark被申请1:2的混合模拟放大包括一个相对复杂的非线性的数字基础的钢时刻框架。最后，一个更复杂的数字基础被构造联合到一个1:2规模钢严肃框架的一个混合模型的一个片刻框架的一个非线性的计算模型考虑。最后二案例研究在一样的porotype结构和步和重复的固定数字仔细在预告测验模拟被检验的时间的选择上被进行。产生失衡力量被用作一个索引追踪平衡错误并且预言模拟的精确性和稳定性。

简介：这份报纸讨论盘子使遭到了到强风负担的薄增强的水泥(RC)的倒塌模式。扩大众所周知的塑料模式的方法分析，不是仅仅完美塑料的盘子，而且RC盘子，调查因为板以前可能在上面、更低的表面上被击碎，在倒塌模式上裂开的材料的效果被需要塑料模式充分发展，创造倒塌模式形状的一种意外类型。一个新失败模式被数字分析在这份报纸建议并且验证。新模式是裂开的材料的结果并且在RC板的反应机制上有不可以忽略的效果到强风负担。

简介：Therecenttrendofvehicledesignaimsatcrashsafetyandenvironmentally-friendlyaspect.Forthecrashsafetyaspect,theenergyabsorbingmembersshouldabsorbcollisionenergysufficientlybutfortheenvironmentally-friendlyaspect,thevehiclestructuremustbelightweightinordertoimprovethefuelefficiencyandreducethetailgasemission.Therefore,thelightweightofvehiclemustbeachievedinasecuringsafetystatusofcrash.Analuminumorcarbonfiberreinforcedplastics(CFRP)isrepresentativeoneofthelight-weightmaterials.BasedontherespectivecollapsebehaviorofaluminumandCFRPmember,thecollapsebehaviorofhybridthin-walledmemberwasevaluated.ThehybridmembersweremanufacturedbywrappingCFRPprepregsheetsoutsidethealuminumhollowmembersintheautoclave.BecausetheCFRPisananisotropicmaterialwhosemechanicalproperties,suchasstrengthandelasticity,changewithitsstackingcondition,theeffectsofthestackingconditiononthecollapsebehaviorevaluationofthehybridthin-walledmemberweretested.Thecollapsemodeandenergyabsorptioncapabilityofthehybridthin-walledmemberwereanalyzedwiththechangeofthefiberorientationangleandinterfacenumber.

简介：在强风负担下面的钢框架结构的进步倒塌用LS-DYNA被调查。多材料Eulerian和Lagrangian联合算法被采用。联合有限元素模型的液体结构被建立它为为模仿空气和TNT爆炸材料模仿钢框架结构和水泥磨擦的、多重淡色啤酒元素由Lagrange元素组成。强风压力波浪繁殖，结构的动态回答和变丑的数字模拟，和万一爆炸的五故事的钢框架结构的进步倒塌接近上面的地面被执行。数字分析证明Lagrangian和Eulerian联合算法在结构上在媒介和强风负担效果给了冲击波繁殖的好模拟。受到强风负担的列可以崩溃由砍让步而非旁边曲折变丑。到在前面钢框架结构的列的钢横梁的柱和关节产生了受到集中的强风波浪的庞大的塑料变丑，并且柱输了带能力，随后导致整个结构的倒塌。联合在结构的变丑和液体负担之间的影响很好的途径模仿了结构的进步倒塌过程，并且为在强风负担下面分析钢框架结构的倒塌机制提供了一个有效工具。

简介：OwenHarries,Editor-in-ChiefoftheAmericanmagazineNationalInterest,oncesaidthatAmericans,formanyyears,hold'apendulumswingofalternatingattitudes,nowromanticizingnowdemonizingChina'.FollowingtheendoftheColdWar,therehavebeendrasticchangesintheUnitedStatesandtheWestern

