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ABSTRACTBOOKTABLEOFCONTENTS

UNDEXNUMERICALMETHODS&APPLICATIONSIApplicationofanRKDGDGFMw/ALEMethodtoModelUnderwaterExplosions.......................................................1

ADirectGhostFluidMethod(DGFM)forModelingExplosiveGasandWaterFlows...................................................1

TheInfluenceofVaporBubblesIntheMitigationofUnderwaterExplosionStructuralLoading.................................1

DynamicResponseofaCompositePropellerBladeSubjectedtoShockandBubblePressureLoading.......................2

StudyfortheCloseProximityUnderwaterExplosionProblemUsingSimplifiedShipModel.......................................2

ShockResponseAnalysis&EvaluationforOnBoardEquipmentAccordingtoApproachMethodologyBasedontheDesignRegulation..........................................................................................................................................................2

STRUCTURALRESPONSETOBLASTLOADING

Modelingconcreteerosionstrainforblastresistantdesign.........................................................................................3

Dynamicanalysisonmembraneeffectofonewaysupportedstructurestoresisttriangularpressureload..............3

LimitationsandConsequencesofFragmentProtectionforNearFieldAirblastMeasurements..................................3

InnovativeBlastResistantDesignofSteelStudWallSystemsAccountingforCompositeBendingandControlledHingeFormation............................................................................................................................................................4

ConnectionDesignofSteelMembersSubjectedtoBlastLoading................................................................................4

DEDICATEDSESSION:UNDERWATEREXPLOSIONLOADING

AMethodforFittingWaterEOSParametersforUnderwaterExplosionSimulations..................................................5

DeterminationofSeaBottomPropertiesUsingUnderwaterExplosionPressureData................................................5

DYSMASSimulationoftheUnderwaterExplosionShockWaveLoadingfromaLargeChargeontheSeaBottom.....5

AnImprovedPentoliteJWLEquationofStateforUNDEXShockandBubbleSimulations...........................................6

ValidationExamplesUsingtheImprovedPentoliteEOS...............................................................................................6

INSTRUMENTATIONMETHODS

Characterizationofdampedaccelerometersusingpulseshapingtechniquesforhigherenergyshockinputs...........6

Miniaturizedhighgshocktriaxialaccelerometers........................................................................................................6

LaboratoryPreScreeningMethodforPreDetonationMaterialsAgainstPlungerTypeFuzedMortarsUsinganInstrumentedInertFuze................................................................................................................................................7

AIRBLASTDATA&ANALYSIS

GuidetoNuclearAirblastRecords:AReportSummary................................................................................................7

SalvagingAirblastImpulseDatafromShieldedGauges................................................................................................8

MULTIAXISVIBRATION

OnControlling6DOFElectrodynamicTables................................................................................................................8

MultiaxisExcitationMoreRealisticVibrationTesting.................................................................................................9

ContemporaryMultiAxisTestSystems:Applications,PerformanceandLimitations...................................................9

BringingTrueBroadbandFieldVibrationEnvironmentsintotheLab...........................................................................9

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ComparativeResultsofSingleAxisVibrationvs.MultiAxis.......................................................................................10

StressBasedComparisonsbetweenSingle&MultipleDegreeofFreedomVibration...............................................10

MODELING&SIMULATIONOFUNDERWATERSHOCK

AutomatedShipShockM&SSoftwareToolIntegration;TheNewCommonStructuralModel(CSM)GUI:RapidEarlyStageDesignTool........................................................................................................................................................10

EffectofaBubblyLayeronanIncomingPressureWave............................................................................................11

Parameterizationofthepressurewaveemittedbyhydrostaticimplosionofsubmergedcylinders..........................11

Useofaneuralnetforresponsesurfacebasedpredictionofthepressurewaveemittedbyhydrostaticimplosionofsubmergedcylinders....................................................................................................................................................11

BLASTMEASUREMENT&ANALYSIS

PredictionofLandmineBlastEffectswithCONWEPandSPHinLSDYNA..................................................................12

Modelingdetonationstoinformblastresistantdesignofbuildings..........................................................................12

ImplicationsofExplosivelyAcceleratingThinFlyerPlatesinTransientRegimesofExplosiveSystems......................12

ExperimentalResistanceFunctionDevelopmentUsingLoadTreeTestingforIncorporationintoSingleDegreeOfFreedomDynamicBlastAnalyses................................................................................................................................13

BlastOverPressureEnvironmentsforEvaluatingSoldierProtectiveEquipment.......................................................13

AComparativeAnalysisofAirblastLoadPredictionModels.......................................................................................14

DEDICATEDSESSION:UNDERWATEREXPLOSIONBUBBLESIMULATIONS

AssessmentofMultiCycleUnderwaterExplosionBubbleSimulationCapabilitiesinDYSMAS..................................14

ValidationofDYSMASforCloseInShockandBubbleJetTestAgainsttheExTurkuFastAttachCraft......................14

DYSMASSimulationofUnderkeelBubbleJetAttack..................................................................................................14

AccurateandEfficientPhysicsBasedSoftwaretoModelAirGuns............................................................................14

ProcessforAcceptabilityofShockIsolatedDeckModule(IDM)ShockEnvironmentfortheInstallationofCommercialOfftheShelf(COTS)EquipmentonSubmarines.....................................................................................15

StudiesinSmallChargeUNDEXShotSelectionforSubmarineAnalyses....................................................................15

CREWINJURYSTUDIES

OverviewoftheUNDEXInducedInjuryTestSeries....................................................................................................16

UNDEXInducedInjuryTestSeries:EvaluationofAnthropomorphicTestDevice.......................................................16

AnAlgorithmforPredictingCrewInjuries/CasualtiesDuetoAIREXLoading.............................................................16

ControllingBlastEffectsUsingNovelCombinationsofPolymers,MeshesandHighlyVoidedFiberReinforcedComposites..................................................................................................................................................................16

OutofPositionLoadingResponseoftheHIII&MILLXLowerLegstoSimulatedBlastEffects.................................16

3DDynamicFiniteElementAnalysisofaWeldedandBoltedAppliqueConnectionDetailforGroundVehicleUnderbellyBlastProtection.........................................................................................................................................17

ISOLATION&DAMPING

VersatileDesignofInternallyIsolatedEnclosures.......................................................................................................17

TunedElastomerVibrationIsolatorfortheReductionofRandomVibration.............................................................18

SimulationAlgorithmforOrthogonallyCoupledBehaviorofIsolators.......................................................................18

DescribingtheShockResponseofanIsolatedEnclosureanditsInternalComponentsusingModalAnalysis..........18

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UNDEXNUMERICALMETHODS&APPLICATIONSII

OnTheShockEnvironmentInsideShipsTanks...........................................................................................................19

ComparisonofUNDEXResponseUtilizingDifferentMethodologies..........................................................................19

NewnumericaltransientandspectralmethodstomodelnavalequipmentsagainstUndexLoading......................19

ShockResponseSpectrumComputationforNonlinearStructuresusinganExplicitDynamicsFEACode.................20

BALLISTICS

QualificationTestingforBallisticShockEnvironments...............................................................................................20

Simulationofballisticimpactsofaluminumplateswithogivenosesteelprojectiles................................................21

Part1:CTHLagrangianCapabilities.............................................................................................................................21

Part2:CTHLagrangianCapabilities.............................................................................................................................22

AccelerationProfileofAnExplosivelyDrivenFlatMetallicFlyerDuringProjection...................................................22

UNDEXMODELING&TESTING

ImplosionAtSeaExperiments:ComparisonofPreTestPredictionswithTestData..................................................22

ANewPlatformforWaterBackedUNDEXTestingofCompositePanels...................................................................23

MassShockQualificationofCableHangers................................................................................................................23

CostReductionMeasuresforLocalCableHangerInstallation....................................................................................23

DEDICATEDSESSION:HARDTARGETDEFEATI

OverviewofHardTargetDefeatProjectAgreement,Phase1....................................................................................24

OverviewofHardTargetDefeatProjectAgreement,Phase2....................................................................................24

UseofHighSpeedVideoforDataAcquisitioninaHostileEnvironment....................................................................24

EquipmentFragility/DamagePhenomenologywithRespecttoHardTargetDefeatTesting.....................................24

DEDICATEDSESSION:UNDERSTANDINGSECURITYOFCRITICALINFRASTRUCTURE

ImportanceofInfrastructureSecuritytoModernSociety..........................................................................................25

AgingTransportationInfrastructure&ItsImpactonNationalSecurity......................................................................25

TheEvolutionofCriticalInfrastructureSecurityCaseStudies.................................................................................25

SHOCKANDVIBRATIONTESTINGMEASUREMENTS&QUALIFICATIONTESTING

DesignandTestResultsofaMultifrequencyReedGagetoAssessDamagePotentialofShockLoading...................26

MeasuringUnderwaterExplosions:TransducersandTheirApplication.....................................................................26

ShockExtensionMethodsResourcesforManufacturers............................................................................................26

ShockandVibrationQualificationDatabases..............................................................................................................26

BalancingaFigure15FixtureontheMediumWeightShockMachineWithoutBallastWeightwithSupportingAnalysis........................................................................................................................................................................27

MECHANICALSHOCKTESTING

SmartHydraulicLandingGear.....................................................................................................................................27

ImpactReductionTo120mmMortarTESTBASEIMPACTPIT@WatervlietFederalArsenalusingKELLETTMATERIAL.....................................................................................................................................................................................27

ExperimentalevaluationofHelicalElectromagneticLaunchersforElectronicallyProgrammableShockPulses.......28

StrainGaugesorLaserVibrometer?............................................................................................................................28

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ReferenceStandardsforCalibrationofShockAccelerometers...................................................................................28

TrundlingShocksDevelopmentofSemiAutomaticProcessesforAnalysisandTestSpecification.........................29

NUMERICAL&TESTAPPLICATIONSFORBLASTANDBALLISTICS

NumericalSimulationofISOContainersSubjectedtoInternalExplosions.................................................................29

