简介:Obtainingtheimageofmoltenpoolaluminumalloy'stungsteninertgas(TIG)weldingbecomesachallengingproblemintheweldingfield.Inthispaper,abran-newopticalsensorbasedanalyzingthelightspectrumwasdesigned,andtheclearimageofthemoltenpoolduringthealuminumalloy'sweldingusingthecommonindustrialCCDcamerawasobtained.Andwiththenewalgorithmprovidedbymyself,thedesirablecharacteristicparametersofthemoltenpoolofaluminumalloy'sweldingwereobtained,anditprovidesagoodbaseforadvancedmonitorweldingquality.
简介:ColdMetalTransfer(CMT)weldingtechniqueisanewweldingtechniqueintroducedbyFroniuscompany.CMTweldingofnickel-basedalloywithstainlesssteelwascarriedoutusingCuSi3fillerwireinthispaper.Effectsofweldingparameters,includingweldingcurrent,weldingspeed,etc,onweldsurfaceappearanceweretested.MicrostructureandmechanicalpropertiesofCMTweldwerestudied.Theresultsshowthatthethicknessofinterfacereactionlayerofthenickel-basedalloyis14.3μm,whichisonly4.33%ofbasematerial.Theweldismadeupoftwophases,α-copperandiron-basedsolidsolution.Ruptureoccursinitiallyattheweldedseamneartheedgeofstainlesssteelinsheartest.ThemaximumshearstrengthoftheCuSi3weldedjointis184.9MPa.
简介:Inthispaper,anumericalinvestigationaboutthemetaltransferofGMAWisinvestigatedbasedonthephasefieldmodel.Bedifferentofmostpublishedwork,wetakethethermocapillaryeffectandmixtureenergyintotheprocessofphasetransferandinterfacechangewhichisdifferentfromvolumeoffluid(VOF)method.Wediscretizethewholemodelwithacontinuousfiniteelementmethodandwealsoapplyapenaltyformulationtothecontinuityconditionenhancingthestabilityofthepressure.MetaltransferofGMAWwithconstantandpulsecurrentiscomputedasnumericalexampleswhichagreeswellwiththedataofhigh-speedphotography.Theresultshowsthatthecomputingprocessofthephasefieldmodelisstabilityandithasahigherprecisioninpredictingthediameterofdroplet.
简介:Adual-beamelectronicspecklepatterninterferometry(ESPI)systemwasadoptedtogetspecklepatternsforthemeasurementofweldingdynamicdisplacementfields.Themathematicalmodelofthissystemwasdescribed,basedonwhichmethodsoftheESPIpatternimageprocessingwerediscussed.Graytransformationandhistogramequalizationwereusedtoenhancethecontrastofspecklepatterns.Adiscretecosineimageprocessingmethodwascarriedoutandanexponentlow-passfilterwaschosentoreducemultiplicativenoiseinspecklepatterns.Specklegrainnoisecanbeeliminatedeffectivelyaftertheseprocesses.
简介:AccordingtospecificationsforWeldingProcedureQualificationofASMEIXSectionandChinesecode,JB4708-2000,asoftwarepackageformanagingweldingdocumentshasbeenrebuilt.Consequently,thenewsoftwarepackagecanbeusedinaLimitedAreaNetwork(LAN)with4differentlevelsofauthoritiesfordifferentusers.Therefore,theweldingdocuments,includingDWPS(DesignforWeldingProcedureSpecifications),PQRs(ProcedureQualificationRecords)andWPS(WeldingProcedureSpecifications)canbesharedwithinacompany.Atthesametime,thesystemprovidesusersvariousfunctionssuchasbrowsing,copying,editing,searchingandprintingrecords,andhelpsuserstomakedecisionofwhetheranewPQRtestisnecessaryornotaccordingtothecodesaboveaswell.Furthermore,superuserscanalsobrowsethehistoryofrecordmodificationandretrievetherecordswhenneeded.
简介:Anewkindofcontrolsystemforkeyholeplasmaarcwelding(K-PAW)wasdevelopedbasedonthecomputerandtheGraphicsLanguage-LabVIEW.Itcansetandoutputtherequiredcurrentwaveformswithdesireddecreasingslopessothatthecorresponding'openingandclosing'ofkeyholecanoccurperiodically.Withthiscontrolstrategyofweldingcurrentwaveforms,theworkpieceisfullypenetratedwhilenoburn-throughoccurs.Keyholeplasmaarcweldingexperimentswereconductedtoverifythestabilityandreliabilityofthedevelopedsystem.
