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简介:Whenoneendofanair-dryigneousrockblockwasuniaxiallyloadedinlaboratory,thereappearedanelectromotiveforcethatmadeelectriccurrentsflowfromthestressedvolumetotheunstressedvolume.Quartz-freerockssuchasgabbroalsogeneratedthisforce,strongerthanquartz-bearingrockssuchasgranite.Thisindicatesthatthepiezoelectriceffectofquartzandtheelectrokineticeffectofporewaterdonotmakealargecontributiontowardgeneratingtheelectromotiveforce.Wefocusonperoxybondthatisoneoftheabundantlatticedefectsinigneousrock-formingminerals.Whenmechanicalloadingdeformsthelatticestructurearoundthisdefectandbreaksitsbond,itsenergylevelschangeandactlikeanaccepter.AsanelectronistrappedatthisdefectfromaneighborO2-site,apositiveholeisactivatedthere.Theyattempttodiffusetowardtheunstressedvolumethroughthevalencebandandaresimultaneouslyaffectedbytheattractiveelectricforcewiththeelectronstrappedinperoxybonds.Thisleadstoapolarizationinthestressedvolumeandthegenerationofelectromotiveforcebetweenthestressedandunstressedvolumes.SimilarelectromotiveforcemaybegeneratedintheEarth’scrustwhereinhomogeneousstress/strainischanging.
简介:Amethodtocalculatethestationaryrandomresponseofanon-classicallydampedstructureisproposedthatfeaturesclearly-definedphysicalmeaningandsimpleexpression.Themethodisdevelopedinthetrequencydomain.Theexpressionoftheproposedmethodconsistsofthreeterms,i.e.,modalvelocityresponse,modaldisplacementresponse,andcoupled(betweenmodalvelocityandmodaldisplacementresponse).Numericalresultsfromtheparametricstudyandthreeexamplestructuresrevealthatthemodalvelocityresponsetermandthecoupledtermareimportanttostructuralresponseestimatesonlyforadynamicsystemwithatunedmassdamper.Intypicalcases,themodaldisplacementtermcanprovideresponseestimateswithsatisfactoryaccuracybyitself,sothatthemodalvelocitytermandcoupledtermmaybeignoredwithoutlossofaccuracy.Thisisusedtosimplifvtheresponsecomputationofnon-classicallydampedstructures.Forthewhitenoiseexcitation,threemodalcorrelationcoefficientsmclosedformarederived.Toconsiderthemodalvelocityresponsetermandthecoupledterm,asimplifiedapproximationbasedonwhitenoiseexcitationisdevelopedforthecasewhenthemodalvelocityresponseisimportanttothestructuralresponses.Numericalresultsshowthattheapproximateexpressionbasedonwhitenoiseexcitationcanprovidestructuralresponseswithsatisfactoryaccuracy.
简介:ThemaintechnicalbackgroundsandrequirementsareintroducedwithregardtoearthquakegroundmotiondesignparametersinseveraldomesticandAmericanstandards,codesandguidesinvolvedintheseismicanalysisanddesignactivitiesofnuclearpowerplantsinChina.Basedontheresearchresultsfromsiteseismicsafetyevaluationofdomesticnuclearpowerplantprojectsinthelastyears,characteristicsanddifferencesofsitespecificdesignspectraareanalyzedincomparisonwithstandardresponsespectra,andthesuitabilityofstandardresponsespectrafordomesticnuclearpowerplantprojectsisdiscussed.
简介:IntroductionThrough20-oddyears’observationandstudyafterthe1976Tangshangreatearthquake,theseismo-electromagneticradiationprec...