NumericalSimulationofExplosivesBuriedinSoil.......................................................................................................30

NovelKineticDefeatApproachesforOverheadProtectionSystemsEmployingConstructionGradeMaterials.......30

ModelingofHEFillBehaviorDuringImpactComparingLagrangian,EulerianandSPHMethodologies....................30

AnalysisandTestingofanInnovativeWallDesignforResistancetoBlastEffectsfromaConfinedExplosion..........31

AssigningOverPressureandFragmentImpacttoanInteriorLagrangianBlastSimulation.......................................31

DEDICATEDSESSION:HARDTARGETDEFEATII

VulnerabilityofComputerEquipmentandNetworkstoBlastEnvironments,DistributionD+..................................31

ComparisonofMEVAPredictionstoTestData...........................................................................................................32

ResponseofDesktopComputerWorkStationstoBlastPressureLoadsProducedByExplosiveDetonations..........32

IterativeModelDevelopmentforComplexBlastEnvironments(DistributionD).......................................................32

SecondaryDebrisLoadingonBunkerWallsfromInternalExplosions........................................................................32

DEDICATEDSESSION:TRENDSINCRITICALINFRASTRUCTURE

SustainabilityArchitectsOverview.............................................................................................................................33

IntegrationofSustainability&BuildingSecurity.........................................................................................................33

StructuralHealthMonitoringforBridgeApplications.................................................................................................33

StructuralHealthMonitoringSystemsforRapid,PostDisasterAssessmentofBuildings..........................................33

StructuresManagementinMultihazardEnvironment................................................................................................33

WIMData,RiskManagement,&BridgeSecurity........................................................................................................34

DEDICATEDSESSION:NSRPMODELINGANDSIMULATIONPROJECT/NSRPFOUNDATIONMODELING&ANALYSISI

NationalShipbuildingResearchProgram....................................................................................................................34

NSRPModeling&SimulationProject...........................................................................................................................34

ShipStructureOptimizationStudies............................................................................................................................34

EfficientGenerationofAnalysisModelsforShipStructures.......................................................................................35

AutomationofModelingthe3DWeldingProcessesforDistortionandResidualStresses.......................................35

StreamliningtheSimulationProcessFlowusingCollaborativeSimulationDataManagement..................................35

MECHANICALSHOCKMODELING&ANALYSIS

ModelingofOrdnanceInducedPyrotechnicShockTesting........................................................................................36

TimeDomainAnalysisandEmpiricalModelingofShockResponses..........................................................................37

Modeling&DevelopmentofLowFrequencyMechanicalFilterAccelerometerMounting........................................37

ImplementationofEquationofStateforDrySandinAutodyn..................................................................................37

ModificationofShockIsolationMountPredictions&LoadingEstimates(SIMPLE)ProgramforMultipleInterlinkedEnclosureAnalysis.......................................................................................................................................................38

DevelopmentofLandscapeVehicularAntiramSystemsthroughComputationalandExperimentalMethods........38

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SHOCK&VIBRATIONTESTING

AnExampleofConservatisminMILSTD167Testing.................................................................................................39

ShieldTMMountDynamicLoadDeflectionCharacerization,MILSTD167VibrationResults,&MILS901DResults.....................................................................................................................................................................................39

HowTestSetupAffectsLargeEquipmentVibrationResults.......................................................................................39

Design,AnalysisandTestingoftheM109A6PaladinPIMElectricServoAmplifierIsolationSystem.........................39

MediumWeightShockMachine(MWSM)EquipmentKillCriteria:TestDesign,Setup,andExecution....................40

DEDICATEDSESSION:SYSTEM&PAYLOADRESPONSETOSHOCKENVIRONMENTSI

ALinearizedRepresentationofPenetratorSimulantDynamicswithaCorrelatedFEModel.....................................40

EmbeddedInstrumentationinPenetrationApplications............................................................................................40

InSituDynamicsofElectronicsBoards&ComponentsUnderShock.........................................................................40

ModelingandSimulationofPottedElectronicswithDifferentSolderMaterials.......................................................41

EnergyPropagationThroughNormal&ThreadedInterfaces.....................................................................................41

DEDICATEDSESSION:CRITICALINFRASTRUCTURETOOLS&PROCESSES

ResiliencyandInfrastructureSecurity.........................................................................................................................41

PerformanceBasedDesign(PBD):BuildingSecurity...................................................................................................41

TheBuildingSecurityRatingSystemOfAei.................................................................................................................42

IntegratedRapidVisualScreening(IRVS)....................................................................................................................42

OwnersPerformanceRequirements(OPR)forBuildings............................................................................................42

EvaluatingtheEffectsofExplosiveDevicesinUrbanStreetscapes.............................................................................42

DEDICATEDSESSION:NSRPMODELINGANDSIMULATIONPROJECT/NSRPFOUNDATIONMODELING&ANALYSISII

EnhancingtheShockAnalysisProcessbyIncorporatingAutomation,Optimization,&SensitivityStudies...............43

EfficientModelingofFoundationsPart1(AutomationofGeometryIdealizationforShockModeling,DDAMAnalysis).......................................................................................................................................................................43

EfficientModelingofFoundationsPart2(AutomationofGeometryIdealizationforShockModeling,DDAMAnalysis).......................................................................................................................................................................44

SemiAutomationoftheFoundationAnalysisProcess................................................................................................44

OptimizationDrivenDesignProcessforFoundations.................................................................................................45

AStudyofVariousFoundationProcesses...................................................................................................................45

VIBRATIONTESTING

Continuous/DiscreteSpectraforThreeDegreeofFreedomVibrationEnvironments...............................................46

HullVibrationReductiononaFisheriesResearchVesselusingActiveControl(Parts1&2)......................................46

WorkingTowardsOptimumLifeforAircraftDefensiveAids.......................................................................................46

UNDEXANALYSIS&MODELING

MultiScaleModelingOfStructuralDamageDueToWeaponsEffectsLoading.........................................................47

EvaluationofCompositeMaterialDamageModelsinaWaterBackedUNDEXEnvironment...................................47

InvestigationoftheFundamentalDriversinImplosionDynamics..............................................................................48

AnImprovedFluidStructureInteractionSoftwareCodeforSimulatingImplosion....................................................48

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PredictionofDynamicNonlinearBehaviorofaShockIsolatedDeckModuleComposedofTStiffenedPlate..........48

DamagePredictionOfAWeaponsElevatorDoorOnTheFloatingShockPlatformUsingNonlinearTransientAnalysis........................................................................................................................................................................48

DEDICATEDSESSION:SYSTEMANDPAYLOADRESPONSETOSHOCKENVIRONMENTSII

HighFrequencyStructuralExcitation:ImplementinganAcousticSource..................................................................49

HighFidelityForceLocalizationinBeamStructures....................................................................................................49

BlastSimulatorTestingforHighGShockEnvironmentCharacterization...................................................................49

PracticalDSPforShockEnvironments.........................................................................................................................49

Calibrating&EvaluatingPerformanceofCOTSPiezoresistiveShockAccelerometers...............................................50

CharacterizationofaNewAcceleratedDropTowerforShockTesting.......................................................................50

DEDICATEDSESSION:BLAST,PROGRESSIVECOLLAPSE,&POSTDISASTERPERFORMANCEOFINFRASTRUCTURE

StateofProgressiveCollapseKnowledgeandResearch.............................................................................................50

Newfindingsonprogressivecollapseofbuildingsandglobalstructuralintegrityofdamagedstructures................50

DevelopmentofthePostDisasterAssessmentTool(PDAT).......................................................................................51

EffectsofBlastLoadLocalandGlobalResponsesonHighwayBridges......................................................................51

NanomaterialsforInfrastructureProtection&Security.............................................................................................51

MultiDisciplinaryAspectsofTunnelSecurity.............................................................................................................52

INNOVATIONSINSENSORTECHNOLOGY&DATAMANAGEMENT

DevelopmentofaCriticallyDamped2000GMEMSAccelerometer...........................................................................52

LowNoise,HighRangeStrainMeasurementsat2MHz..............................................................................................52

PerformanceCharacterizationofPrecisionInertialAccelerometers..........................................................................52

AmendmenttoISO1606322:2005,"MethodsforthecalibrationofvibrationandshocktransducersPart22:Shockcalibrationbycomparisontoareferencetransducer".....................................................................................53

RapidDesignCyclesandExplosiveDataGrowthinEngineeringTest.........................................................................53

VIBRATIONMODELING,SIMULATION,&ANALYSIS

Severalaspectstobeconsideredinthedefinitionofalaboratoryvibrationsimulationprogramforairbornestoresincaptivestraightflight...............................................................................................................................................53

Reconstitutionofadisruptedmissilefreeflightmeasuredvibrationtimehistory....................................................54

Criteriafortheevaluationoftheequivalencebetweenafreeflightmeasuredvibrationtimehistory,andamathematicallyreconstitutedorshakersimulatedversion........................................................................................54

SynthesisofaPSDCompatibleAccelerationTimeHistory.........................................................................................55

DesigningstructurestowithstandhighspeedfluidimpactswithAbaqus/ExplicitCEL............................................55

DissipatedEnergyLifeModelofaCantileveredBeamSubjecttoRandomVibration................................................56

DEVELOPMENT&VALIDATIONOFTHELARGECAPACITYDECKSIMULATORFIXTUREFORMILS901DHEAVYWEIGHTSHOCKTESTING

Requirements,Production,andTestingofaLargeCapacityDeckSimulatorFixtureforMILS901DHeavyweightShockTestingofHeavyEquipmentatLowFrequencies.............................................................................................56

DesignandAnalysisofaLargeCapacityDeckSimulatorFixtureforMILS901DHeavyweightShockTestingofHeavyEquipmentatLowFrequencies...................................................................................................................................56

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FabricationofaLargeCapacityDeckSimulatorFixtureforMILS901DHeavyweightShockTestingofHeavyEquipmentatLowFrequencies...................................................................................................................................57

MATERIAL/STRUCTURERESPONSE

ValidationStudiesfortheReleaseIIIK&CConcreteModel........................................................................................57

