激光GMAWP复合热源焊焊缝成形的数值模拟

《激光GMAWP复合热源焊焊缝成形的数值模拟》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、山东大学博士学位论文激光+GMAW-P复合热源焊焊缝成形的数值模拟姓名：胥国祥申请学位级别：博士专业：材料加工工程指导教师：武传松;SuckJooNa20091026山东大学博十学何论文应用已建立的复合热源焊的组合式体积热源模型，对激光+GMAW-P复合热源焊的热场进行数值分析，定量研究不同电弧功率对激光+GMAW-P复合热源焊热影响区宽度和热循环参数等热场特征基础数据的影响规律，并与纯激光焊、单GMAW-P的情况进行了比较，为从冶金上揭示复合热源焊的特点奠定了基础。为更合理地选定热源分布参数，将光线追踪法与线热源小孔模

2、型相结合，较详细和准确地描述了激光束在非对称小孔内的多次反射过程以及孔壁对光能的Fresnel吸收，研发出新的小孔形状尺寸算法。将小孔尺寸与激光焊体积热源分布区域相联系，提出了基于小孔模型的激光焊体积热源模式。将此热源模式应用于激光焊和复合焊焊缝成形的数值模拟。结果表明，计算结果与实验结果吻合良好。关键词：复合热源焊，激光焊，GMAW-P，组合式体积热源，焊缝成形，温度场，小孔，数值模拟山东大学博十学侍论文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