简介:Thenumericalinvestigationofregularwavesinteractingwithasubmergedhorizontaltwin-platebreakwaterispresentedinthispaper.Anumericalmodelwithanabsorbingwave-makerisestablishedbasedontheVOFmethod.Thevalidityofthemodelisverifiedbyexperimentalresults.Comparisonsbetweenthenumericalandexperimentalresultsshowthatboththewatersurfaceprofilesandthewave-inducedpressurescanbemodeledaccurately.Wavedeformationoverthebreakwater,waterparticlevelocitiesaroundthebreakwater,andthewave-inducedpressuresonthestructurearenumericallyinvestigated.Thepressureamplitudesofthefundamentalandsecondharmonicsonthemodelsurfaceareexaminedinvariouswaterdepths.Thecomputedandexperimentalresultshaverevealedthatthehigherfrequencycomponentsaregeneratedattheonshoresideofthebreakwater.Furthermore,thecomputedresultsdemonstrateacirculatingflowformedattheonshoresideofthebreakwater.
简介:Platestructuresareemployedasimportantstructuralcomponentsinmanyengineeringapplications.Hence,assessingthestructuralconditionsofin-serviceplatestructuresiscriticaltomonitoringglobalstructuralhealth.Modalcurvature-baseddamagedetectiontechniqueshaverecentlygarneredconsiderableattentionfromtheresearchcommunity,andhavebecomeapromisingvibration-basedstructuralhealthmonitoringsolution.However,computingerrorsarisewhencalculatingmodalcurvaturesfromlateralmodeshapes,whichresultfromunavoidablemeasurementerrorsinthemodeshapesasidentifiedfromlateralvibrationsignals;thismakescurvature-basedalgorithmsthatusealateralmeasurementonlytheoreticallyfeasible,butpracticallyinfeasible.Therefore,inthisstudy,long-gaugefiberBragggratingstrainsensorsareemployedtoobtainamodalcurvaturewithoutanumericaldifferentiationprocedureinordertocircumventthecomputingerrors.Severaldamageindicesbasedonmodalcurvaturesthatweredevelopedtolocatebeamdamageareemployed.Bothnumericalandexperimentalstudiesareperformedtovalidatetheproposedapproach.However,althoughpreviousstudieshavereportedrelativesuccesswiththeapplicationofthesedamageindicesonasimplebeam,onlyonedamageindexdemonstratedthecapabilitytolocatedamagewhenthestiffnessofthelocalregionchangednearthesensor.
简介:TheproblemofshiphullplateprocessingsurfacefairingwithconstraintsbasedonB-splineissolvedinthispaper.ThealgorithmforB-splinecurvefairingwithconstraintsisoneofthemostcommonmethodsinplanecurvefairing.Thealgorithmcanbeappliedtoglobalandlocalcurvefairing.Itcanconstraintheperturbationrangeofthecontrolpointsandtheshapevariationofthecurve,andgetabetterfairingresultinplanecurves.Inthispaper,anewfairingalgorithmwithconstraintsforcurvesandsurfacesinspaceispresented.Thenthismethodisappliedtotheexperimentsofshiphullplateprocessingsurface.Finallynumericalresultsareobtainedtoshowtheefficiencyofthismethod.
简介:Temporalmodedirectnumericalsimulationwasdonefortheprocessoflaminar-turbulenttransitioninanincompressibleboundarylayeronaflatplate.Theanalysisoftheresultsshowedthatduringthebreakdownprocessoflaminar-turbulenttransition,themodificationofthemeanflowprofilebythedisturbancesledtoaremarkablechangeinitsstabilitycharacteristics,manifestedinthesignificantenlargementofthelinearunstablezoneandthemaximumamplificationrate,andledtothatmanymoredisturbanceswereexcitedandenhancedrapidly,correspondinglytheturbulentenergyalsoincreasedrapidly,andthemeanflowprofilesevolvedswiftlyfromlaminartoturbulent.Itwasalsofoundthatiftheobliquewavesintheinitialdisturbancesdidnotformsymmetricalpairs,thesubsequentspan-wisemeanvelocitieswould,ingeneral,benonzeroduetononlinearinteraction,whichwouldhaveagreateffectonthestabilitycharacteristicsandalsoimpliedthattheturbulenceobtainedbydirectnumericalsimulationmightnotbefullyarandomprocess.