TheTransitionfromtheInversetoClassicalHallPetchPhenomenoninSingleCrystalCopperunderImpactLoading.....................................................................................................................................................................................57

NewInsightintoGraniticRockTargetDamagefromMacroscopicandMicroscopicstudyofrecentEarthPenetratorevents..........................................................................................................................................................................58

Synthesis,Microstructure,andExplosivePropertiesofSprayDepositedSilverAcetylideSilverNitrateCompositeLightInitiatedHighExplosives.....................................................................................................................................58

EvaluationofResidualCapacityofCompositePressureVesselsAfterImpactEvents................................................59

AnInvestigationintoVentingSolutionsfortheM548AmmunitionContainerduetoitsContentsIgniting..............59

DEDICATEDSESSION:STUDIESINSUBMARINESTRUCTURES&SYSTEM

ComparisonofToroidMountedandBulkheadMountedIsolatedDeckModule(IDM)ConfigurationsforaSubmarinePayloadModule(PM)................................................................................................................................60

EvaluationoftheNonPressureInfluenceonDynamicHullStabilityforaDoubleHullSubmarineCompartment....60

AlternativeIsolationDevicesforDeckModulesDesignedforCOTSEquipment.......................................................60

AComparisonofSeveralIncidentFieldModelsforAssessingtheShockResponseofSubmarineStructures.........60

TubeHatchAssemblyShockDesignAnalysisApproach..............................................................................................60

INSTRUMENTATION&MEASUREMENTTECHNIQUES

TestingAntiRamBarrierProtectionSystemsattheLarsonInstituteCrashSafetyResearchFacility........................60

ImprovedDataAcquisitionMethodsforShaftAlignment..........................................................................................61

UsingDigitalImageCorrelationforHighAccuracyMeasurementsinAirBlastTestEnvironments...........................61

DeflectionMeasurementSolutionsforAirBlastTestingofProtectiveWindowSystems..........................................61

FreePseudovelocityShockDataAnalysisSoftwareUsingGNUOctave......................................................................62

BLASTPROTECTIONTECHNOLOGIES

ExperimentalTestingofHighStrengthSteelStudWallSystemforEnhancedBlastProtection.................................62

AnalyticalValidationandDesignGuidelinesofInnovativeBlastResistantSteelStudWallSystem...........................63

NumericalSimulationsandTestingValidationofRetrofittedPrefabricatedCompositeSteelStudBlastPanels.......63

BlastAndFragmentationEffectsOfCloseRangeDetonationsAndRelatedMitigationTechniques..........................64

DevelopmentofShallowFoundationStreetscapeVehicularAntiramSystemsthroughModelingandTesting.......64

NewDevelopmentsinaBlastMitigatingSystemMadeofLaminatedPolycarbonateforExteriorBuildingProtection.....................................................................................................................................................................................64

DEDICATEDSESSION:UQ/V&VOFLARGESTRUCTURESTOSHOCKLOADING

UQ/V&Vforlargescalestructuressubjecttodynamicshockloading........................................................................65

BootstrapMonteCarlousingadaptivestratifiedsamplingforUQ/V&Voflargestructuressubjecttoshockloading.....................................................................................................................................................................................66

AssessmentofValidationMetricsforUNDEXSimulations..........................................................................................66

WEAPONSYSTEMS&MUNITIONSSTUDIES

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FragmentationCharacterizationofaNaturallyFragmentingCasedMunitionwithaLargeLengthtoDiameterRatio.....................................................................................................................................................................................67

ANovelApproachtoa100PercentFragmentCaptureTestofaLargeNaturallyFragmentingCasedMunition.......67

StressTestingofMortarBaseplatesMethodandValidation...................................................................................67

DynamicsoftheSafeandArmAssemblyintheM739A1FuzeduringGunLaunchandProjectileFlight...................68

ModelingandSimulationoftheZigzagSetbackPinforFuzingApplications..............................................................68

ComparingofHydrocodesforPredictinganExplosiveSequence...............................................................................69

DEDICATEDSESSION:STUDIESINSUBMARINESTRUCTURES&SYSTEMS

CharacterizationofShockEnvironmentforaShockIsolatedDeckModule...............................................................69

BLASTMITIGATIONFORCRITICALINFRASTRUCTURE

LightweightMicroTrussPanelsforProtectingCriticalInfrastructureFacilitiesfromHighIntensityNearFieldAirBlastEvents..................................................................................................................................................................69

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UNDEXNUMERICALMETHODS&APPLICATIONSI

APPLICATIONOFANRKDGDGFMW/ALEMETHODTOMODELUNDERWATEREXPLOSIONSDr.AlanBrown,VirginiaTechLCDRJinwonPark,ROKNThispaperpresentsthemotivationanddevelopmentofaRungeKuttaDiscontinuousGalerkinDirectGhostFluidMethod(RKDGDGFM)tomodelUnderwaterExplosions(UNDEX)andassessestheeffectivenessofthismethodtomodelanexplosion insideawaterfilledtube.Thesmallchargeexplodesatthe innercenterofthetubeandthetubewallisdeformedbythehighpressureloading.Thewalldeformationmodifiestheexplosionfluidflowintheregionnearthewallandhassubstantial influenceontheresponseofthestructure.Tomodelthefluidstructureinteraction,validdataexchangealongtheinterfaceisnecessaryincludingsurfacepressure,interfacedisplacementand velocity.Classical FluidStructure Interaction (FSI) simulations typicallyemploy amatchedmeshing schemewhichdiscretizes fluidandstructuremeshesusingasinglemeshdensity.Thesizeof themesh required for thestructure is substantially smaller than that required for the fluid so the fluidmeshmustbemuch smaller thannecessary for solution in the fluid. This makes the computation much more expensive. To reduce thecomputationalcost,anonmatchedmeshingschemewhichallowsfordifferentmeshdensitiesisused.Theresultsand computational efficiencyof this simulation are compared to experimentaldata and resultsobtainedusingothermethods.ADIRECTGHOSTFLUIDMETHOD(DGFM)FORMODELINGEXPLOSIVEGASANDWATERFLOWSDr.AlanBrown,VirginiaTechLCDRJinwonPark,ROKNThispaperpresentsatwofluidmethodsuitabletomodelexplosivegasandwaterflowsresultingfromnearfieldunderwater explosions (UNDEX). Because of the presence of explosive gas andwater in the domain, classicalEulerianmethodshavinginherentdiffusionarenotdirectlyapplicable.Numericaldiffusionresultsinnonphysicallydiffuseddensityatthematerial interface.Diffuseddensitycancreatespuriouspressureoscillations invicinityofthematerial interface. Spurious pressure oscillationsmay cause the sudden abortion of fluid computations ordegrade thequalityofnumerical results.Toeliminateorminimizenumericaldiffusion,sharp interfacemethodshavingnomixedelementsmaybeusedinthemultifluidflowcomputations.ADirectGhostFluidMethod(DGFM)using the direct extrapolation of density across thematerial interface is presented and a procedure tomodelinterfaceconditionsisexplored.THEINFLUENCEOFVAPORBUBBLESINTHEMITIGATIONOFUNDERWATEREXPLOSIONSTRUCTURALLOADINGMr.JaremaDidoszak,NavalPostgraduateSchoolLTStevenArbogast,UnitedStatesNavyDr.YoungKwon,NavalPostgraduateSchoolDuring an underwater explosion event, a bulk cavitation zone is created near the airwater interface. Thiscavitationzonecanbedescribedasathinvolumeofwatertornintobubblesatvaporpressure.Disruptionsinthewatercolumnduetothisspalledwater layerhavebeenshowntoaltertheshockwavepropagationthroughthisregion. This research focuses on the presence of various sized bubble fields positioned along the slant lineextendingbetween an explosive source and a semisubmerged structural target. The influenceof varying thediameter,centertocenterspacingandlayeringdistancesofthediscretelymodeledbubbleswasinvestigated.TheDYSMAShydrocodewasusedtosimulatetheresultingeffectsofpressureloadingandstructuralresponseonthetarget from the introductionof these interferences into the shockwavepropagationpath. Additionally,meshsensitivity of the Eulerian fluid in proximity to the bubbles was also investigated to better understand theinteractionof thepressure causedby their inclusion, size, composition and spacing. Resultspertaining to thebuffering effects of the bubble fieldwill be presented alongwith other findings on themodeling techniquesemployed.