简介:一个核电厂的抑制容器是最后障碍阻止核反应堆放射。Aseismic安全分析是适当抑制容器设计的关键。有一个半无限的有弹性的基础和腱的实际安排的一个对的具体抑制容器(PCCV)模型被建立了在地震负担和内部压力下面分析CPR1000PCCV结构的aseismic能力。为有水泥的对的腱和它的相互作用建模的一个方法被建议,对的腱的轴的力量证明模拟合理、精确。数字结果证明为具体结构,在设备开口附近并且在戒指横梁附近的柱体墙底部的地点是有大主要应力的批评地点。具体裂缝在0.50g的山峰地震运动下面发生在PCCV柱体墙的底部,然而,PCCV处于一个有弹性的状态基本上是静止的。而且,具体裂缝在设计下面发生在设备开口附近0.4MPa的内部压力,而是钢班机仍然在有弹性的阶段并且它的防漏功能稳固被验证。结果为抑制容器的分析和设计提供基础。
简介:Thisstudyinvestigatestheeffectivenessofthenon-smoothsemi-activecontrolalgorithmonsuppressingthevibrationperformanceofabuildingstructuresubjectedtoseismicwaves.AccordingtotheLyapunovstabilitytheory,ithasbeneproventhatthenon-smoothsemi-activecontrolalgorithmcanachieveafinite-timestabilityofthevibrationrelativetotheisolationlayerofabuildingstructure.Throughnumericalsimulationoftwobuildingswithdifferentparameterssubjectedtotheinputofaseismicwave,thevibrationconditionsofpassivecontrol,LQRsemi-activecontrolandnon-smoothsemiactivecontrolarecomparedandanalyzed.Thesimulationresultsshowthatthenon-smoothsemi-activecontrolalgorithmhasabetterrobustnessandeffectivenessinrestrainingtheimpactofearthquakesonthestructure.
简介:TherigidcentralbuckleemployedintheRunyangSuspensionBridge(RSB)wasthefirsttimeitwasusedinasuspensionbridgeinChina.ByusingaspectralrepresentationmethodandFFTtechniquecombinedwithmeasureddata,a3Dfluctuatingwindfieldconsideringthetowerwindeffectissimulated.AnovelFEmodelforbuffetinganalysisisthenpresented,inwhichaspecificuser-definedMatrix27elementinANSYSisemployedtosimulatetheaeroelasticforcesanditsstiffnessordampingmatricesareparameterizedbywindvelocityandvibrationfrequency.Anonlineartimehistoryanalysisiscarriedouttostudytheinfluenceoftherigidcentralbuckleonthewind-inducedbuffetingresponseofalong-spansuspensionbridge.Theresultscanbeusedasareferenceforwindresistancedesignoflong-spansuspensionbridgeswitharigidcentralbuckleinthefuture.
简介:增强的水泥(RC)框架结构是主要普通的使用的结构的系统之一,并且他们的地震表演被柱和横梁的表演大部分决定。这篇论文描述十列和三个横梁标本的水平周期的装载测试,其中一些根据当前的地震设计代码和其它被设计,根据早非地震的中国设计代码被设计,瞄准报导在Wenchuan地震期间观察的损坏或崩溃的RC框架strctures的行为。轴的负担比率的效果,砍跨度比率,和磁滞现象行为,韧性和损坏进步上的横向、纵的加强比率在试验性的学习被合并。测试结果显示non-seismically设计的列出现早熟砍失败,和收益更大的最大的剩余裂缝宽度和更多水泥spalling与地震联盟者设计列比。另外,纵的钢加强美国南北战争时南军士兵艺术严重地被弄弯。轴的负担比率并且砍证明是当纵的加强比率在柱韧性上有仅仅次要的效果,但是在横梁韧性上展出了更多的影响时,影响韧性,裂缝开始宽度和关门能力的最重要的因素的跨度比率。最后,横向的加强比率没影响最大的剩余裂缝宽度,地震联盟者的关门能力设计列。
简介:在在一个长期的服务时期上的好攻击的海洋的环境,沿海的桥不可避免地由于高海盐和湿度支撑导致腐蚀的损坏。这份报纸调查沿海的桥的力量减小,特别沿着桥墩的高度集中于不一致的腐蚀的效果。首先,腐蚀开始时间和加强和水泥的降级在海洋的环境为桥墩被分析。为了调查水泥的各种各样的损坏模式,盖住,有纤维房间的一个discretization方法在轴的力量和弯曲时刻的联合下面在大气的地区和潮汐的地区被用于桥墩的剖面图的精明的时间依赖者相互作用图。第二,这些变老的结构的shear力量被分析。数字模拟显示具体的墩的力量从腐蚀开始经历戏剧的减小到具体盖子的spalling。在骚动和潮汐的地区的力量损失比在大气的地区什么时候组织服务时间,被假定是一样的是更重要的。