简介:Robot-basedremanufacturingsystemcanscanthewornpartsanddevelopthecorrespondingmodels,comparethemwiththestandardmodel,calculatethewelddeposit,implementweldingpathplanning,andrepairthewornpartswithMIGsurfacingautomatically.Thispaperinvestigatestheweldingpathplanningaftercalibrating,scanningandmodelrebuilding.Thefollowingaspectsarecontained:introducingtheplanningprinciple,selectingthesuitableweldingprocessbasedonweldingparameters(currentandspeed),calculatingweldingoverlapquantitybythesuperpositionmethod.Also,ithasbeenverifiedthatgoodweldprofilecanbeobtainedwiththeoptimizedparameters.
简介:ThelateralwaveinultrasonicTOFD(timeofflightdiffraction)imagehasatailintransittime,whichdisturbsthedetectionandevaluationofshallowwelddefect.Meanwhile,thelateralwaveandback-wallechothatactasbackgroundaddredundantdataindigitalimageprocessing.Inordertoseparatedefectwavefromlateralwaveandpreparethewayforfollowingimageprocessing,analgorithmofbackgroundremovalmethodnamedasmean-subtractionisdeveloped.Basedonthis,animprovedmethodbystatisticoftheenergydistributionintheimageisproposed.Theresultsshowthatbychoosingproperthresholdvalueaccordingtotheaxialenergydistributionoftheimage,thebackgroundcanberemovedautomaticallyandthedefectsectionbecomespredominant.Meanwhile,diffractivewaveofshallowwelddefectcanbeseparatedfromlateralwaveeffectively.
简介:Theaccuratecalculationandmeasurementofweldingtemperaturefieldisanimportantpreconditionforweldingmetallurgicalanalysisandweldingprocesscontrolling.Inthispaper,theconformaltransformationisfirstlyusedtoanalyzetheweldingtemperaturefieldoffeatheredgedcylinder.Thecenterofthecylinderischosenastheoriginofcolumncoordinatesystem,andeverypointmaybeexpressedascomplexfieldvector.Thebranchisogonalitycounterchangesthelineparallelwiththefusionlineinhalf-infinitez-planetothecircleconcentricwiththefusionlineininfinitecylinder.TheLaplaceequationandPoisson'sequationstillkeepvalidity,sothetemperaturefieldequationcanbesolved.TheconformaltransformationandequationsolutionisprocessedbyMatlabprogramlanguage.Itshowsthattheobtainedanalyticalmodelingoftemperaturefieldforfeatheredgedcylinderbasedonconformaltransformationiseffectiveandaccurate.
简介:Alotofexperimentalmethodshavebeenbroughtforthtoassessthedynamiccharacterofthearcweldingpowersource,butuptonow,thisissuehasnotbeensolvedverywell.Inthispaper,basedonthefuzzylogicreasoningmethod,adynamiccharacterassessingmodelforthearcweldingpowersourcewasestablishedandusedtoanalyzethedynamiccharacteroftheweldingpowersource.Threedifferenttypesofweldingmachinehavebeentested,andthecharacteristicinformationoftheelectricalsignalssuchasre-strikingarcvoltage,lowweldingcurrentandsoonoftheweldingprocesswereextractedaccuratelybyusingaself-developedweldingdynamicarcwaveletanalyzer.Theexperimentalresultsindicatethatthismodelcanbeusedasanewassessingmethodforthedynamiccharacterofthearcweldingpowersource.
简介:Nickel-irontypecastironelectrodesarewidelyusedforweldingQT600-3nodulariron.Nevertheless,theresearchworkhasdemonstratedthatthestrengthoftheseheterogeneousweldedjointsislow.Inthispaper,theuni-axialtensionofthejointsisstudiedbytheMoirefringemethod,andthedis-placement,strainandstressinthetotalfieldsareobtaind.Basedontheunevendistributionofstrainandstress,thereasonofcrackinitiationandpropagationisdiscussed.Throughexaminingtheappearanceofthefracturebyscanningelec-tronmicroscope,alotofsphericalsubstancesdistributedonthefracturesurfacearefound,whichmaybeanotherreasonleadingtocrackingoftheweldedjointunderthelowertensilestress.Thesenewfindingswillhelptoimprovethepropertiesofnickel-irontypecastironelectrodesandthestrengthoftheweldedjoint.
简介:AccordingtothemaintoolsofTRIZ,thetheoryofinventiveproblemsolving,anewflowchartoftheproductconceptualdesignprocesstosolvecontradictioninTRIZisproposed.InordertorealizeautonomousmovingandautomaticweldseamtrackingforweldingrobotinTailedWeldedBlanks,acreativedesignofroboticvisualtrackingsystembasedonCMOShasbeendevelopedbyusingtheflowchart.Thenewsystemisnotonlyusedtoinspecttheworkpieceaheadofaweldingtorchandmeasurethejointorientationandlateraldeviationcausedbycurvatureordiscontinuityinthejointpart,butalsotorecordandmeasuretheimagesizeoftheweldpool.Moreover,thehardwareandsoftwarecomponentsarediscussedinbrief.