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DYNAMICRESPONSEOFACOMPOSITEPROPELLERBLADESUBJECTEDTOSHOCKANDBUBBLEPRESSURELOADINGDr.ChaoTsungHsiao,Dynaflow,Inc.Dr.GeorgesChahine,Dynaflow,Inc.Theinteractionbetweenanunderwaterexplosionandacompositepropellerinvolvesseveralphysicalphenomenathatanaccuratenumericalsimulationneedstocapture.These includeproperdescriptionofthe initialexplosionshockwaveand itspropagationand interactionwiththepropellerbladesandanyotherneighboringboundaries.The shockwave is followed by the formation of an UNDEX bubblewhose dynamics are responsible for longduration loads and resultingpropellerdynamics. The resulting impulse loadingof the structure couldbeof asimilartimescaleastheresponsetimeofthecompositestructuremotionandcouldresultinlargescalefailure,i.e.survivaltotheinitialshockmaynotbesufficienttoqualifythecompositepropeller.In the present study a numerical procedure which links the compressible flow solver, Gemini with anincompressible flow solver, 3DYNAFSprocedure has been applied to capture both shock and bubble phasesefficientlyandaccurately.Bothflowcodessolvethedynamicswhileintimatelycouplingthesolutionwithafiniteelementstructurecode,DynaN,toenablesimulationofthefullfluidstructureinteraction.Aparametricstudywasconducted on the effects of explosive chargeweight, standoff distance between charge and propeller, chargedepths, and composite material composition and properties to understand their effects on the propellersurvivability.Multilayeredpropellersmadeofdifferentcompositematerialswithdifferentfiberorientationswerealso studied tounderstandwhichmaterialsand fiberorientationsgive the strongestpropeller in termsofbothbendingandtwistingresistance.STUDYFORTHECLOSEPROXIMITYUNDERWATEREXPLOSIONPROBLEMUSINGSIMPLIFIEDSHIPMODELDr.JeongIlKwon,KoreaInstituteofMachinery&MaterialsDr.JungHoonChung,KoreaInstituteofMachinery&MaterialsDr.YunHoShin,KoreaInstituteofMachinery&MaterialsMr.YeoHoonYun,KoreaSimulationTechnologiesRecently, the vulnerability of the warship's behavior through Cheonan sinking incident in Korea has beenconfirmedduetotheshock loadingcausedbythecloseproximityunderwaterexplosion.Fromthis incident,theassumptioncanbepossibletobe likethatanykindofwarshipcannotbeavoidedthecriticalcasualtyundertheshock condition induced Cheonan sinking incident and therefore, any protection design method should benecessary todecrease thedamage resulting in a sinkorprevent the crew resulting indeath andeven greaterdamage. Inthisstudy,acloseproximityunderwaterexplosionanalysishasbeencarriedoutusingthesimplifiedshipmodel and the shock damage behavior andmechanismwas analyzed. Through this analysis process, theconceptualdesign improvementmethodtoat leastsecurethe longitudinalhullgirderstrengthhasbeentriedtofindoutaspreliminarystudy.SHOCKRESPONSEANALYSIS&EVALUATIONFORONBOARDEQUIPMENTACCORDINGTOAPPROACHMETHODOLOGYBASEDONTHEDESIGNREGULATIONDr.JeongIlKwon,KoreaInstituteofMachinery&Materials Dr.JungHoonChung,KoreaInstituteofMachinery&MaterialsDr.YunHoShin,KoreaInstituteofMachinery&MaterialsMr.TaeMukChoi,CreatechCo.Ingeneral,theshockresistanceperformanceofonboardequipmentinstalledinwarshipagainsttheshockloadingcausedbyunderwater explosion shouldbeproved and for thispurpose a validationprocessusing the specificshocktestandanalysis inaccordancewiththerelevantspecificationandrulehasbeenconductedeachcountry.Currently,Typicalapproachmethodology in this regard isU.S.Navy regulationsDDAMandMILS901Dand theGermanNavyregulationsBV043beingusedasarepresentative.InKorea,becausethereisnolargetestfacilityfortheverificationoftheshockhardeningperformanceforheavyweightedequipmentsuchasengineorgeneratorsystem,ananalytical/numericalapproachmethodhasbeenusedwidelyforthethisresponseanalysisandstudycurrently.Inthisstudy,thenumericalanalysisforMILS901Dheavyweightshocktestandthetransientanalysis

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usingBV043shockdesignspectrumhasbeencarriedoutandevaluated individually foran idealizedsystem forlargeequipment.Finally,withtheseshockresponseresult,theshockresponseresultthroughthenumericalshipshockmodelingandsimulationusingLSDYNA/USAhasbeencomparedandanalyzedtheresponsecharacteristic.

STRUCTURALRESPONSETOBLASTLOADINGMODELINGCONCRETEEROSIONSTRAINFORBLASTRESISTANTDESIGNProfessorAndrewWhittaker,UniversityatBuffaloProfessorAmjadAref,UniversityatBuffaloMr.JinwonShin,UniversityatBuffaloMaterial erosion is used for simulations of damage to structural components under blast loadings. Erosion ofelementsfromameshisbasedonuserspecifiedcriteriathatareexploredinthepaper.Singleelementsimulationsof concrete are performed to establish reliable values of concrete erosion strain as a function of strain rate,compressive strength, element size and loading condition. Blast loading simulations of a reinforced concretecolumnareperformedtoidentifytheimportanceofselectinganappropriatevalueoferosionstain.DYNAMICANALYSISONMEMBRANEEFFECTOFONEWAYSUPPORTEDSTRUCTURESTORESISTTRIANGULARPRESSURELOADMr.YonghuiWang,NationalUniversityofSingaporeThe damage level of oneway supported structureswithmembrane effect subjected to uniformly triangularpressureloadwasstudiedinthispaper.AshapefunctionwasderivedandusedtosimplifytheactualstructureintoequivalentSingleDegreeofFreedom(SDOF)system.Thestrainexpressionwasderivedandsimplifiedtosecondorderpolynomialofmidspandisplacementtospanratio,whichisthenusedtogenerateresistantfunctionfortheSDOFsystem.ThedisplacementtimehistorywasobtainedbyutilizingAverageAccelerationMethod.Thecircularnatural frequency was obtained as function of mass, stiffness and initial velocity. The relationship betweendimensionlessmaximumdisplacementandloaddurationtostructuresnaturalperiodratewasconstructed,basedonwhich; the dimensionless PressureImpulse diagramwas established through curvefitting of dimensionlesspressure and impulse. The PressureImpulse diagram can be used to determine the damage level of actualstructuresubjectedtotriangularblastpressureload.ThedamagelevelcalculatedusingthederivedequationsforseveralcasestudieswereshowntoagreewellwithFEresults.LIMITATIONSANDCONSEQUENCESOFFRAGMENTPROTECTIONFORNEARFIELDAIRBLASTMEASUREMENTSMr.AlexanderChristiansen,BakerRiskMr.DavidBogosian,BakerRiskObtainingpressureandimpulsedatafromexplosionswherefragmentsarepresentcanbechallenging.Onewayofprotectingairblastgaugesfromdamageduetofragmentdebrisistoplaceasmallbutphysicallyrobustobstructiondirectlybetweenthechargeandthetarget.Typically,averticalmetalpole (steelpipe,usually) ispositionedtenpolediametersawayfromthegaugedirectlyinlinebetweenthechargeandthegauge.Thepresenceofthispipe,however,reducestheamountofblastenergythatreachesthetargetandaffectsthemeasuredpressurerecord.Awidely implemented ruleof thumb suggests thatplacing thepoleatastandoffof tenpolediameters from thegaugecausesanegligiblereductionintheairblastimpulsethatreachesthetarget.Theeffectofsuchobstructionsonnearfieldairblastmeasurementshasbeeninvestigatedusingthe2DArbitraryLagrangianEulerian(ALE)andfluidstructureinteraction(FSI)capabilitiesofLSDYNA.Bothasinglepoleaswellasanarrayof threeadjacentpoleswereanalyzedand compared to resultswithoutanyobstructions.The resultsprovidevaluableinsightsintothesensitivityofpressureandimpulsemeasurementstothenumber,diameter,andpositionoftheseobstructions.Theseobservationscanbeusedtoassistininterpretinggaugerecordsfrombehindthesepolesaswellasindesigningtestbedlayoutsthatminimizetheeffectsofpolesontheresults.

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INNOVATIVEBLASTRESISTANTDESIGNOFSTEELSTUDWALLSYSTEMSACCOUNTINGFORCOMPOSITEBENDINGANDCONTROLLEDHINGEFORMATIONMr.CaseyOLaughlin,JacobsTechnologyMs.AdyAviram,Simpson,GumpertzandHegerMr.RonMayes,Simpson,GumpertzandHegerMr.RonHamburger,Simpson,GumpertzandHegerRecentblastvalidationofaninnovativesteelstudinfillwalldesignperformedattheAirForceResearchLaboratory(AFRL)locatedatTyndallAirForceBase,Floridahasshownthatthroughdetailingconnectionsandsheathing,thedesignercanchangetheresponsemodeshapeofthestuds.Theresultwasahighlevelofprotectionagainstmuchgreaterblast loads than specified in theUnifiedFacilitiesCriteria (UFC) for steel studwalls innewandexistingbuildings.Previoussteelstudcurtainwallsystemsdesignedandtestedagainstthethreat,specifiedbyUFC401010,utilizedstandardscrewtypeconnections,commonsheathingproducts,andmildsteelstuds.TherecentblastvalidationexperimentsatTyndallAirForceBasebuildsonthatpreviousresearchbyimpartingablastloadoffourtimesthemagnitudeoftheUFCthreatintoasteelstudwallconsistingofmildsteel,typicalstudlayout,andsimpleconstructiondetailspreventingundesirablefailuremodes.Thewallsystemachievedahigh levelofprotection intermsofdamagedescriptionprovidedbytheUnitedStatesArmyCorpsofEngineersProtectiveDesignCentersguidelineswithanestimatedcostof$25$27persquarefoot.Itisestimatedthatbyuseofthesetypesofsystemsthematerial costs associatedwith the constructionof facilities that requireprotection to these typesof loadscouldbereducedsignificantly.HighfidelityfiniteelementmodelsdevelopedbySimpsonGumpertzandHegerforthisinnovativeblastmitigationsystemusingABAQUS/Explicitwereabletopredictthepeakandresidualresponseof thewallwithin5%accuracy.Theresponseof thesystemwassuccessfullycapturedby theanalyticalmodels,initiallyvalidated throughaseriesof fullscaleblastsimulation testsattheUniversityofCalifornia inSanDiego.StaticresistancefunctionsofthewalldesignwereobtainedatTyndallAirForceBasewiththeuseofAFRLsloadtreetestingdeviceandthenincorporatedintobothsingledegreeoffreedomandfiniteelementdynamicanalysisprocedures toconfirm theaccuracyofeachanalysismethod.Blast testingcarriedoutatTyndallAirForceBaseusingliveexplosivesandactualblastpressurefurthervalidatedthewallprototypefortheretrofitofunreinforcedconcretemasonrywalls.CONNECTIONDESIGNOFSTEELMEMBERSSUBJECTEDTOBLASTLOADINGMr.DavidHolgado,ABSConsultingMr.DarrellBarker,ABSConsultingDr.ManuelDiaz,ABSConsultingMr.WilliamLeBoeuf,ABSConsultingSteelmemberssubjectedtoblastloadingaretypicallymodeledwithboundaryconditionsasfullyfixed,pinnedorcantilevered. However, connections in real structures are more complex with actual boundary conditionbehaviorsomewherebetweenfixedandpinned.Often,thetruenatureofconnectionsmayvaryateachendofthemember.Overallresponseofmemberdependsinlargepartontheconnectioncapacityaswellasductilityoftheconnection.Additional inplane forcesaswellasrotationalrestrictionattheend(s)ofthemember,otherthantypicalshearreactions,canimprovethefinalresponseofthemember.Creatingmodelsthatincludeflexureofthemember,aswellasmorerealisticboundarysupportconditions,willgeneratealessconservativeoveralldynamicresponseofthemember.ThispaperpresentsaSingleDegreeofFreedom(SDOF)approachtocomputetheoverallresponseofamembersubjected toblast loadingusingnonlinearmodels (includingmaterial and geometricproperty considerations).Using thenonlinearmodelsaTwoDegreeofFreedom (TDOF)approach isdeveloped.Thehigher fidelityTDOFmodel can predict amore realistic response of the system subjected to blast loadingwhich, in turn, providesdeflections aswell as reaction forceswhichmay be used in the design of connections. Several examples aregenerated and also a comparison of deflection response with conventional SDOF analysis is shown incorrespondingtables

