聚能射流侵彻

NumericalStudyofShapedChargeJetFormationandPenetrationintoMulti-layerwithDifferentLinerMaterialYanlongKanga,JianweiJiangb,ShuyouWang,JianbingMen(StateKeyLaboratoryofExplosionScienceandTechnology,BeijingInstituteofTechnology,Beijing100081,China)[e-mail],[e-mail]:linermaterial;shapedcharge;titaniumalloy;numericalsimulation;Abstract.Thispaperinvestigatesthepenetrationperformanceofshapedchargeagainstmulti-layertarget.Atitaniumalloylinerofshapedchargeisproposedinordertoobtainlargeperforatedhole.Jetformationandpenetratingintomulti-layertargetwascalculatedbyhydrocodeAUTODYN.Fordifferentlinermaterialincludetitaniumalloy,mildsteelandCu,theexplosionenergyconversion,jettipvelocityandjetlength,alsothepenetrationperformancearestudied.Itisfoundthatthekineticenergyofjetislargerandtheshapeofjetispodgierwhenthelinermaterialistitaniumalloy,theperforatedholediameteronmulti-layerimproved20%comparewiththemildsteelandCuliner,thenumericalsimulationisgoodagreementtoexperimentalresults.IntroductionTheanti-runwaymunitionsisonekindofeffectivemeantoattackthehardmulti-layertargetsuchasairportrunway,whichmakesuseoffrontshapedchargetoproduceperforatedholewiththelaterfollowingwarheadandfollowingblasting.Howtomakealargeperforatedholeproducedbyfrontshapedchargeistheimportantprobleminordertoensurethelaterwarheadfollowingup.Throughchangingthelinerconeangle,linerthicknessandthetypeofexplosivechargecanimprovethediameterofperforatedholetoacertainextentbutisnotenough.Currently,research[1,2]onlinermaterialmakeitpossibletostudythelargeperforatedholeinhardtarget.AlthoughmildsteelandCulinercanmakegreaterpenetrationperformanceasthelargedepth,thelackofdiametercannotproducebigperforatedhole.Somescholarssucceedinproducingabigperforatedholebymeansofresearchonlinerwithenergeticmaterial[3].However,therearesomedifficultproblemsoncomplexmanufacturingprocesses.Thispaperpresentsanapproachofproducingabigpenetratingholeonmulti-layerbyusingtitaniumalloyliner.Thenumericalsimulationonjetformationandpenetrationintotargetbyshapedchargewhichusestitaniumalloy,mildsteelandCulinerarestudiedinAUTODYN[4].Comparingandanalyzingthedifferencesofenergyconversion,tipvilocityandlengthofjetoneachlinermaterial.Thedifferencesofperforatedholediameterisvalidatedbyexperiment.Theconclusionscanbethereferencesofanti-runwaywarheadengineeringdesigns.CalculationModelStructureModel.ThemodelofshapedchargeisatypicalstructureasshowninFig.1.Itconsistsofliner,explosivechargeandshell.ThechargediameterDkis130mm,thelengthtodiameterratioL/Dis0.8andtheshellthicknessσ1is0.025Dk.Thelinerishemisphericalshapeandvariableshellthickness.Thetoplinerthicknessσ2is0.045Dk.Thedetonationpointisatthebottomoftheexplosivecharge.Fig.2isthesimplifiedmodelofthemulti-layerstructure[5].Itconsistsofsurfaceconcrete,basesurfacepoorconcreteandbottomsurfacesoil.Thesurfacethicknessis350mmandthebasesurfacethicknessis250mm.AdvancedMaterialsResearchVols.148-149(2011)pp744-748Onlineavailablesince2010/Oct/27at©(2011)TransTechPublications,Switzerlanddoi:10.4028/(ID:138.253.100.121,UniversityofLiverpool,SydneyJonesLibrary,Liverpool,UnitedKingdom-29/08/13,08:30:00)Fig.1SchematicmodelofshapedchargeFig.2Schematicmodelofmulti-layertargetNumericalModel.Duringthejetformationandpenetrationintomulti-layerprocess,lineriscrushedbydetonationproducts,whiletheconcreteofmulti-layerissheardamaged.Allrelativematerialhasseriousdeformation.WithapurelyLagrangeorEuleralgorithmcannotdescribethewholeactionprocessaccurately.SothispaperusestheEuler-Lagrangecouplingalgorithmwhichcouplingcalculatesthejetformationandpenetrationintomulti-layerprocess.Thesimulationmodeliscreated(seeFig.3),theshapedchargewasmeshedinEulerareawhilethemulti-layermodelwascreateduseLagrangegridwithlocalrefinedmeshsize.Probleminpresentpaperisconsideredassymmetric,theshapedchargeandtargetishalfmodeled.Toshowthefreeexpandingofdetonationproducts,theflowoutboundarywasdefinedattheedgeofEulerarea.GaugeAisdefinedtogetthestressvariationofsurfaceconcretewhichpenetratedbythejet.ThestandoffSdis0.8Dk.Fig.3ThenumericalmodelinsimulationMaterialModels.Incalculationmodel,theshellofchargeis45steelwhilethelinermaterialrespectivelyaretitaniumalloy,mildsteelandCu,Johnson-cookmaterialmodelisadopttosimulatethedynamicresponseofmaterialwithlargedeformationunderhighstrainrateandtemperaturechanging.Themainstressis:)*)(1)(ln(1)((ó*mnTcBA−++=εε(1)Here,σisdynamicyieldstress,εniseffectiveplasticstrain,ε*iseffectiveplasticstrainratio,T*iscorrelationtemperature,Aisstaticyieldstress,Bisstrainhardeningcoefficient,ciscorrelationcoefficientofstrainrate,miscorrelationcoefficientoftemperature.TheexplosivechargeisComp.B,andJWLEOSwasemployedtodescribetheexplosivedetonationandenergyreleaseprocess,itassumesthedetonationfrontspreadsatconstantspeed.ThedetonationproductspressurepiseeRBeRApRRωηωηωηηη+−+−