简介:Thenon-tidalvariationgainedfromcontinuousgravityobservationsinstationsusuallyreflectstheregionalcontinuousgravitychanges.Inthispaperwefocusonstudyingthenon-tidalvariationofBaijiatuanstation,Beijingwheretherearetwodifferentgravimeters(namely,L&R-804andPET-031).Basedontheoriginalrawtidalrecordsoftwogravimetersfrom2008to2011,wefirstremovevariousinterferencefromrawdatabythestandardproceduresoftware-Tsoft;thenwemodelthesolidearthtides,oceantidalloadingandpoletidethroughrelatedparameters;afterthatweadoptanewsegmentedpolynomialfittingmethodbasedonTsofttofitthecomplexdriftofspringgravimeter;andfinallywecalculatetheatmosphericloadingeffectsbyalinearregressionmodel.Afteraseriesofprocessingwegainthenon-tidalvariationofthetwogravimetersatBaijiatuansite,Beijing.Furthermore,toanalyzethenon-tidalvariationpreliminarily,westudythemaincomponentofrelatedtidaldatabypowerspectraldensity.Comparingthenon-tidalvariationoftwodifferentgravimeters,wefindseasonalfluctuationsinnon-tidalresults,whichareinaccordancewiththewaterstoragechange.Therefore,wetakeintoaccounttherelevanceofgravitychangesandwaterstoragebasedonthegravitydataofGRACEandwaterdataoftheCMAPmodelfrom2003to2011atdifferentsitesintheChinesemainland(Beijing,Chengdu,ShenyangandShiquanhe),andmakeapreliminaryanalysisontherelationshipbetweengravitychangesandwaterstorage.
简介:Athird-ordercorrectionwasrecentlysuggestedtoimprovetheaccuracyofthehalf-powerbandwidthmethodinestimatingthedampingofsingleDOFsystems.Thispaperanalyzestheaccuracyofthehalf-powerbandwidthmethodwiththethird-ordercorrectionindampingestimationformulti-DOFlinearsystems.Dampingratiosinatwo-DOFlinearsystemareestimatedusingitsdisplacementandaccelerationfrequencyresponsecurves,respectively.Awiderangeofimportantparametersthatcharacterizetheshapeoftheseresponsecurvesaretakenintoaccount.Resultsshowthatthethird-ordercorrectionmaygreatlyimprovetheaccuracyofthehalf-powerbandwidthmethodinestimatingdampinginatwo-DOFsystem.Inspiteofthis,thehalf-powerbandwidthmethodmaysignificantlyoverestimatethedampingratiosoftwo-DOFsystemsinsomecases.
简介:这个地点和结构的参数无常的动态效果的考虑被标准在大多数国家为核电厂(NPP)要求。抗地震的标准提供二个基本方法分析参数无常。手工地直接处理计算地板反应系列(皇家学会会员)确定的途径珍视是第一个方法。第二个方法是执行概率统计的FRS的分析根据蒙特卡罗方法结果。二个方法能仅仅反映不明确的参数的全面效果,并且结果不能为某个参数影响和贡献被屏蔽。在这研究,基于NPP的地板反应系列的动态分析,为各种各样的不明确的参数的估计的影响的一个全面索引被介绍并且推荐,包括关联系数,回归斜坡系数和旋风秋千。在NPP地震标准补偿指导的缺乏,建议方法能有效地被用来从敏感,尖酸和统计秋千的方面评估各种各样的参数的贡献关联。最后,例子被提供从系统、直觉的观点验证指示物的集合,例如NPP的皇家学会会员的结构参数和贡献的影响的无常。这个索引对参数的不同类型敏感,它为评估为NPP要求的抗地震的参数提供一种新技术。
简介:Basedonthemodelsofnon-uniformearthquakedistributioninthepotentialsource,theseismiczonationofWesternPanzhihuaandCentralandSouthernShanxiProvinceisstudied.Theresultsshowthattheusualuniformdistributionmodelmayunderestimatetheseismicriskandresultinareductionoftheareasofhighintensity.Theinfluenceofeachnon-uniformprobabilisticdistributionmethodontheresultofseismiczoningisdiscussed.