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DEDICATEDSESSION:UNDERWATEREXPLOSIONLOADING

AMETHODFORFITTINGWATEREOSPARAMETERSFORUNDERWATEREXPLOSIONSIMULATIONSDr.ThomasMcGrath,NSWCIndianHeadDivisionMr.MartinMarcus,NSWCIndianHeadDivisionMr.AlexMeissner,NSWCIndianHeadDivisionAccurate computationalmodeling of underwater explosion (UNDEX) events is of critical interest to theUnitedStatesNavy. The fullycoupled hydrocode DYSMAS has been developed specifically formodeling underwaterexplosionsandtheireffectsonnavalstructures.TheaccuracyofcomputationalresultsobtainedwithDYSMASisafunction of both the numericalmethods andmaterialmodels used in the code. The fluid solver inDYSMAS,Gemini, isdistributedwitha standardequationof state (EOS) librarydescribing commonly simulatedmaterialssuch as air, water and high explosives. While the EOS for water has proven useful and accurate in manysimulations,thepropertiesofwatervarywithlocationandconditionssuchastemperatureandsalinity.AdjustingtheEOS coefficients forwater tomatch local conditionsat the test site isnecessary tomoreaccuratelymatchexperimentaldata.ThispaperpresentsamethodfordeterminingtheEOSparametersforwaterthatisshowntoimprovetheaccuracyofUNDEXsimulations. Themethod isbasedonmatchingtheexperimentallymeasuredsoundspeedofwateratthe test site while reproducing a benchmark Hugoniot over the range of pressures encountered in UNDEXscenarios.DetailsoftheEOSfittingmethodarepresented,andasetofEOScoefficientsforwaterattheNationalTechnical Systems, Inc. (NTS) quarry test site are generated. Results fromGemini simulations using both thestandard EOS coefficients forwater and those fit for theNTSquarry are comparedwith existing experimentalmeasurementsfromUNDEXtests.DETERMINATIONOFSEABOTTOMPROPERTIESUSINGUNDERWATEREXPLOSIONPRESSUREDATAMr.MartinMarcus,NSWCIndianHeadDivisionMr.GregHarris,NSWCIndianHeadDivisionUnderwater explosion loading in shallowwater is of interest tomany aspects of navalwarfare. The complexpressurefieldfromalargeunderwaterexplosioninshallowwaterisstronglyinfluencedbytheproximityoftheseabottomand thewater surface. Simulationof theUNDEXevent requiresanaccuratedescriptionof thebottomcomposition,which is often not available. By using themeasured bottomreflected shockwave data, the seabottom properties can be discerned. Experimental test data from a recent test series is used to illustrate theprocess.Once thebottomhasbeenproperly characterized, credible simulationsofUNDEXevents in thewatercolumn(thispresentation)orontheseabottom(followingpresentation)canbemade.DYSMASSIMULATIONOFTHEUNDERWATEREXPLOSIONSHOCKWAVELOADINGFROMALARGECHARGEONTHESEABOTTOMMr.MartinMarcus,NSWCIndianHeadDivisionMr.GregHarris,NSWCIndianHeadDivisionTestdatafroma largeseaminedetonatedontheseabottom isanalyzedusingtheDYSMAShydrocode.TheseabottompropertiesweredeterminedfromotherUNDEXtestdataatthesametestsite(previouspresentation).Astrongheadwavewasobserved in thedata. Pressure comparisonsbetweenDYSMASandexperimentwere ingoodagreement,includingreproducingtheeffectsoftheheadwave.

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ANIMPROVEDPENTOLITEJWLEQUATIONOFSTATEFORUNDEXSHOCKANDBUBBLESIMULATIONSMr.JeffreySt.Clair,NSWCIndianHeadDivisionDr.ThomasMcGrath,NSWCIndianHeadDivisionSimulationofunderwaterexplosion (UNDEX)events isof interesttomanynavalapplications. ThefullycoupledhydrocodeDYSMAShasbeendevelopedspecificallyformodelingunderwaterexplosionsandtheireffectsonnavalstructures. The accuracy of computational results obtainedwithDYSMAS is a function of both the numericalmethodsandmaterialmodelsusedinthecode.ThefluidsolverinDYSMAS,Gemini,isdistributedwithastandardequationofstate (EOS) librarydescribingcommonlysimulatedmaterialssuchasair,waterandhighexplosives.EOSparameters formanycommonexplosivesare takendirectly from the literatureandwerederivedbasedoncylinderexpansionor inairexplosion testdata. As theEOSparameterswerenotdevelopedwithunderwaterexplosions inmind,casesexist inwhich they fallshortofaccuratelypredictingunderwaterperformance. Mostnotably,bubbleperiodsandpressuresmaybe inerror. Thiswasthecaseforthestandardexplosivepentolite.Duetotheuseofpentoliteformanyprecisiontestingapplications,thepentoliteJonesWilkinsLee(JWL)EOSwasrevisitedand refit toprovidemoreaccuracy forUNDEX simulations.Thispaperdescribes theprocessusedandprovidesvalidationexamples.VALIDATIONEXAMPLESUSINGTHEIMPROVEDPENTOLITEEOSDr.BradleyKlenow,NSWCCarderockDivisionTheimprovedPentoliteJWLequationofstate(EOS)istheresultofaNSWCIndianHeadDivisionefforttorefitthePentolite JWL coefficients to better simulate the loading that results from the oscillation of an underwaterexplosive (UNDEX) bubble. Using available test data and empirical calculations, this paper compares theperformance of the improved Pentolite JWL EOS to the standard Pentolite JWL EOSwhen applied to UNDEXproblems that involve combined shock and bubble loadings. One of the significant faults when applying thestandardPentolite JWLEOS to suchUNDEXproblems is convergence toan inaccurate solution.Toaddress thisconcern, resultsgenerated frommultiple fluidgrid resolutionsarediscussedand theaccuracyof thepredictedshockwave,bubbleperiod,andbubblepulseisevaluatedforeachEOS.TheresultsofthisassessmentshowthattherevisionsmadetothePentoliteJWLEOSdoimprovetheaccuracyofUNDEXsimulationsthatinvolvecombinedshockandbubbleloadings.AdditionallyitwasfoundthattheimprovedPentoliteJWLEOSsolvestheconvergenceissueencounteredwhenusingthestandardEOS.

INSTRUMENTATIONMETHODSCHARACTERIZATIONOFDAMPEDACCELEROMETERSWITHFULLRANGEHOPKINSONBARSHOCKMr.JamesLetterneau,Meggitt,SanJuanCapistranoMeggittSensingSystemshasdevelopedafamilyoflightlydampedhighgshockaccelerometerswhichareavailableinvariouspackageconfigurationsinboth20,000gand60,000granges.InanattempttofurthercharacterizetheperformanceofthedampedaccelerometeraseriesoffullrangeHopkinsonbartestinghasbeenconductedattheENDEVCO shock laboratory.Performance characteristicsdiscussed include timedomainamplitude linearityandfrequencydomaincharacteristicswhicharecompared to thecharacteristicsof the industrystandardundampedaccelerometers. Additionally, it is shown that these accelerometers meet the new MILSTD810G, Change 1requirementofvibrationcalibrationandshockamplitudelinearityresultsshouldagreewithin10percentovertheamplituderangeofinterestforagiventest.MINIATURIZEDHIGHGSHOCKTRIAXIALACCELEROMETERSMr.RandallMartin,Meggitt,SanJuanCapistranoMr.JamesLetterneau,Meggitt,SanJuanCapistranoAnewminiaturizedhighgshocktriaxialaccelerometerhasbeendevelopedthatusesthesameundampedMEMSsensingelementastheindustrystandard7270A.Itfeatures3orthogonalaxesofshockdatameasurementinthe

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same footprintandboltpatternas the traditionalboltmountpackagemaking itadropin replacement for thesingle axis device. Test data is presented and performance characteristics including transverse sensitivity andshock survivability are discussed. Issues related to the testing of triaxial accelerometers are discussed and acustomtestfixtureaddressingtheseissuesispresented.Inaddition,preliminarytestresultsofalightlydampedtriaxinthesameminiaturepackagearepresented.LABORATORY PRESCREENING METHOD FOR PREDETONATION MATERIALS AGAINST PLUNGERTYPE FUZED MORTARS USING ANINSTRUMENTEDINERTFUZEMr.SamuelMisko,JacobsTechnologyLt.JohnHeld,UnitedStatesAirForceIn an effort to establish a laboratory prescreeningmethod for predetonationmaterials against plungertypefuzedmortars, a laboratory studywas conducted to validate theuseof an instrumented inertmortar fuze forcandidatepredetonationmaterialevaluation inadropweight testapparatus. Two instrumented inertmortarfuzesweredevelopedinanefforttoquantifyeachcandidatematerialsabilityto(1)exertforceontheplungerand(2)depresstheplunger.Onefuzewasinstrumentedwithapiezoelectricloadcellanddesignedtorecordtheforceat the approximate location of the fuze plungers strike plate. The second fuze was instrumented with asubminiatureDVRTanddesignedtorecordthedisplacementofarepresentativefuzeplunger.Eachofthedetailsthataffectthearminganddetonationofthefuzewereconsideredandreplicated, includingthewindscreenandinternalplungermechanics.Thestudyfocusedon27differentpredetonationmaterials,eachofwhichwastestedthreetimesattwodifferentangles(60and90)withregardstothelineoffire.Thesponsorofthisprogram,USArmy Corps of Engineers Engineer ResearchDevelopment Center,will use the results of this test program toquantify the effects of low velocity laboratory prescreening methods as compared with both high velocitylaboratoryprescreeningmethodsandlivefiremortartesting.

