飞机结构初步设计的快速方法研究

南京航空航天大学硕士学位论文飞机结构初步设计的快速方法研究姓名：张仲桢申请学位级别：硕士专业：飞行器设计指导教师：余雄庆20081201I12345IIABSTRACTAircraftdesigninvolvesmanydisciplines,suchasaerodynamics,structuralanalysis,lowobservableanalysis,propulsivesystem,performanceandoperationalstability,isatypicalmultidisciplinarydesignoptimization(MDO).MDOisanimportantmethodforconceptualandpreliminarydesignofinnovativeaircraft(asflying-wingtype).Thispaperfocusesonthestructuralproblemwhichisasubsystemofmultidisciplinarydesignoptimizationforaflying-wingaircraftdesign.Themaincontentincludes:1Accordingthecharactersoftheflying-wingconfigurationandstructurallayout,theparameterizedgeometricmodels,whichareusedtodescribetheflying-wingshapeandstructurecharacter,arepresented.Basedontheparameterizedgeometricmodels,theCADmodeloftheflying-wingstructurecanbeautomaticallygenerated.2Thefiniteelementmodelsforthestructureoftheflying-wingareautomaticallygeneratedbymeshingthestructuralmodel,settingtheboundarycondition,addingtheloadanddefiningtheelementproperty.3Atwo-leveloptimizationapproachforaflying-wingstructuraloptimizationproblemisproposed.Theapproachissimpleintermsofflowchartandhastheabilitytoconductboththestructurallayoutoptimizationandthestructuralsizeoptimizationsimultaneously.Theapproachisdividedintotwolevelsincludingstructurallayoutoptimizationandstructuralsizeoptimization.Thefirstlevelisthestructurallayoutoptimizationwhoseobjectiveistooptimizethelocationandthenumberoftheinnerstructuralpart,andpasstheparameterstothelevelofsizeoptimization.Thesecondlevelisthestructuralsizeoptimizationwhichcanconfirmthesizeofallstructuralpartsaccordingtothestructurallayout,andfeedbackoptimumresulttotheleveloflayoutoptimization.Afterthetwo-leveloptimization,itwillfindouttheoptimumstructureincludingboththestructurallayoutandthestructuralsize.4Thetwo-leveloptimizationapproachwasusedtooptimizethetwoflying-wingstructures(materialLY12andcompositematerialgraphite-epoxy).Theresultsindicatedthatthetwo-leveloptimizationmethodcanefficientlysolvethestructurallayoutandthestructuralsizeoptimizationproblemfortheflying-wingstructure.Thefeasibilityandefficiencyoftheapproachisverified.5Tomakethemethodmorepracticalforrealapplications,thebucklingconstraintsareaddedintheprocessofsizeoptimization.IIIThisstudyprovidesakeyelementforthemultidisciplinarydesignoptimizationoftheflying-wingunmannedaerialvehicle.Keyword:flying-wing,parametricmodeling,structuraloptimization,finiteelementmodel,structurallayout,structuralsize,two-leveloptimizationVI1.1...................................................................................12.1...................................................................................................52.2...........................................................................................62.3...................................................................................................................72.4CAD............................................................................................72.5...............................................................................................92.6.............................................................................................102.7.................................................................................................112.8.....................................................................................................122.9CATIA................................................................................................132.10...............................................................................................................142.11...............................................................................................................143.1.....................................................................................173.2.............................................................................................173.3.........................................................194.1.........................................................................................................................204.2.....................................................................................................................204.3.........................................................................................................214.4.............................................................................224.5.............................................................................................235.1.................................................................................295.2iSIGHT......................................................................................295.3.........................................................................................................295.4.........................................................................................305.5.............................................................................................305.6.............