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1、山東大學(xué)博士學(xué)位論文激光+GMAW-P復(fù)合熱源焊焊縫成形的數(shù)值模擬姓名:胥國祥申請學(xué)位級別:博士專業(yè):材料加工工程指導(dǎo)教師:武傳松;SuckJooNa20091026山東大學(xué)博十學(xué)何論文應(yīng)用已建立的復(fù)合熱源焊的組合式體積熱源模型,對激光+GMAW-P復(fù)合熱源焊的熱場進(jìn)行數(shù)值分析,定量研究不同電弧功率對激光+GMAW-P復(fù)合熱源焊熱影響區(qū)寬度和熱循環(huán)參數(shù)等熱場特征基礎(chǔ)數(shù)據(jù)的影響規(guī)律,并與純激光焊、單GMAW-P的情況進(jìn)行了比較,為從冶金上揭示復(fù)合熱源焊的特點(diǎn)奠定了基礎(chǔ)。為更合理地選定熱源分布參數(shù),將光線追蹤法與線熱源小孔模
2、型相結(jié)合,較詳細(xì)和準(zhǔn)確地描述了激光束在非對稱小孔內(nèi)的多次反射過程以及孔壁對光能的Fresnel吸收,研發(fā)出新的小孔形狀尺寸算法。將小孔尺寸與激光焊體積熱源分布區(qū)域相聯(lián)系,提出了基于小孔模型的激光焊體積熱源模式。將此熱源模式應(yīng)用于激光焊和復(fù)合焊焊縫成形的數(shù)值模擬。結(jié)果表明,計算結(jié)果與實(shí)驗(yàn)結(jié)果吻合良好。關(guān)鍵詞:復(fù)合熱源焊,激光焊,GMAW-P,組合式體積熱源,焊縫成形,溫度場,小孔,數(shù)值模擬山東大學(xué)博十學(xué)侍論文Numericalsimulationofweldformationinlaser+GMAW-Phybridweld
3、ingABSTRACTAsanew-stylehigh—qualityandhigh—efficiencyjoiningtechnique,laser+pulsedGMAW(GMAW-P)hybridweldingcombinesthebenefitsofbothlaserbeamwelding(LBW)andGMAW-Pandhasthesynergisticeffectof“1+1>2”.Thus,itisofsignificantpotentialinindustrialapplications.Uptonow,h
4、owever,mostofstudiesonhybridweldinghavejustfocusedontheparameteroptimizationbyexperiments,andthereisalackoffundamentalinvestigationsinvolvingitsphy’sicalmechanism.Sincehybridweldinginvolvesmoreweldingparameterscomparedwithsingleweldingprocess,itsphysicalprocessis
5、morecomplicated.So,determiningtheprocessparametersonlybyexperimentsrequiresvastamountsofmanpowerandmaterialresources,therebyhinderingitsfurtherspreading.Inthisstudy,usingthenumericalsimulationtechnique,theweldformationandthermalfieldcharacteristicsinlaser+GMAW-Ph
6、ybridweldingareinvestigatedthroughdevelopingtheadaptiveheatsourcemodel,thusprovidingthetheoreticalbasisandreferencedataforstudyofhemtransfermechanismandweldingparameteroptimization,whichisofgreattheoreticalsignificanceandpracticalvalue.Afterconsideringthegeometry
7、characteristicsofweldcrosssectionandanalyzingthethermalactionfea:turesindeep-penetrationlaserwelding,fouradaptiveandsuitablerotaryvolumetricheatsourcesfordeep—penetrationlaserweldingaredeveloped,i.e.powerpeakdensityexponentiallyincreasing-conicheatsource,powerpea
8、l(densitylinearlyincreasing-logarithmiccurverotatedbodyheatsource,powerpeakdensitylinearlyincreasing—paraboliccurverotatedbodyheatsourceandpowerpeakdensityhype