AIRBLASTDATA&ANALYSISGUIDETONUCLEARAIRBLASTRECORDS:AREPORTSUMMARYMr.JeffreyThomsen,AppliedResearchAssociates,Inc.Anefforttocatalog,digitizeandpreservesurfaceandabovegroundairblastrecordsfromnucleareventshasbeencompletedoverthepast15years.TheeffortsculminatedinareporttitledAGuidetotheNWETINuclearAirblastRecordInventory(DTRIACSR11003,Vols1and2,Aug2011),publishedbytheDefenseThreatReductionAgencyInformationandAnalysisCenter(DTRIAC).ThecomprehensiveAirblastGuide,whichaccompaniesthedigitalfilesofallrecoverableairblastrecords,waswrittenbyMr.FredM.Sauer(19222010).Mr.SauersobjectivesinwritingtheAirblastGuidewere(a)toprovidearoadmaptotherecordscontainedintheAirblast record inventory, (b) toprovideabriefhistoricalsummaryof theexperimentaleventswhich led to thecollectionoftheairblastrecordscontainedintherecordinventory,(c)todescribethestateoftheartofairblastdataanalysisduringthefirstseveralnucleartestoperationsandhowthatanalysisprogressedasnewinformationresulted from smallscalehigh explosive experiments, (d) toprovide adescription of the instrumentation andgaugesusedby theairblastexperimenters, (e) tohighlight the influenceofpressuregauge response inshapingoverpressurewaveformsand thedeterminationofmaximum incidentand reflectedpressures, (f) tosummarizetheairbornecanisterdataandaddnewanalysisof this freeair information, (g) topresentnewanalysesof thereflectedpressuredataand,(h)toprovideadescriptionofrecordingmethodsanddataprocessingmethodsusedtoreproducetheairblastrecordscontainedinpreviouslypublishedreports.Thepurposeof thispaper is tomake theexistenceof theAirblastGuideknown to thephysicsandengineeringcommunitiesbywayofadetailed introductiontothecontents,examplesofrecords,andcomparisonofrecordswithanalyticalroutinesforcalculatingnuclearairblastwaveforms.ItisexpectedthattheAirblastGuide,itsdigitalrecordsand itsextensivereference listswillcontinuetobeuseful longafteralloftheactualexperimentersandothertechnicalpersonnelwhowere involved inthenucleartestoperationshaveretired,alongwithmostofthe

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technical personnelwhodigitized andprepared theNumericAirblast Inventory.Consistentwith the resourcesavailable and in order tomaintain overview and perspective, the AirblastGuide is necessarily brief, and thussomewhatlimitedinbothscopeanddepthofthesubjectmatter.Anoverviewofthetheoreticalaspectsofairblastreflectionispresentedtoacquaintthereaderwithgapsinourknowledgeofairblastphenomenologynotfilledbycurrentlyavailableairblastdata.TheAirblastGuideprovides theuserwitha roadmap toover3,700airblast records contained in theNumericAirblast Inventory,with the records themselves contained inVolume2of theGuide, in a standardized formatprovided for reading/writing theunique Inventory recordTitlesandReferenceFileNames (RFNs)aswellas forplottingandstoringrecordsonlocalharddisks.SALVAGINGAIRBLASTIMPULSEDATAFROMSHIELDEDGAUGESMr.DavidD.Bogosian,BakerEngineering&RiskConsultantsMs.AllisonYu,BakerEngineering&RiskConsultantsMr.AlexChristiansen,BakerEngineering&RiskConsultantsExperiments involving cased charges typicallyusephysicalmeasures toprotect airblast gauges from impactofcasingfragments.Theseobstructionsaremadetobesmallinsizeandarepositionedsomedistanceawayfromthegauges.Theshockfrontispresumedtoreformbehindthepole,andprovidedthepolesdiameterissmallanditsdistancefromthegaugeislarge,theeffectontheairblastdatashouldbeminimal.In a recent seriesof experiments conductedby theAir ForceResearch Laboratory at EglinAFB, Florida,8.5 lbcylinders of Composition B chargeswere surrounded by rings of prescored steel fragments. Three poleswerepositionedtoscreenatotaloffiveairblastgauges,providingasignificantamountofdata.Thegaugesproducedairblast impulse levelsthatwerenotonlymuchsmallerthanthose frombarecharges,butalsodemonstratedafundamentallycounterintuitiveandnonphysicalrateofattenuationvs.standoff.Intheiroriginalstate,thisdatacouldnotbeusedtocharacterizetheairblastimpulseproducedbythecasedcharges.Asetoftwodimensionalcomputationalfluiddynamics(CFD)calculationswereperformedtoinvestigatetheeffectofpolesinbiasingthereadingsofthosegauges.Calculationsweremadewithandwithoutpolesandtheresultingdecrease in impulsewas documented as a function of standoff. This analytical resultwas then validated (andcalibrated)bycomparisontodatafromasinglebarechargetestsinwhichthesamearrayofverticalpoleswasalsofielded. The comparison showed that the 2D CFD results underestimated the level of shielding (and impulsereduction)producedbythepoles.Byusingthisoneexperimentaldatapoint,thereductionfactorsobtainedfromtheCFDanalyseswerescaledandthenusedtoadjustthemeasuredimpulses.Inthiswayareliableestimateoftheairblastimpulsefromthecasedchargecouldbebackedoutoftheavailabledataandusedforfurtheranalysis.Theseresultsweremuchmoreinlinewithexpectations,andalsocomparedfavorablytosimplisticpredictionsofthecasingeffectbasedontheFanoequationprovidedintheDAHSCWEManual(UFC334001).

MULTIAXISVIBRATIONONCONTROLLING6DOFELECTRODYNAMICTABLESMr.RussAyres,SpectralDynamics,Inc.Dr.MarcosUnderwood,SpectralDynamics,Inc.Mr.TonyKeller,SpectralDynamics,Inc.

Manycurrent6DegreeofFreedomvibrationtestsareperformedusingHydraulicexciters,withupperfrequenciesrangingfrom100to500Hz.However,thereareapplicationsfor6DOFtestingwhichrequireControluptoatleast2,000Hz.Inthesecases,anapproachusingElectrodynamicshakersisrequired.

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Controlling Random, Sine, Shock and TimeWaveforms on 8 ED shakers to 2,000Hz requires a unique set ofcapabilitiesinsignalgenerationandcontrol.Italsorequiresdynamiccouplingmechanismswhichwilltransmittherequireddrivesignalswithoutdamaging the respectiveshakerarmatures.When these requirementshavebeenachieved, theoptimumcontrolstrategymustbeselected.Thiscanbechosen fromSquareControl,RectangularControl or Coordinate Transformation Control. No matter which approach is selected, CrossCouplingCompensationmustbeinvokedtoassurethatthedesiredPhaseandMagnitudevaluesareachievedperthetestspecification.Spectral Dynamics has developed an Optimal Square Control capability which has been shown to controldynamic6DOF systems,whereother control strategies fail todo so.Thispaperdescribes theuseofauniqueSquareMatrixformulation,whichtogetherwithPatentedAdaptiveControl,createsaworkingcontrolsolutionforvirtuallyany8shaker6DOFconfiguration.MULTIAXISEXCITATIONMOREREALISTICVIBRATIONTESTINGMr.WayneTustin,EquipmentReliabilityInstituteIll observe that realworld vibratory motions are multiaxis. We can confirm this by observing signals frommultiaxisaccelerometersaboardour land,seaandairvehicles. Formanyyears,however,vibration testinghasbeenoneaxisatatime,requiringthreefixtures,threevibrationtests.Thispaperwilldiscussandpraiserelativelylow frequencymultiaxisvibratingplatforms (drivenbymultipleelectrohydraulic (servohydraulic) shakers,whichhave longbeenused forautomotiveand seismic testing. A fewUSmilitary installationshaveatgreatexpensecombinedthreeormoreexistinghigherfrequencysingleaxiselectrodynamicshakerstospeed(onetestinsteadofthree)and improvevibration testing. Theauthorhopes toknowbyNovemberwhether JapaneseandChinesemilitaryforcesrequiresimultaneousmultiaxisshaking.Wewillseethattheirshakermanufacturersoffermultiaxiselectrodynamicshakersystems.CONTEMPORARYMULTIAXISTESTSYSTEMS:APPLICATIONS,PERFORMANCEANDLIMITATIONSMr.CurtNelson,TeamCorporationMultiaxisexcitation,orgeneratingmotion inmultipledegreesof freedom (MDoF) simultaneously, isgenerallyagreedtorepresenttruedynamicenvironmentalloadingforafieldedcomponent.Whiletheautomotiveindustryhas depended upon road load replication for improving product quality for a number of years, interest inreplicatingMDoF inDoD laboratories is currently gaining considerable traction, evidenced by the inclusion ofMethod 527 inMIL STD 810(g) and the pending issue of IESTRPDTE022.1Multi Shaker Test and Control. Anumberoftestsystemswith3or6DoFhavebeenproveneffectiveandlessonslearnedfromthesesystemsshouldbeincorporatedintofuturedesigns.Thispresentationwillprovideanoverviewofcommerciallyavailablesystems,includingMASTtables,StewartPlatforms,theCUBE,andrepresentational3DoFsystemsutilizingelectrodynamicshakers.Theperformanceenvelopofeachsystemandtheirperformancelimitationswillbedefined.Mechanicalconsiderations, i.e.movingmass, system stiffness,moment restraint, etc.will be discussed and their resultingimpactonsystemperformance.Asummaryofsystemadvantagesanddisadvantagesservestocreateatemplateofdesirablecharacteristicsforimplementationintonewdesigns.BRINGINGTRUEBROADBANDFIELDVIBRATIONENVIRONMENTSINTOTHELABMr.CurtNelson,TeamCorporationCommerciallyavailablevibrationtestsystemsabletoreproduceandaccuratelycontrolmorethanasingleaxisofexcitationareconstrainedbyalimitedfrequencybandandexcessivemovingmass.Consequently,theiruseinDoDtestfacilitiesislimitedtoaselectnumberoftestprofilesfoundinMILSTDdocumentsand/ortoplatformspecifictestswhere the frequencybandof interest isquitenarrow. This constrainthasnowbeenaddressedwith theintroductionofanewsystembaseduponmultipleelectrodynamicshakershydrostaticallycoupledtothespecimenmountingtable.Thissystem,calledtheTENSOR,hasbeendesigned,built,andtestedbyTeamCorporationandisnowoperationalattwosites intheUSA.Thispresentationwilldiscussthedesignindetail,withanemphasison

