简介：

简介：WiththemodifiedAlmenmethod,theforminganddevelopmentprocessofresidualstressinathermalsprayedcoatinghasbeenobtained.Thetestresultsidentifythattheresidualstressinacoatingisdependoncoatingmaterialproperties,techniqueandcoatingthickness.Thepaperpaysmuchattentiontothehysteresisbetweenthecoatingtemperatureandresidualstressinthecoatingorbetweentheappliedstressandthestrainofthecoating,andconfirmsthatthefactisresultedfromthe"GasFix"characterofathermalsprayedcoating.

简介：ＬｏｗｓｔｒｅｓｓｎｏｄｉｓｔｏｒｔｉｏｎｗｅｌｄｉｎｇｆｏｒａｅｒｏｓｐａｃｅｓｈｅｌｌｓｔｒｕｃｔｕｒｅｓＧＵＡＮＱｉａｏ；ＧＵＯＤｅｌｕｎａｎｄＺＨＡＮＧＣｈｏｎｇｘｉａｎ（ＢｅｉｊｉｎｇＡｅｒｏｎａｕｔｉｃａｌＭａｎｕｆａｃｔｕｒｉｎｇＴｅｃ...

简介：

简介：

简介：

简介：Thisstudydevelopedasequentialcouplingfiniteelementproceduretopredictresidualstressesofsteelpipeswithlongitudinalwela\circumferentialweldandspiralweld.Theresultsshowthattheresidualstressinheataffectedzone(HAZ)ishigherthanthatinweldforspiralweldpipe.Forthecircumferentialweldpipeandspiralweldpipe,theresidualstressininnersurfaceishigherthanthatinoutersurface.However,forthespiralweldpipe,theresidualstressininnersurfaceissmallerthanthatinoutersurface.Thehoopresidualstressofcircumferentialweldpipeishigherthanthatoflongitudinalweldpipe,whiletheaxialresidualstressofcircumferentialweldpipeissmallerthanthatoflongitudinalweldpipe.Thehoopstressesforcircumferentialweldpipeandaxialstressforlongitudinalweldpipehaveexceededtheyieldstrengthofbasemetal.Withtheincreaseofhelixangle,thehoopstressdecreaseswhiletheaxialstressincreases.Forthespiralpipe(α=30°to50°),boththehoopstressandaxialstressarerelativelysmall.Thespiralpipe(helixanglerangingfrom30°to50°)ishelpfultoreducestresscorrosioncracking(SCC)anditisrecommendedtomanufacturethesteelpipe.

简介：SYSWELDwasusedtosimulatein-serviceweldingprocessofgaspipelineofX70pipelinesteel.Weldingthermalcycle,stressanddeformationofin-serviceweldedjointwerestudied.Theresultsshowthatpeaktemperatureofcoarsegrainheat-affectedzone(CGHAZ)ofin-serviceweldingontogaspipelineisthesamewithroutinewelding,butt_(8/5),t_(8/5)andt_(8/1)decreaseatcertaindegree.Forthezonenearweldedseam,axialstressandhoopstressintheinnerpipewallarecompressivestresswhenweldingsourcepassesthroughthecross-sectionthatisstudied,butresidualaxialstressandresidualhoopstressafterweldedarealltensilestress.Transientdeformationandresidualdeformationareallconvexdeformationcomparedwiththeoriginalpipediametersize.Deformationachievesmaximumwhenweldingthermalsourcepassesthroughthecross-sectionthatisstudiedandthendecreasesduringthecoolingprocessafterwelding.

简介：

简介：MagneticBarkhausennoise(MBN)isaphenomenonofelectromagneticenergyduetothemovementofmagneticdomainwallsinsideferromagneticmaterialswhentheyarelocallymagnetizedbyanalternatingmagneticfields.AccordingtoFaraday’slawofelectromagneticinduction,thenoisecanbereceivedbythecoilattachedtothesurfaceofthematerialbeingmagnetizedandthenoisecarriesthemessageofthecharacteristicsofthematerialsuchasstresses,hardness,phasecontent,etc.Basedonthecharacteristicofthenoise,researchingabouttherelationshipbetweentheresidualstressintheweldingassemblyandthenoisearecarriedout.Furthermore,dataprocessisperformedbyRMS(RootMeanSquare)equationandPowerSpectrumanalysis.

简介：

简介：

简介：Theeffectofweldingjigontheweldingstressandbucklingdistortionofthinaluminumplatejointswassimulatedbyfiniteelementmethod(FEM).Theresultsshowthattherestraintdistanceandtheheatconductionabilityofthefixturedohaveessentialeffectsontheresidualstressanddistortion.Theresidualcompressivestressanddistortionwillbeincreasingwiththeincreaseoftherestraintdistance,whiletheresidualcompressivestressanddistortionwillbedecreasingwiththeincreaseoftheheatconductionabilityofthefixture.

