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500 个结果
  • 简介:摘要本文分别对MARC和DC的发展和特点进行了详细的阐述,并比较分析了其不同点。在此基础上说明了当今社会MARC、DC并存的的意义

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  • 简介:Thegasdynamicandelectromagneticfactorsaffectingthepositionofarcrootsinatubulararcheaterareanalyzed.Magnitudesofthevariousfactorsareestimatedthroughnumericalmodelling,andtheoverallactiononthearcassessed.Itisfoundthattheactionsonthearcintherearelectrodecanbebalancedinastablemannerandthearcrootcanbestabilizedatacertainaxialposition.Inthefrontelectrode,thevariousfactorscannotbebalanced,andthearerootcanonlystaywithintheelectrodethroughthemechanismofrecurrentshunting.Theseconclusionsagreewithexperimentalobservations.

  • 标签: ARC HEATER ARC STABILIZATION ARC POSITION
  • 简介:煤气的金属弧焊(GMAW)的数字模型正在试着联合液体(VoF)的弧和体积的magnetohydrodynamics(MHD)模型的电流金属转移当模特儿。他们忽视蒸发并且为弧区域假定氩气氛,因为它是为煤气的钨弧焊的模型的普通实践。这些模型在20000K和类似于钨的温度分布上面预言温度惰性的气体(TIG)弧。然而,在GMAW弧的当前的分光镜的温度大小表明低得多的弧温度。与TIG弧相对照,他们发现了光线的温度分发的中央本地最小。纸论述考虑金属蒸汽的一个GMAW弧模型并且它在与试验性地观察的温度的一个很好的协议。而且,模型能第一次在光线的温度和光线的电流密度分布预言本地中央最小。向轴的方向焊接火炬,工作片,电线和弧(液体领域)的对称的模型象在氩的狂暴的混合和金属蒸汽的热demixing一样实现MHD。从模拟获得的铁蒸汽的集体部分在2000~5000K在弧的穗上在弧核心和另一累积显示出累积。demixing效果导致在这二个区域之间的铁的很低的集中。敏感分析证明运输的影响和金属蒸汽的放射性质喂。最后模型预言与Zieliska等的测量结果相比。

  • 标签: 数值模型 金属蒸气 惰性气体 电弧焊接 ANSYS 电弧行为
  • 简介:我们考虑决定作为生气的节有一条开的弧的薄绝缘的无限的柱体的形状的反的散布问题。假设电场在TM模式被极化,这为在R2在一条开的弧的外表定义的Helmholtz方程导致一个混合边界价值问题。我们假定弧混合了Dirichlet阻抗边界状况,并且试着由使用因式分解方法通过远地模式恢复弧的形状。然而,我们不能使用樱桃酒介绍对待远地操作员F的基本定理,并且一些辅助操作员不得不被考虑。到我们的问题的因式分解方法的理论确认在这份报纸被给,并且一些数字结果被介绍显示出我们的方法的生存能力。[从作者抽象]

  • 标签: 分解方法 DIRICHLET 混合边值问题 逆散射问题 亥姆霍兹方程 阻抗边界条件
  • 简介:Thearcsprayingprocessisdividedintotwostages:thefirststageisatomization-sprayingstream(ASS)andthesecondoneissprayingdeposition(SD).Thenstudystatusisdescribedofbothstages'physicalmodelandcorrespondingcontrolling-equation.Basedontheanalysisofstudystatus,theconclusionasfollowsisgot.TheheatandmasstransfermodelswithtwoorthreedimensionsinASSstageshouldbeestablishedtofardeeplyanalysesthedynamicalandthermalbehavioroftheoverheatdroplet.Thestatisticslawofoverheateddropletsshouldbefurtherstudiedbyconnectingsimulationwithexperiments.MorepropervalidationexperimentsshouldbedesignedforflatteningsimulationtomodifythemodelsinSDstage.

  • 标签: 电弧喷涂 计算机模拟 数值模拟 ASS SD
  • 简介:AprototypeofPulsedPlasmaArcCladdingsystemwasdeveloped,inwhichsinglepowersourcesuppliesbothtransferredplasmaarc(TPA)andnon-transferredplasmaarc(N-TPA).BothplasmasworkinturninahighfrequencycontrolledbyanIGBTconnectingnozzleandworkpiece.TheworkingfrequencyofIGBTrangesfrom50~7000Hz,inwhichtheplasmascanworkinturnsmoothly.Higherthan500HzofworkingfrequencyissuggestedforpromotionofcladdingqualityandprotectionofIGBT.DragphenomenonofTPAintensifiesasthefrequencygoesup,whichtendstoincreasethecurrentproportionofTPAandsuppressN-TPA.TheoccupationratioofIGBTcanberegulatedfrom5%~95%,whichbalancesthepowersuppliesofbothplasmas.Anoccupationratiohigherthan50%givesadequateproportionofarccurrentforN-TPAtopreheatpowder.