简介：Thegrowthandcollapsebehaviorsofasinglecavitationbubblenearaheatedwallanditseffectontheheattransferarenumericallyinvestigated.Thepresentstudyisdesignedtorevealthemechanismofcavitationenhancedheattransferfromamicroscopicperspective.Inthesimulation,thetime-dependentNavier-Stokesequationsaresolvedinanaxisymmetrictwo-dimensionaldomain.Thevolumeoffluid(VOF)methodisemployedtotracktheliquid-gasinterface.Itisassumedthatthegasinsidethebubbleiscompressiblevapor,andthesurroundingliquidisincompressiblewater.Masstransferbetweentwophasesisignored.Thecalculatedbubbleprofileswerecomparedtotheavailableexperimentaldata,andagoodagreementwasobtained.Then,therelationshipamongbubblemotion,flowfieldandsurfaceheattransfercoefficientwasanalyzed.Onthisbasis,theeffectsofsuchfactorsastheinitialdistancebetweenthebubbleandthewall,theinitialvaporpressureandtheinitialbubblenucleussizeontheheattransferenhancementarediscussed.Thepresentstudyishelpfultounderstandtheheattransferphenomenoninpresenceofcavitationbubbleinliquid.

简介：0IntroductionTheJapaneseIslandsconsistoffivevolcanicarcs(Fig.1).TheNorth-EastandSouthWestJapanarcstogetherformtheHonshuarc,towhichtheKurilearcjoinsatHokkaido,whereastheIzu-MarianaarcjoinsatIzu-FossaMagna,andtheRyukyuarcjoinsatKyushu.Theseregionswherevolcanicarcsconverge,aretermed'islandarcjunctions'.

简介：DearContributors,ReadersandFriends:2011milestonesthetenthanniversaryoftheJournalofEarthquakeEngineeringandEngineeringVibration.wefirstwanttotakethisopportunitytoexpressourgratitudetothoseretiringmembersoftheEditorialBoardfortheirvaluablecontributionsinthepast,andtowelcomethosewhojoinedtheEditorialBoardthisyear.AswementionedinourmessagetoyouinDecember2010,effective20ll,thejournalisofficiallyco-sponsoredbytheHuixianEarthquake

简介：Thispaperaimstostudytheoscillationofasparkgeneratedsubmergedbubblelocatednearorinsideacircularaperturemadeinaflatplateusinghigh-speedvisualizationtechnique.Inthecaseofabubbleoscillatingnearanaperturetheinitialfreesurfaceofthewaterwassetatthebottomsurfaceoftheplate.Theefectsofaperturesizeandbubblefreesurfacedistanceonthebubblebehavioraswellasontheensuingdropletdynamicsareinvestigated.Itwasfoundthatthedirectionofthebubblereentrantjetwastowardstheapertureorawayfromitrespectivelywhenthenormalizedaperturesizewassmallerorgreaterthanacertaincriticalvalue.Inaddition,atoroidalvortexringwasobservedtoform,whichrotatedinwardsasitmovedawayfromtheaperture.Itwasalsofoundthatifthebubblewasinceptedatadistancesufcientlyawayfromasupercriticalsizeapertureasingledropletcouldbeproduced.Inthecaseofabubbleinitiatedinthemiddleofacircularaperturesubmergedjustbeneaththewaterfreesurface,thebubblewasfoundtotaketheshapeofanellipsoidduringitsexpansion.Thenareentrantjetwasinitiatedandpiercedthebubblefromitstopside.

简介：WithvonMisesyieldcriterion,theloadingrangeofNetSectionCollapse(NSC)Criteriaisextendedfromcombinedtensionandbendingloadingstocombinedbending,torsionandinternalpressureloadings.AnewtheoreticalanalyzingmethodofplasticlimitloadforpressurepipewithincompleteweldingdefectsbasedontheextendedNSCCriteriaispresentedandthecorrelativeformulasarededuced,theinfluencesofpipecurvature,circumferentiallengthanddepthofincompleteweldingdefectsontheplasticlimitloadofpressurepipeareconsideredaswellinthismethod.Meanwhile,accordingtotheorthogonalexperimentaldesignmethod,theplasticlimitloadsarecalculatedbythefiniteelementmethodandcomparedwiththetheoreticalvalues.Theresultsshowthattheexpressionsofplasticlimitloadofpressurepipewithincompleteweldingdefectsunderbending,torsionandinternalpressurebasedonextendedNSCcriteriaarereliable.Thestudyprovidesanimportanttheoreticalbasisfortheestablishmentofsafetyassessmentmeasuretowardspressurepipewithincompleteweldingdefects.