简介:ThefatiguebehaviorofweldedstructuresiscurrentlydeterminedbymeansofrecommendationsdefinedintermsofS-Ncurvecorrespondingtothedetailclassesofweldedjointswithouttakingaccountoftheactualgeometryoftheweld.AnewfatiguestrengthassessmentmethodbasedonDangVanmultiaxialfatiguelimitcriterionwasintroduced,whichisnamedthelocalapproachandpresentedbyInstitutdeSoudurerecently.Thelocalapproachhasadvantagesintakingweldingresidualstressesandthegeometryoftheweldtoeandweldrootintoconsideration.TheapplicationofthelocalapproachtothefatiguestrengthassessmentoflowcarbonsteelQ235Bweldedjointswasstudied.ThefatiguetestsandfiniteelementanalysisresultsshowthatthelocalapproachparametersrecommendedbyInstitutdeSoudurewereincorrectlyforlowcarbonsteelQ235Bweldedjoints.Withaluminumalloyweldedjointsbeingusedwidely,theparametersofthelocalapproachusedforaluminumalloyweldedjointswereobtainedandverifiedonbasesofthefatiguetestsandfiniteelementanalysis.
简介:Imagesensorhasbeenoneofthekeytechnologiesinintellectualizedroboticswelding.Edgedetectionplaysanimportantrolewhenthevisiontechnologyisappliedinintellectualizedweldingroboticstechnologies.Thereareallkindsofnoisesinweldingenvironment.Thealgorithmsincommonusecannotbeappliedtotherecognitionofweldingenvironmentdirectly.Theedgeofimagescanbefellintofourtypes.Theweldimagesareclassifiedbythecharacteristicofweldingenvironmentinthispaper.Thispaperanalyzessomealgorithmsofedgedetectionaccordingtothecharacterofweldingimage,somerelativeadvantagesanddisadvantagesarepointedoutwhenthesealgorithmsareusedinthisfield,andsomesuggestionsaregiven.Thefeatureextractionofweldseamandweldpoolaretwotypicalproblemsintherealizationofintellectualizedwelding.Theiredgefeaturesareextractedandtheresultsshowtheapplicabilityofdifferentedgedetectors.Thetradeoffbetweenprecisionandcalculatedtimeisalsoconsideredfordifferentapplication.
简介:Thetenacityofheat-affectedzone(HAZ)willdeclineandthesizeofgrainswillincrease,becauseoftheoverheatingonHAZwhensubmergedarcwelding(SAW)isusedtothickplatewithhighheatinput.TheshapingwillworsenwhenSAWisusedtothinplatewithhighcurrentathighspeed.AnewSAWtechnology,thepulseddirectcurrent(DC)automaticSAW,willbeputforwardinthispaperinordertoovercometheaboveshortcomings.Andapulsedcontrollerwithmicro-controllerunit(MCU)asthecore,nixietube(NT)andkeyboardastheman-machineconversationinterfaceisdeveloped.Themainfunctionsofthepulsedcontrollerincludetheoutputofpulsedweldingcurrentandtheworkingwithtwinwire.Theresearchhaswidelyprospectsinapplicationwithsignificantmeaningsintheoryandpracticalengineering.
简介:AnewtypeofDZ9000EOxygenGaseousHVOFsystem(GHVOF)isdevelopedwhichcanreducethecostofcoatingsandincreasethein-situremovabilitytoadaptvariousworkingconditions.Thewholesystemiseconomical,whichenablesthesystemtomeettherequirementofsprayingmediumorlowcostHighVelocityOxy-Fuel(HVOF)coatingsformediumandsmalljobshops.ThedepositedcermetscoatingsbytheDZ9000EsystemhavegoodperformancewithaveragemicrohardnessHV0.2ofmorethan1000andthebondstrengthbetweencoatingandsubstrateofgreaterthan50MPa.
简介:Aimingattheweldingconditionofspacecomplexseamisuncertainandtheintelligenceofweldingrobotisunideal,atwo-wheeledmobilerobotisdeveloped.Itnotonlyhasthecapacityofautonomousdecisionandavoidingobstacles,butalsocanflexiblymoveandstronglyadaptvariableenvironment.Thecompositionoftheweldingrobotisdescribedandthedynamicmodelisestablished.Thefeasiblecontrolstrategyandcontrolalgorithmisputforward.Thesimulationexperimentsofrealworldareconducted,theresultsaresatisfying.