  • 标签: 功率源 脉冲等离子体 等离子弧焊 IGBT 表面处理 焊接
  • 简介:Forgivendata(ti,yi),I=0,1,…,n,0=t0<t1<…<tn=1westudyconstrainedinterpolationproblemofFavardtypeinf{‖f'‖∞|f∈W2∞[0,1],f(ti)=yi,i=0,…,n,l(f;[0,1])≤l0},wherel(f';[0,1])=∫10/1+f'2(x)dxisthearclengthoffin[0,1].Weprovetheexistenceofasolutionf*oftheaboveproblem,thatisaquadraticsplinewithasecondderivativef'*,whichcoincideswithoneoftheconstants-‖f'*‖∞,0,‖f'*‖∞betweeneverytwoconsecutiveknots.Thus,weextendaresultofKarlinconcerningFavardproblem,tothecaseofrestrictedlengthinterpolation.

  • 标签: 弧长 分割 插值 节点 二次样条
  • 简介:Thispaperpresentsanewsplinecalledarcspline.Ittakestwoarcsconnectingadjacentpointsamongasampledseries,withknowntangentalofeachsampledpoint.Thecalculationfortheparallel.thecurvelengthandthesegment-ingpointcoordinatesaresimple,thusmakingmapsymbolgenerationsimplified.When'arclet'occurs,somespecialprocessingmustbetaken.

  • 标签: arc-splines computer graphics COMPUTER-AIDED CARTOGRAPHY arclet
  • 简介:Aspectraldiagnosticsofcomplexareplasmausingmultiplespectralinformationofareself-emittingispro-posed.Thismethodisabletosimultaneouslydeterminecomponentdensities,thecorrespondingtemperatureandtheirdis-tributionsbyafewlineintensitiesmeasurent.Theprincipleofthemethodandtherelevantmeasuringsystemarede-scribed.Anequationsystemisestablishedforcomputationofthestatevariablesinareplasma.Anexperimentunderweldingareconditionismadeasanapplicationofthemethod.Theeffectsofprobableerrorsourcesonthemeasurementarealsoanalysed.

  • 标签: SPECTRAL DIAGNOSTICS COMPONENT DENSITIES WELDING ARC
  • 简介:ONARC┐TRANSITIVECIRCULANTDIGRAPHSHUANGQIONGXIANGAbstract.DenotebyCn(S)thecirculantdigraphwithvertexsetZn={0,1,2,...,n-1}andsy...

  • 标签: Circulant 两个字母并成的一个单音 弧及物
  • 简介:Thevariationinarccharacteristicsandbehaviorofmetaltransferwiththechangeinpulseparametershasbeenstudiedbyhighspeedvideocameraduringpulsecurrentflux-coredarcwelddeposition.Acomparativestudyofsimilarnaturehasalsobeencarriedoutduringflux-coredarcwelddepositioninglobularandspraytransfermodes.Theeffectofpulseparametershasbeenstudiedbyconsideringtheirmeancurrentandarcvoltage.Thearccharacteristicsstudiedbyitsrootdiameter,projecteddiameterandlength,andthebehaviorofmetaltransfernotedbythemetaltransfermodelandthedropletdiameterhavebeenfoundtovarysignificantlywiththepulseparameters.TheobservationmayhelpinunderstandingthearccharacteristicswithrespecttothevariationinpulseparameterswhichmaybebeneficialinusingpulsecurrentFCAWtoproducedesiredweldquality.

  • 标签: 电弧特性 行为研究 脉冲电流 电弧焊接 金属 低碳钢
  • 简介:Manyapplicationsofultrasonic-assistedmethodswereusedduringmetalsolidification,buttheycouldnotbeintroducedintoweldpool.Inthispaper,awayofultrasonicassistedTIGweldingisintroduced.Bydirectlyimposedultrasonicvibrationonweldingarc,thevibrationinteractswitharcplasmaandpassestotheweldpool.Measurementresultsshowthatarcpressureissignificantlyincreasedwiththeultrasonicvibrationandthearcpressuredistributionmodelsarechanged.Bead-on-plateweldingtestsonSUS304confirmthatthistechnologycaninfluencethestyleofmetalmeltingandincreaseweldpenetrationdepth.