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mechanicalsolutionswhichincreasedthefrequencyband,reducedmovingmassandprovidedmultiplepointsofcontrolauthorityforimprovedresponse.COMPARATIVERESULTSOFSINGLEAXISVIBRATIONVS.MULTIAXISMr.ChrisPeterson,H&HEnvironmentalSystems,Inc.Anexperimentwassetupincluding7testsofsimilarproducts.Eachsingleaxiswasused,thenthethreesetsofdualaxes, thenall threeaxesatonce. Thispaper is toshow thecomparativeresults. The testingwasdoneatTeamandsothismayfitinwellwiththeotherpresentationsbyTeam.STRESSBASEDCOMPARISONSBETWEENSINGLE&MULTIPLEDEGREEOFFREEDOMVIBRATIONMr.WilliamBarber,USArmyRedstoneTestCenterDr.MichaelHale,USArmyRedstoneTestCenterVibration specification development (VSD) procedures historically employed to establish reference criteria forsingledegreeoffreedom (SDOF) laboratoryvibrationtestingaregenerallyconservative innature. Manyfactorscontributetothisconservativeapproachincludinglimitedvehiclesassociatedwiththefielddatacollection,limitedmaneuversfromwhichdatawasacquired,uncertainties intheactualmissionscenario,and lackofcoupled loadvectors inaSDOF laboratorysetting, tonamea few. In recentyears therehasbeenan increasedutilizationofmultiple degreeoffreedom (MDOF) excitation systems across thedynamic test community. Unfortunately, inmanyinstancesMDOFspecificreferencecriteriahavenotbeenestablishedandusersdefaulttotheuseofSDOFautospectrum (ASD) referencesandassume the coherence characteristicsof the cross spectraldensities tobeuncorrelated.ConcernsexistthatthispracticehasthepotentialtoyieldahighlyconservativeMDOFtestresultingfromthecumulativeeffectsofconservatism.ThispaperinvestigatesthestressresponseofafiniteelementmodelbasedonbothSDOFandMDOFexcitationwithvariationsinmagnitudeandcoherence.Themodelisadjustabletoallow investigationof the responsewhen structuralmodes areeither coupledoruncoupledacrossmechanicalDOFs.Resultsofthemodelbasedanalysiswillbepresentedanddiscussed.

MODELING&SIMULATIONOFUNDERWATERSHOCKAUTOMATEDSHIPSHOCKM&SSOFTWARETOOLINTEGRATION;THENEWCOMMONSTRUCTURALMODEL(CSM)GUI:RAPIDEARLYSTAGEDESIGNTOOLDr.RussMiller,AlionScienceandTechnologyMr.PaulLara,NSWCCarderockMr.BrianRich,AlionScienceandTechnologyDr.E.ThomasMoyer,Jr.,NSWCCarderockOneoftheprimarychallengesrecognizedbyNAVSEA,NSWCCDandONRconcernstheabilitytoobtainarapidandaccurate technical assessment of an early stage ship design as required for decision making purposes. Forexample, current ship designs have demonstrated that approximately 80 percent of the shockmodeling andsimulation(M&S)effortisspentonmodelgenerationandonly20percentofthateffortisspentonactualdesignassessment. Asa result, theNavyandONRsetagoal to reduce theamountofeffortdevoted togeneratingawholeshiptransientanalysis(WSTA)finiteelementmodelbyanorderofmagnitude.Inordertoanswerthischallenge,theM&Steamisdefininganddemonstratingthecurrentstateoftheartforshipshock model generation for the ONR Swampworks, Full Ship Shock Trial (FSST) alternative and CREATE(ComputationalResearchandEngineeringAcquisitionToolsandEnvironments)programs.Inpreviouspapers,anautomatedapproachwithadvancedfeatures,developedbytheONRM&Steam,waspresentedthat iscurrentlyrecognizedbyONRandtheNavyasabletomeetthegoalsandrequirementsoftheSwampworksprogram.In this paper, an advancedGraphicalUser Interface (GUI) for CSM is presented togetherwith additional newfeaturesandmodelingcapabilities. ThisGUIdevelopsanearlydesigntemplate for thevessel,generated ina

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rapidfashionwithminimalinput.Thenutilizingoptimizedinputs,allowstheusertoquicklyupdatetheirmodeltohigherfidelitydetailedstructuralfeatures.EFFECTOFABUBBLYLAYERONANINCOMINGPRESSUREWAVEMr.ArvindJayaprakash,DynaflowInc.Mr.SowmitraSingh,DynaflowInc.Dr.ChaoTsungHsiao,DynaflowInc.Dr.GeorgesChahine,DynaflowInc.ThegenerationofstrongpressureandexpansionwavesduringaSpallationNeutronSourcefacilityoperationcanlead tocavitationandsignificanterosionof thevesselwallcontaining the liquidmercury.Basedonpreliminarynumericalandexperimentalwork,mitigationstrategiessuchasinjectingmicrosizedgasbubblesorcreatingagaslayeratthetargetwallofthemercuryloopcouldabsorbandreflecttheshockwavesandprotectthewallsfromcavitationerosion.Inthiswork,theeffectsofdispersedmicrobubblesonasteeppressurewaveanditsattenuationarenumericallyinvestigatedusinganEulerequation solver. In the simulations, themercuryargonmixturewasmodeledusingeither ahomogenousmixturemodelordirectnumerical simulations involvingdiscretedeformingbubbles. Toreducecomputationalcostsa1Dconfigurationisusedandthebubblesareassumeddistributedinlayersandtheinitialpressureprofileisselectedsimilartothatofaonedimensionalshocktubeproblem.Thedependenceofpressurewaveattenuationeffectonthebubbleradii,thevoidfraction,andthebubbly layerthicknesswerestudied.Inaddition,theapplicabilityoftheassumptionofhomogeneousmediawasinvestigated.Inthecaseofdiscretebubblymedia,thepressuremitigationcanbeseenasduetowavesreflectinganddispersingbetweentheinterbubbleregions,withtheenergyabsorbedbybubblevolumeoscillationsandreradiation.Theseeffectsaresmoothedoutinahomogeneousmixturemedia,whicheasilyshowsthatthesoundspeedisafunctionofvoidfractionandresultinthephasedelay.Layerthicknessandsmallbubblesizescanalsobeseenashavingastrong effect on the attenuationwith enhanced attenuation as the bubble size is reduced for the same voidfraction.PARAMETERIZATIONOFTHEPRESSUREWAVEEMITTEDBYHYDROSTATICIMPLOSIONOFSUBMERGEDCYLINDERSDr.JeffreyCipolla,WeidlingerAssociatesDr.MichaelD.Shields,WeidlingerAssociatesMr.PawelWoelke,WeidlingerAssociatesDr.NajibN.Abboud,WeidlingerAssociatesTherapidinwardcollapseassociatedwithhydrostaticbucklingofsubmergedcylindersresultsinanoutwardlyemittedhighpressurewaveinthewaterthatmaybedamagingtonearbystructures.Inthecurrentstateofpractice,themagnitudeofthispressureanditsassociatedimpulsearedifficulttoobtainbecauseeitherexperimentsorcomputationallycostlyhighfidelitycouplefluidstructurecalculationsarerequired.Forthisreason,thereisadesiretodevelopafastrunningutilitycapableofpredictingthepressurewaveemittedfromimplosionfromthegivencylindergeometryandhydrostaticpressure.Asafirststeptowardthisend,aparameterizationoftheimplosionproducedpressurewavehasbeendevelopedandwillbepresented.USEOFANEURALNETFORRESPONSESURFACEBASEDPREDICTIONOFTHEPRESSUREWAVEEMITTEDBYHYDROSTATIC IMPLOSIONOFSUBMERGEDCYLINDERSDr.JeffreyCipolla,WeidlingerAssociatesDr.MichaelD.Shields,WeidlingerAssociatesMr.PawelWoelke,WeidlingerAssociatesDr.NajibN.Abboud,WeidlingerAssociatesTherapidinwardcollapseassociatedwithhydrostaticbucklingofsubmergedcylindersresultsinanoutwardlyemittedhighpressurewaveinthewaterthatmaybedamagingtonearbystructures.Inthecurrentstateof

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practice,themagnitudeofthispressureanditsassociatedimpulsearedifficulttoobtainbecauseeitherexperimentsorcomputationallycostlyhighfidelitycouplefluidstructurecalculationsarerequired.Forthisreason,thereisadesiretodevelopafastrunningutilitycapableofpredictingthepressurewaveemittedfromimplosionfromthegivencylindergeometryandhydrostaticpressure.Towardthisend,aparameterizationoftheimplosionproducedpressurewavehasbeendeveloped.Thisparameterizationisusedtocharacterizepressurehistoriesspanningalargenumberofstructuralconfigurationsandhydrostaticpressures.Thesedataarethenusedtotrainaneuralnetforgenerationofaresponsesurfaceforrapidpressurewavepredictionforagivencylindergeometryandhydrostaticpressure.