简介：Thecharacteristicsoftemperatures,stressesandstrainsfieldshavebeenstudiednumericallyforatitaniumalloysheetweldedwithanimprovedgastungstenarcweldingmethod,inwhichatrailingspotheatsinkisintroducedtocontroltheweldingstressanddistortion.Theimpingingjetmodelisemployedtodescribetheintenseheattransferbetweenthecoolingmediaandthetopsurfaceoftheworkpiece.Theinfluenceofthedistancebetweenarcandheatsinkisinvestigated.Resultsshowthatthereisanidealrangeofdistance.Usingtheidealdistance,alowstressandnodistortionweldingstructurecanbederived.

简介：Whenmeasuringresidualstressofcoarse-grainaluminumalloyusingX-raydiffractionmethod,thediffractionprofileshowstwopeaksandpositionofmeasured2dwillbechanged,whichleadtoaninaccuratemeasurementresult.Hence,inthispaper,somemethodswereemployedtoimprovethemeasurementaccuracy.Duringthemeasuringprocess,differentparameters(diameterofirradiatedarea,Ψ-oscillationrangeandexposuretime)wereselectedandprofilepeakshiftmethodwasutilized.Moreover,whenthe20ofprofileswasdetermined,differentcalculationmethodswereusedtocalculatetheresidualstress.TheresultsshowthatdiameterofirradiatedareaandΨ-oscillationrangehavesignificantinfluenceonthemeasuringresult.Forstressvaluecalculateddirectlyfromthetestequipment,crosscorrelationmethodismoreaccuratethantheabsolutepeak.Furthermore,anothertwocalculationmethodsofslopewith2θ-sin~2Ψande-sin~2Ψwereusedtocalculatethestressbasedonparameters(2θ,ε)obtainedfromcrosscorrelationmethod.Itisconcludedthat20-sin~2Ψmethodcanfurtherimprovethemeasurementaccuracy.

简介：Fe3AlandCr18-Ni8steelwerebondedinvacuumandaninterfacewasformedbetweenFe3AlandCr18-Ni8steel.Stressdistributionatthediffusion-bondedinterfacewasresearchedbynumericalsimulationandfiniteelementmethod(FEM).TheresultsindicatedthatthepeakstressappearedattheinterfacenearCr18-Ni8steelside.Thisisthekeyfactortoinducecrackatthisposition.Withtheenhancementofheatingtemperature,thepeakstressatthebondedinterfaceincreases.Whenthetemperatureis1100℃,thepeakstressisupto65.9MPa,whichisbiggerthanthatat1000℃by9.4%.Inaddition,thepeakstressbecomesbiggerwiththeincreaseofthethicknessofbasemetalfrom1mmto8mm.Whilethethicknessismorethan8mm,thepeakstressvariesslightlywiththechangeofthethickness.

简介：ThedistributionsoftheaxialstressandshearstressinAl2O3-TiC/Q235diffusionbondedjointswerestudiedusingfiniteelementmethod(FEM).Theeffectofinterlayerthicknessontheaxialstressandshearstresswasalsoinvestigated.Theresultsindicatethatthegradientsoftheaxialstressandshearstressaregreatnearthejointedge.ThemaximalshearstressproducesattheinterfaceoftheAl2O3-TiCandTiinterlayer.WiththeincreaseofCuinterlayerthickness,themagnitudesoftheaxialstressandshearstressfirstdecreaseandthenincrease.Thedistributionoftheaxialstresschangesgreatlywithalittlechangeintheshearstress.TheshearfractureinitiatesattheinterfaceoftheAl2O3-TiC/TiinterlayerwithhighshearstressandthenpropagatestotheAl2O3-TiCside,whichisconsistentwiththestressFEMcalculatingresults.

简介：ThesusceptibilityofweldedjointfortheX65pipelinesteeltoH2Sstresscorrosioncracking(SCC)isinvestigated.SCCtestsonthesteelarecarriedoutintheenvironmentbasedonNACETM-01-77solutionwithsaturatedgaseousH2S.Thethresholdstressintensityfactorandcrackpropagationvelocityarecalculatedaccordingtowedge-openingloading(WOL)specimens.Thethree-dimensionalelastic-plasticfiniteelementanalysisofWOLspecimensisperformedbyusingtheFEMprogrammingpackageANSYS.Stressfieldandconcentrationofhydrogendistributionpropertyaheadofthecracktipareobtained.ThispapersurveyedthemicrostructureofweldedjointandstudiedonthemechanicalpropertiesofX65pipelinesteel.Itprovidesexperimentalbasisforstudyingstresscorrosion.Theresultsofnumericalanalysisareconsistentwithconclusionsofstresscorrosiontest.