焊接薄板結(jié)構(gòu)變形數(shù)值模擬研究.pdf

1、天津大學(xué)博士學(xué)位論文焊接薄板結(jié)構(gòu)變形數(shù)值模擬研究姓名：閻俊霞申請學(xué)位級別：博士專業(yè)：材料加工指導(dǎo)教師：霍立興1999.2.1ABSTRACTThewelding—induceddistortiongenerallyexistsintheengineeringfieldandhavebeentakenmorcattentiontoitThispaperpresentsananalysistechniquecombinedwithfinit

2、eelementsimulationandplatestabilitytheoryforpredictingweldinginduceddistortion，andthemechanismofbucklingformationandinfluencefactorsonbucklingdistortionduringweldingthinplatedstructureswereinvestigatedThispaperhasbeendon

3、einfollowingaspects：1Thestudyontheweldinginducedbucklingdistortionathomeandabroadissummarizedinanallroundway，andthedevelopeddirectionofnumericalsimulationtechniqueforpredictingwelding—inducedbucklingdistortioninafewyears

4、isindicated2Themechanismofbucklingformationofweldingthinplatehasbeertanalyzedanditisdemonstratedthattheessentialcauseistheshrinkageofweldzonealongthelongitudinaldirectionwhichresultedincompressiveplasticdeformationaround

5、theweldBoundaryconditions，geometryofthestructure。initialimperfectionsandweldingheatinputetehaveastronginfluenceonthefinalresidualstressesandstateofdistortionTheinteractionbetweentheweldzoneandtheoverallmaybelargeenoughto

6、dominatethefinaldistortionandresidualstressstates，bothinthestructureandinthelocalweldzoneSothepostbucklingbehavioronlyCarlbepredictedthroughthenonlinearlargedeflectionsolutionofplate3Wimthecharacterofthethickmuchlessthan

7、theotherdirectionofthinplate、anumericalanalysistechniqueforpredictingwelding—inducedbucklingdistortionoflargethinplatestructurehasbeenpresentedThetechniquecombinestwodimensionalthermalelasticplasticsimulations、Ⅳi吐1threed

8、imensionalstructuralbucklinganalysesinadecoupledapproachThepredictedresidualstressfromatwo—dimensionalweldingsimulationisusedtodeterminetheloadingforthethreedimensionalplatestructuralanalysesBucklingdistortionmodelsofman