無網(wǎng)格法及液體射流高速碰撞與侵徹模擬.pdf

1、浙江大學(xué)航空航天學(xué)院博士學(xué)位論文無網(wǎng)格法及液體射流高速碰撞與侵徹模擬姓名：馬利申請學(xué)位級別：博士專業(yè)：固體力學(xué)指導(dǎo)教師：郭乙木20070601浙江大學(xué)博：學(xué)位論文AbstractTothehighspeedimpactproblem，fluid—solidinteraction，dynamicallhctureandlargedeformationproblems，thelargedeformationwillinducetothela

2、rgedistortionofthefiniteelementmeshandmadethereductionofprecisionf咖theterminationofcomputationbysingularity；ontheotherhand，thecomputationaltimestepofFEAdependedontheminimumsizeofmesh。thedistortionofmeshmadethetimestepbec

3、ameverysmalI，whichmadethewholecalculationtimeextendedandtheaccumulatedelrorincrescontAIsothereconstructionofmeshwillconsumelargecomputationcostindealingwithdynamicalfractureproblemToovercomethesedifncultiesofFEAthemeshfr

4、eemethodwasdevelopedinrecenttwodecadesandbecamethehompotofcomputationalphysicsandmechanicsByseriesparticleswithoutanymeshstructurethemeshfreemethod啪avoidabovedifneultiesofFEAThemainworkofthispaperfocusedontheflgorithmand

5、applicationofthemeshfreemethod，TheprocessofmeshfreemethodincludedthecomputationofshapefunctionboundaryconditionsandintegralschemeandsoonTheboundarycharacteristicsofKelfieIfunctionMLSmethodandRKPMwascomparedandthe“virtual

6、particlemethod”waspresentedtoireprovetheboundaryaberrationofSPHUsuallytheshapefunetionofmeshfreemethodwash’timerpolationfunction，whichwasallobstacletoapplytheessentialboundaryconditionsSothedit℃ctmethod1agrangemultiplier

7、methodandpointinterpolationmethodweleusedtodealwiththeboundaryconditionsandtheresultindicatedtheadvantageofLagrangemultipliermethodThecomputationalexampleofcantileverilluminatedtheresultsensitivityt0thesmoothinglengthofs

8、upportradiuswhenusesinglepointintegralschemeinEFGmethodhoweverincreasethenumberofintegralpointscandecreasethesensitivityandireprovethecalculationprecisionOntheaspectofapplicationofmeshfreemethodtheLagrangeFEAmethodALEmet

9、hodandSPHmethodwasusedtosimulatetheprocessofwaterjetimpaetwiththerigidsurfaceandthecomparisonofresultprovedt11emeritofSPHfromtheDointofprecisionandcostAIsotheAluminumfluidietimpactwimthe^gidsurfacewascomputedinwhichthevo

10、ronoieellwasadloptedtoassigntheinitiallocationandmassofparticlesandthevariablesmoothingIongthwasconsideredTheprocessofAluminumfluidietstrikedtherigidsurfaceandenteredintothestableflowwasanalyzed；theresultindicatedtheprop

11、ertiesofwavepropagationanddispersionAtthesametime，onthebaseoffluidietimpactwithrigidsurface，thecoupledSPHandFEAmethodwaspresentedtosimulatetheimpactandpenetrationofwaterjetwitbplastictargetTheeffectofhigllstrainrateandra

12、tedependenteffectoftargetmaterialwereconsideredandtheJohnsonCookmodelwasusedinnumericaIsimulation，BytIlesimulationresultofhalfinfinitetargetandmiddlethicknesstargetthelinearrelationbetweenjetvelocityandpenetrationdepthan

13、dradiuswasacquiredwhichwasconsistentwitl，theexperimentaldataofJitemtoresandtheresultalsoshowedtheprocessoffracturewasdevelopedwithaIimitedspeedwhichwasaprocesswithenergyaccumulationandexhibitedlageffectunderhJ曲strainrate

14、loadThemultiscaletheorycombinedRKPMandwaveletanalysiswasintreducedinthelastpartofthepaperthemultiscaleanalysiswaslinkedwithshapefunctiontoconstructthemultiscaleformulationofdisplacementandstressfieldAIsotheadaptivealgori

15、thmofmultiscaleRKPMmethodandthetheoryandapplicationofwaveletfinitcelementwereintroducedKeywords：meshfreemethodsmoothingparticlebydradynamicsreproducingkernelpartickmethodfmiteelementanalysisfluidjethigh—velocityimpactpen