简介:ThedimensionvariationofB610EsteelduringthequenchingandtemperingprocesswassimulatedbyABAQUS,thecoefficientofheattransferduringquenchingwasverifiedbytheburiedthermocoupletestandthetrendofthedimensionvariationduringthequenchingprocesswasalsocalculatedbyABAQUS.Itwasshownbythecomparisonofsimulatedresultsandindustriallymeasuredresultsthatonlythesimulationofthicknessandwidthvariationwasaccurate,whilelengthvariationneededfurthersimulation.Besides,thedimensionvariationtrendwasidenticalwiththemeasuredresults.
简介:客观:在山羊胫节在外皮的骨头灌注上把点contact-dynamiccompression板(PC-DCP)和它的效果的机械性质与动态压缩盘子(DCP)的作比较。方法:二十匹配的新鲜山羊胫节被使用。一个横向的破裂模型被建立。有在骨折结束之间的3mm间隙星际的破裂分别地与DCP和PC-DCPs服从于固定,然后,thefour指弯曲测试和扭转测试被进行把PC-DCP的机械性质与DCP的作比较。另一13只性成熟的山羊与DCPsand经历了固定PC-DCPs,分别地在未经触动的双边的胫节中间柄。Ischemic地区在四个次点被观察(1天,在操作以后的2,6,和12个星期)用disulphine蓝染色技术。结果:在机械性质没有重要差别,例如拐弯抵抗和扭转抵抗,在DCP和PC-DCPs之间。有天,在操作以后的2,和6个星期在DCP固定的方面上,在坚持的板下面的外部外皮的骨头局部缺血,和这个条件没在操作以后逆行直到12个星期。在PC-DCP固定的方面上,然而,外皮的骨头局部缺血仅仅在螺丝钉洞并且在PC坚果的接触地点的圆周发生了1天在操作,和它在操作以后消失在2个星期以后。结论:PC-DCP有类似的简历DCP的机械性质,但是比常规盘子对本地骨头血循环不太有害。
简介:假定在厚度和光线的方向两个都与一条指数的法律变化的材料性质,axisymmetric弯曲二方向性的机能上地分级的通报和环形的盘子在这篇论文用半分析的数字方法被学习。盘子的偏转和压力被介绍。数字结果显示出井精确性和方法的集中。与有限元素方法相比,半分析的数字方法与在计算效率的大优点。而且,二方向性的机能上地分级的环形的板弯曲的axisymmetric上的学习证明如此的盘子用各向同性的同类的材料或一个方向性的机能上地分级的材料做的比那些有更好的性能。二方向性的机能上地分级的材料是一个方向性的机能上地分级的材料的一种潜在的选择。并且材料和结构的综合设计能确实在二方向性的机能上地分级的材料被完成。
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简介:试验性的调查被执行在与不同模式的短矩形的板鳍的数组(7脳7)适合的endwall上学习液体流动和热转移特征(co尖并且之字形)为不同沥青比率。实验在50公里高度的矩形的管被进行因为雷纳兹数字的空气流动基于相等的直径和管的空气速度从18750~62500。红外线的图象分析技术被采用在鳍底,endwall和全面表面上弄明白本地热转移系数的特征。在短矩形的盘子附近的流动模式被导致设想荧光灯在一条水隧道和纵的旋涡的染料被观察。为co尖的模式在流动方向原因热转移改进增加在盘子之间的距离,当减少时为之字形模式的距离原因热转移改进。有沥青比率2的之字形模式被发现比调查的任何另外的案例在发情转移改进更有效。关键词红外线的图象-矩形的板-传送对流热转移-流动可视化CLC数字TK124
简介:Thispaperproposesanewtectonicpatternofthedeep-seatedstructuresinChinaanditsadjacentareas(includingtheT-A-BsystemoftheRyukyuIslands).Thisisbasedonstudiesofthegravityfieldandgravityinversioncoupledwiththesummationofthemostrecentachievementsingeophysicalstudies.Fromaplate-tectonicpointofview,themetallogeniccharacteristicsandtheirindicationsatdepth,aswellasrelevantgeophysical-geologicalcharacteristicsoffourtectonicenvironmentsoftheChinesecontinentareanalysed,andaclassificationofcompositemetallogenicprovincesandbeltsandpredictionofmetallogenicprospectsaremade.TheauthorextendstheKunlun-Qilian-QinlingtectonicbelttotheT-A-BsystemoftheRyukyuIslandsthroughtheNWdeepboundaryoftheHangzhouBay,andalsoproposesthefollowingbasicviews’themigrationandsuperpositionoftectonicenvironmentsledtotheformationofacompositemetallogenicsystem;thechangeinthetectonicenvironmentresulted