  • 标签: 焊接工艺 焊接法 超声波 焊接操作
  • 简介:<正>CENTRALCHINAARCSERIESANDITSMETALLOGENYJiangZhenya(HubeiInstituteofGeoscience,Wuhan,430022,Hubei,P.R.China)arc,metailogeny,CentralChinaThecentralChinaarcseriesliesacrossthewholecentralChina,embodyingQinghuaiarc,Esuarc,Changjiangarc,Chuzhearc,andXianggangarc.Itisagigantictecton-icarcseries.TheseriesistheresultofnorthandsouththrustingofhorizontaldiferrentialbucklingundertheuniversalnorthandsouthcompressingineasternChina.ItbeganatYingzhimovement,formedatthefirststageofYanshanmovement,andsolidifiedatthesceondstageofYanshanmovement.Theseriescontrollssedimentation,exogenicdeposits,magmatism,andendogenicdeposits.Menawhileitaffectsmordentopography,alluvialsystem,andclimate.

  • 标签: ARC metailogeny CENTRAL China
  • 简介:AnexperimentalsystemofACarcdischargeinwaterwasdesignedwithpole-poleelectrodesandapeakvoltageof1500Vandatestcircuitwassetupusingvirtualinstrumenttechnology.ThemechanismofanACplasmaarcgeneratedinwaterwasanalyzed.ThevoltagecurrentcharacteristicoftheACplasmaarcwasobtainedfromthewaveform.Thetemperaturecharacteristicwastestedwithaspectrumdiagnosissystem,andtheeffectofdifferentelectrodematerialsonthestrikingvoltageandpeakcurrentwasanalyzed.Theresultsshowthatwhenapowersupplyof6kWisappliedonelectrodeswithagapof2mminwater,thestrikingvoltageisfrom900Vto1300V,thearcvoltageisfrom40Vto100V,thearccurrentisfrom2Ato7A,andthezerorestperiodisfrom1msto2ms.Inaddition,thearcvoltageandcurrentaredifferentforelectrodesinaluminum,copperandstainlesssteel.Thearcvoltageislowerandthecurrentishigherforanaluminumelectrodethanthoseforcopperandstainlesssteelones.Thehighesttemperatureofthearcis7643K.

  • 标签: 交流等离子体 等离子体特性 电压电流特性 电极材料 峰值电压
  • 简介:Thekeyproblemfornumericalsimulationofplasmaarcwelding(PAW)processistodevelopasuitableandadaptivevolumetricheatsourcemodewhichreflectsthephysicalcharacteristicsofkeyholePAW.Tothisend,thekeyholegeometryunderdifferentPAWprocessconditionsmustbepredicted.Inthispaper,amathematicalmodelfordeterminingthekeyholeshapeisdevelopedwithconsideringthemassandmomentumconservationofthein-keyholeplasmajetaswellasthepressureequilibriumattheplasmajet/liquidmetalboundary.AsuitableheatsourcemodelrelatedtothekeyholeshapeisappliedtothecalculationofPAWwelddimensions.Thepredictedresultsareingoodagreementwiththeexperimentalones.

  • 标签: 等离子弧焊 小孔 几何结构 数值分析
  • 简介:Throughtheinvestigationontraditionalarcstudweldingprocess,anewweldinggunanditscontrolsystemweredevelopedinthispaper.Thesteppingarcstudweldinggunwasmainlymadebyasteppingmotorasactuatingunitandascrew-drivendeviceasmovingunit.AcontrolsystemwithaMCS-51single-chipmicrocomputerasmaincontrolcomponentwasusedtorealizethenewstudweldingprocedure.Thisnewweldingprocesswithsteppingstudweldinggunisnamedassteppingarcstudwelding.Inthenewweldingprocess,thestudactioncanbelookedasconstitutedbysomemicrosteps.Thesettingandadjustingofthesteppingarcweldinggunbehaviorparametersareaccomplishedindependently.Itisindicatedfromtheresultsofprocesstestsandbendingtestthatthesteppingarcstudweldingprocessispracticable.

  • 标签: 单片机 螺柱电弧焊 焊枪 焊接自动化
  • 简介:本文介绍了应用于金属互联工艺的ARC(抗反射层或防反射层)技术.通过对抗反射层基本原理的说明,结合工艺实验,深刻地理解ARC技术.最后给出了可以用于0.5μm工艺生产的ARC结构及用于衡量ARC性能的参数.

  • 标签: ARC 光刻 抗反射