厚板多层多道焊角变形分析方法——焊接技术
8 MAINTOPICS,ABSTRACTS&KEYWORDS 2004,Vol.25,No.
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angulardistortionanalysiswasputforward.Appliedthebasicmechani2calformulasandcombinedthecauseoftheweldingdistortion,anewformulafortheangulardistortioninmulti2passweldisdeduced.TwoexamplesaboutthicklowcarbonsteelbuttweldwithasingleV2grooveandthickaluminumalloybuttweldwithdoubleV2groovesareillustrat2ed.
Keywords:welding;thickplate;weld;angulardistor2tion
al921AofusingexplosiveHOU2,Xi,LIURun2quan(DeptofNavalEng,NavalUnivofEngineering,Wuhan,China).p119123
Abstract:Specimenwasdesignedtosimulatetheweldofsubmarinepressurehullaccordingtoitsweldingprocedurne,andtheexplosivepro2cedunewasdesignedtorelieveweldingresidualstressofthespecimenaccordingtothebasicprincipleandtheexperienceofweldingresidualstressrelievingbyusingexplosivemethod.Experimentalresearchonweldingresidualstressrelievingofsteel921Awascarriedout.There2sultsshowthatexplosiverelievingbothononesideandondoublesidescanregulateandrelieveresidualstress.Thedistributionoftheresidualstressismoreregular,andtherelievingeffectofcontactexplosionisbetterthannon2contactexplosion,explosionwaveisbetterthanthebouncingrarefactionwave.Explosionondoublesidesisbetterthanononeside.
Keywords:explosivemethod;weldingresidualstress;residualstressrelieving;submarinepressurehull
Progressinvariablepolarityplasmaarcwelding CHENKe2xuan,LIHe2qi,LIChun2xu(LanzhouUniversityofTechnology,Lanzhou730050,China).p124128
Abstract:Theadvantageofvariablepolarityplasmaarcweldingisthatthecharacteristicparameterssuchasthefrequency,currentampli2tudeandDCEN/DCEPratiocanbeadjustedatwilltomeettheneedofcathodiccleaningandkeyholing.Thestatusofrealizationofvariablepo2laritycurrentwaveform,arcstability,cathodiccleaningmechanismandkeyholedetectionisintroducedinthispaper.Toensurethesynchroniza2tionbetweenprimaryandsecondarycircuitisthekeyofdual-inverter.Dual2passagecaneliminatetheinterferencebetweenmainarcandpilotarc,anddecreasethedeteriorationoftungstenelectrode.Ionsputteringorionbombardment,dielectricbreakdownandmomentarymeltingandevaporatingarethemaintheoriesofcathodiccleaningmechanism.Itis
Abstract:Angulardistortionisaseriousprobleminmulti2pass
moreimportanttomastertheregularityofcleaning.Ofallrecentdevel2opedkeyholedetectionmethods,frontsidedetectionandmulti2sensinginformationisstilltheleadingdirection.
Keywords:variablepolarityplasmaarcwelding;arcstability;ca2thodiccleaning;keyholedetection
CHENYu2(1.ShanghaiJiaotongUniversity,Shanghai200030,China;2.CaterpillarXuzhouLtd.JiansuXuzhou221004,China).p107110
Abstract:Residualplasticstrainmethodisappliedtotheplanenesspredictionoftheupperringsurfaceofgragbnetherframecarbodywhereweldsaredistributedinspatial.Formostofweldslieontheaboveofthegravity,thestructureisbendingtowardbottomafterwelding.Itisrea2sonableweldingbottomplateweldsandupperplateweldsbyturnstode2creaseoftheweldingdeformation.Residualplasticstrainmethodcannotconsidertheeffectoftheweldingsequencesontheweldingdeformation.Buttheeffectofpartsofweldsonthestructurecanbeindividualyana2lyzedbyresidualplasticstrainmethod.Calculationofthemainweldsshowedthatitisprofitfordecreasingtheplanebythecircleweldsinsegmentsandbyturns.planetheupperringsurfaceof68Itseemsnoteasytomeetmm.circlesinseg2mentsorofaretodecreasethepla2neessoftheupperKeywords:netherframe;planeness;residualplasticstrain;finiteelementmethod
MathematicalmodelofnewLCL-typemaincircuitofresonanttypesoft2switchingarcweldinginvertedpowersource DUXian2chang1,DENGZhan2feng,DUXu2chang,BAIZhi2fan(1.ChangchunInsti2tuteofTechnology,Changchun130012,China;2.TsinghuaUniversi2ty,Beijing100084,China;http://www.77cn.com.cnizhouBoilerInspectionBureau,Shan2dongLaizhou261400,China;4.JiliUniversity,Changchun130025,China).p111114,118
Abstract:ThedissimilaritybetweenthenewLCL2typemaincircuitofsoft2switchinvertedweldingpowersourceandthebasicLCL2typeisintroduced.MathematicalmodelofnewLCL-typeoftheresonantsoft2switchinvertedweldingpowersourceisestablished,andanalyzedbyMatlabsoft2ware.Inordertotestandverifythemathematicalmodel,calculatingresultsofmathematicalmodeliscomparedwithtestingre2sults.Thearcweldingpowersourcehasnotonlyhighefficiencyofseriesresonantinthewholeloadrange,butalsobroadersoft2switchrange.Thedutycyclelossofthesecondingtransformeriseliminated.
Keywords:newLCL-type;resonantsoft2switch;invertedmaincircuit;mathematicalmodelestablishing
Predictionofangulardistortioninthickplatemulti2passweld YANGGuang2chen,XUEZhong2ming,ZHANGYan2hua(BeijingUni2versityofAeronauticsandAstronautics,Beijing100083,China).p1152118
weld.However,researchonitwasverylacking.Thepredictionofan2gulardistortioninthickmulti2passweldisanalyzed,andtheexistedem2piricalformulasaboutangulardistortionaresummarizad.Amethodfor
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