简介:parabolized稳定性方程(PSE)被导出在种Blasius边界层学习粒子沉重的流动的线性稳定性。稳定性特征为各种各样司烧数字;粒子集中在用不安方法数字地解决方程以后被分析;有限差别。非平行的术语的包括与平行流动相比在批评雷纳兹数字的价值生产减小。为效果有批评价值司烧数字,;批评司烧数字在附近联合起来,;最有效的不稳定性抑制发生什么时候司烧数字具有顺序10。但是非平行的术语的存在不在气体影响粒子的角色。也就是说好粒子的增加(司烧数字比1小得多)当时,减少批评雷纳兹数字粗糙的粒子的增加(司烧数字比1大得多)提高它。非平行的吝啬的流动的效果为飞机平行的盒子与那一样的品质上流动。
简介:Basedonthetheoryforsmallfieldssuperposedonrelativelylargerfieldsinanelectroelasticbody,&theoreticalanalysisisperformedonacircularplatethickness-shearcrystalresonatorsealedinacircularcylindricalshellforpressuremeasurement.Asimpleexpressionisobtainedforpressureinducedfrequencyshiftsintheresonator,whichisexaminedfordesignoptimization.Numericalresultsshowthatthefrequencyshiftsdependlinearlyonthepressure,andthatapressuresensorwithasofteroutershellorasmallerthicknessratioofthecrystalplatetotheoutershellhashighersensitivity.
简介:AnewlydevelopedZfracturecriterionforthecompositematerialswasintroduced,thenewconceptsofin-planeaveragestrain,in-planedilatationalstrainenergydensityfactorandreciprocalcharacteristicfunctionwerepresented.ManyexperimentalresultsshowthattheZfracturecriterioncanbewellusedtopredictthecrackpropagatingdirectionformodeⅠcrackincarbon-fiberreinforcedcompositelaminates.
简介:Themillrollerbeatingismadeupofaninternalring,middlerollsandanexternalring,theanalysisofwhiehisamulti-bodiescontactproblem.Inthispaper,basedonthethree-dimensionalelasticcontactBEMwithoutfriction,andusingthestructuralcharacteristicsofrollerbearings,middlerollsarede-scribedbyelasticplateunitsofdifferentshapes,whichisplacedontheinternalring.Thediscontinuoustractionproblemofthecontactelementcanbedealtwithbythetractionsub-elementmethod.Thereforethecontactproblemcanbechangedfroinoneofmulti-bodiestooneoftwo-bodies.Asanelasticdeformationoftheplateelement,itcanbecalculatedbyanelasticcontactformulaandisregardedananequivalentgaptobeputintothetotalmatrixequality.Theface-to-facecontactconditionofdisplacementandtractionontheelementwillnerveastheconvergencejudgingcondition.Soconvergencesolutioncanbeobtainedbeforeanygeometryinconsistentonthecontactelementmaytakeplace.Therefore,thethree-dimensionaldistributionofloadofthemillrollerbearingcanbeachieved,Ithasbeenprovedthatthecalculatingmodelofthismethodisvisualizedandsimple,haslastconvergencesolutionandhigheraccuracy,makingitaneffectivenumericalmethodofdesigningandanalyzingloadcharacteristicsofthemillrollerbearing.
简介:AseriesofPS-PPACwasdevelopedandthepositionresolutionwassuccessivelyimprovedbyusinordertomeettheneedofheavyionphysicsresearch.ThePS-PPACmaybedividedintotwogroups.1PS-PPACusedforstable(ion)bearna)Doublegridpositionsensitiveavalanchechamber(DGAC)~[1].DGACconsistsof4electrodes:anodeA,cathodeC,gridsKandG,whicharemadeofwireplanes.Thesensitiveareawas25×20cm~2.Aposition