简介:MagneticBarkhausennoise(MBN)isaphenomenonofelectromagneticenergyduetothemovementofmagneticdomainwallsinsideferromagneticmaterialswhentheyarelocallymagnetizedbyanalternatingmagneticfields.AccordingtoFaraday’slawofelectromagneticinduction,thenoisecanbereceivedbythecoilattachedtothesurfaceofthematerialbeingmagnetizedandthenoisecarriesthemessageofthecharacteristicsofthematerialsuchasstresses,hardness,phasecontent,etc.Basedonthecharacteristicofthenoise,researchingabouttherelationshipbetweentheresidualstressintheweldingassemblyandthenoisearecarriedout.Furthermore,dataprocessisperformedbyRMS(RootMeanSquare)equationandPowerSpectrumanalysis.
简介:Inordertosolvethehigh-priceandshort-lifetimeproblemsofthecutterofagriculturalmachinery,andimprovethewearresistanceofthecutter,theTiCN/FemetalceramiccompositecoatingwaspreparedonthesubstrateofQ235steelbyreactionnitrogenarccladdingtechnique.ThemixturepowderoftitaniumandgraphitewaspreplacedontheQ235steelsurfaceafterintensivemixingbyplanetaryballmillandgluingwithstarchbinder.Themicrostructureandphaseofthecoatings,interfacebehaviorbetweencoatingsandthesubstratewereinvestigatedbyscanningelectronicmicroscopeandX-raydiffractometer.Themicro-hardnessdistributionofthecoatingsectionwastestedbymicro-hardnesstester.Frictioncoefficientandwearweightlossweremeasuredbyabrasionmachine.Wearingsurfacemorphologywasinvestigatedbyscanningelectronicmicroscope.TheresultsshowthatanexcellentbondingbetweenthecoatingsandtheQ235steelsubstrateisensuredbythestrongmetallurgicalinterfaceandphaseofthecoatings.ThecoatingsaremainlycomposedofTiCN.Thehighestmicrohardnessofthecoatingsreaches1089HVO.2,whilethemicro-hardnessofQ235steelsubstrateisonlyabout286HVO.2.Theanti-abrasivetestresultsshowthatthewearresistanceofthecladdingcoatingisbetterthanthatofquenchedandtempered65Mnsteelwhichisoftenusedascutterofagriculturalmachinery.ThefieldtestresultsshowthattheTiCN/Femetalceramiccompositecoatingpreparedbyreactionnitrogenarccladdingisfeasibletothemanufactureandremanufactureofthecutterofagriculturalmachinery.
简介:Thedigitalizationofarcweldingpowersourcemainlydependsonthedigitalizationofarcweldinginverter,sothatmaincircuitandcontrollingsystemcangivefullplaytoadvantages.DigitalswitchingcontrolmakesmaincircuitdigitalandDSPand/orMCUmakescontrollingsystem,digital.SoIGBTdrivingcircuit,asatieofmaincircuitandcontrollingsystem,shouldalsobegotdigitalized.Thus,adigitaldrivingcircuitbasedonoptocouplerdeviceHCPL-316Jisprovided.Sometestingexperimentsweredone.Afterdrivingtesting,thedrivingcircuitcertificatesthatdrivingwaveformssatisfytherequirementsofarcweldingpowersourceandthedrivingcircuitisreasonablyandsimplydesigned.Andthedrivingcircuithashighcontrollingprecisionandreliability.No-load-voltagetestingandweldingexternalcharacteristictestingprovethatthedrivingcircuitcanbeappliedinarcweldingpowersource.
简介:AnewsimulationmodelofCO2short-circuitingtransferweldingmaybeemployedtodevelopanewpatternofweldingmachineandtopredictweldingprocessparameterstoobtaintheoptimumweldingtechnologyproperties.Inthispaper,anewsimulatingmodelisdevelopedaccordingtotheAWP(adaptingweldingphysicsprocess)waveformcontrolmethod.Goodagreementisshownbetweenthepredictedandexperimentallydeterminedresults.ThemodelwillmakeanimportantpromotioninthedevelopmentofCO2arcweldingtechnique.
简介:Nuggetsplashduringaluminumalloysspotweldinghasadetrimentaleffectonweldnuggetintegrity,strengthanddurabilityoftheweldedjoints.Thisinvestigationisperformedtoidentifynuggetsplashfromvoltagesignalsbecausetheseareeasilyaccessibleon-line.Inthepresentwork,weproposeanovelmethodbasedonthewaveletpackettransformanditsenergyspectrumforpatternrecognitionofsplashsignal.Theresultdemonstratesthatthisnovelmethodismoreaccuracyandausefulwayofmonitoringthespotweldingquality.