BLASTMEASUREMENT&ANALYSISPREDICTIONOFLANDMINEBLASTEFFECTSWITHCONWEPANDSPHINLSDYNADr.XudongXin,QinetiQNorthAmericaDr.AbdullatifZaouk,QinetiQNorthAmericaDr.BasantParida,QinetiQNorthAmericaDynamic loading scenario of airblast, fragmentation and soilejecta produced by landmine detonation arepersistent threats to lightweightmilitaryvehicles. In thepastdecade, considerableeffortshavebeenmadeondesigning effective landmine blast mitigation devices for military vehicles, and also on developing accuratepredictionmethods for landmine blast loading effects in helping such designs. QinetiQ North America (QNA)recently invented a new type of blastmitigation deviceswhich can greatly reduce the shock acceleration ofvehicles and increase the survivability of occupants in a landmine explosion event. This paper discusses aneffectiveapproachforpredictingblastloadingeffectsonvehicleduetolandminedetonation.Toaccuratelypredictalandmineblastloadingscenario,twomajormomentumcontributionstransferredfromthemineblasttovehiclearecalculatedinseparateways.TheairblastoverpressureloadingiscalculatedbyCONWEPfunctionembeddedinLSDYNA.Momentum imparted tovehiclebysoilejecta isexplicitlymodeledwithSPHmethod inLSDYNA.Thisapproachhasnotonlyreproducedprevioustestresults,butalsomadereliablepretestpredictionsandimprovedthe designing efficiency ofQNA blast attenuators. The comparisons between test data and numerical analysisresultswillbepresented to show theproposedapproach is costeffectiveandyetaccurate fora simple targetgeometryinpredictinglandmineblasteffectsonmilitaryvehicles.MODELINGDETONATIONSTOINFORMBLASTRESISTANTDESIGNOFBUILDINGSProfessorAndrewWhittaker,UniversityatBuffaloProfessorAmjadAref,UniversityatBuffaloMr.PushkarajSherkar,ThorntonTomasettiBlastresistantdesignhasbeentraditionallyperformedusingpressureandimpulseloadingsderivedfromempiricaldesign chartsprovided in technicalmanuals suchas theUFC3340.Thedesign chartsarebasedon regressionanalysisoftestdataforsphericalburstsandhemisphericalbursts.Fornonidealizedscenariosnumericalsolutionscanbeused if themathematicalmodelsarerobust.Acomprehensivestudyofdifferentmodelingstrategies fordetonationsavailableinthreewidelyusedcodes(LSDYNA,Air3DandAUTODYN)isperformed.Sampleresultsarecomparedwith those computedusing the empirical curvesofUFC3340.Recommendations formodeling andanalysisofnearfielddetonationsareprovided.IMPLICATIONSOFEXPLOSIVELYACCELERATINGTHINFLYERPLATESINTRANSIENTREGIMESOFEXPLOSIVESYSTEMSMr.MarcusChavez,SandiaNationalLaboratoriesApplicationofthetraditionalGurneymodelsinthetransientregimesofexplosivesystemspresentscomplicationswithdeterminationoftheterminalvelocityachievedbyametalflyerplatedrivenbyanexplosive.Aninvestigationwasconductedtoprobethephenomenainthespraydepositedandlightsensitiveexplosive,silveracetylidesilvernitrate, used to accelerate thin aluminum flyer plates in both laboratory experiments and in CTH hydrocodesimulations. Flyerplatevelocity trackingvia laser interferometrypointsout that therearedistinctacceleration

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phasesduringthefirstfewmicrosecondsoftravel. Specific impulsemeasurementscomparedtomeasuredflyerplatevelocitytracesindicatethatexplosiveoutputvariationdoesnotsignificantlyaffectthepresenceoflatetimeaccelerations,onlyachievedvelocitiesareaffected.Bulkdensitymeasurementsshowalinearlyincreasingdensityasmore explosive is deposited, but the variation at each spray deposition obscures the relation to transientprocesses. However, thevariationofspraydepositedmaterialaredocumented in thispaperandsupports thatdeflagrationtodetonationtransitionphenomenaareintroducingscatterintotheterminalvelocityofaflyerplate.CTH simulations showhowaType Ideflagrationtodetonation transitioncan increase themaximum flyerplatevelocitybyapproximately3%ascomparedtoGurneymodelsundercertainassumptionsandtimeframes.Underotherassumptionsandthesametimeframe,themaximumvelocitycanincrease15%relativetonominal.ATypeIIdeflagrationtodetonationtransition,orcommonlyreferredtoasthedeflagrationto localizedthermalexplosiondetonationtransition,candecreasetheoutputby9%ofnominalwhileunderonesetofassumptionsorincreaseupto15%givendifferentassumptions.EXPERIMENTALRESISTANCEFUNCTIONDEVELOPMENTUSINGLOADTREETESTINGFORINCORPORATIONINTOSINGLEDEGREEOFFREEDOMDYNAMICBLASTANALYSESMr.CaseyOLaughlin,JacobsTechnologyDr.EricWilliamson,UniversityofTexasatAustinMr.CharlesNewberry,JacobsTechnologyToquantifyadesignagainstablastload,adesignengineercanelecttoperformasingledegreeoffreedom(SDOF)dynamic analysis.One issue that is important to the SDOF analysisprocedure isdefining the entire resistancefunctionofacomponent.Analyticaldevelopmentoftheresistancefunctionformembersthatmakeupstructuralcomponents can be obtained through fundamental structural mechanics. Because an engineer must makeassumptionsregardingthemodeshapesofcomponentsastheyrespondelasticallyandplastically,theanalyticalapproachcanbecomechallenging.Thispaperpresentsanalternativeapproachtodevelopingresistancefunctionsusingaloadtreetestingdevicetoexperimentallyobtaintheresponseofacomponent.Datagatheredfromsuchtests can thenbe incorporated into SDOFdesignprocedures.Accuracyof the SDOFprocedure is compared toFiniteElementAnalyses (FEA)anddataobtained from largescaleblasttests.Attendeesofthispresentationwillgain insight intohowa loadtreetestingdeviceoperates,howresistance functionsaredeveloped,andhowthisinformation isusedtoconductdynamicresponsecalculationsofblast loadedstructures. Information included inthispresentationwillbeofinteresttopractitioners,designers,andresearchengineers.BLASTOVERPRESSUREENVIRONMENTSFOREVALUATINGSOLDIERPROTECTIVEEQUIPMENTMr.W.ScottWalton,ATSSMr.BrandonHepner,USArmyAberdeenTestCenterMr.MichaelMaffeo,USArmyAberdeenTestCenterAvarietyofdifferentblastoverpressureenvironmentsareusedforresearchofvarioussoldierprotectivedevices.Theseenvironmentsinclude:A.AhighpressureshocktubeB.FreefielddetonationofbareexplosivechargesC.DetonationofexplosivechargesinsidevariousenclosuresUnlikeclassicalshocktubes,whichuselongdriversectionstoproduceflattoppedpressurevs.timewaveforms,thenewATChighpressureshocktubeproducesanexponentiallydecayingpressurevs.timewaveform(similartothe Friedlander waveform found in free field BOP events). These three different experimental blastenvironmentsarediscussedandcomparedintermsofcost,convenience,severity,shockwavecharacteristics,andsimilaritytocombatenvironments.Avarietyofdifferentcriteriaareused tocharacterize the severityofeachenvironment. Examplesofdifferentevaluationcriteriainclude:A.MILSTD1474D,DepartmentofDefenseDesignCriteria(NoiseLimits)forauditoryevaluationB.TheArmyendorsed Injury8.3code,when it ispossibletouseaBlastTestDevice (oraModifiedBlastTestDevice)inthetestenvironment.

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C.ThePulmonaryInjuryRiskAssessmentcurvesdevelopedattheUniversityofVirginiain2008forsituationwhereaBTDorMBTDcannotbeusedinthetestenvironment.The three different evaluation criteria are also discussed and compared. For historical purposes, a forthevaluationtechnique(theBowenCurves,developed in1968) isalsodiscussed. Atestdeviceforevaluationofbodyarmorandpersonalprotectivematerialsforresearchinattenuationofblastloadingseverityisdiscussed.ACOMPARATIVEANALYSISOFAIRBLASTLOADPREDICTIONMODELSMr.WililamLeBoeuf,ABSConsultingMr.GregoryKnight,ABSConsultingNumericalmodelingofstructuralsystemssubjectedtoblastloadinghasbecomemorecommonanduseofmorecomplex and higher fidelitymethods such as hydrocodes and CFD has increased in the past 1015 years. Ascomputingpowerandsoftwarecapabilitieshavegrown,blastloadscanbecalculatedandappliedtostructuresinvarying degrees of complexity. Some of the major issues with predictions using complex codes, such asfluid/structure interaction modeling in hydrocodes, are the amount of time, the requisite computer powerrequired to run largemodels,and theadditional specific knowledgeof thephysicalmethodsand software theanalystmusthavetogeneratereliablesolutions;nottomentionuncertaintiesinthedatageneratedbythecodesandhowthatinformationcomparestoactualtestdata.The intentofthispaper istocomparevariousnumericalanalysismethodsforblast loadpredictionandevaluatethedifferencesbetween thesemethodsandcompare tosimplerempiricalbasedapproachesaswellasasetofblastloadtestdatacollectedduringafullscaletestprogramconductedbyABSConsultingin2005.ThetestingwasperformedusingANFOastheexplosivematerial.One of the key factors in the comparisonwill be to evaluate the definition of the equation of state for theexplosiveinthenumericalmodels.SinceANFOisacompositenonidealexplosivethematerialconversionduringthedetonationprocess requires accuratedefinition. Theparameters for EOSdefinitions in eachmodelwillbedefined.Thecomparisonwillalsoidentifykeyaspectsofthemodelingefforttoachievetheclosestapproximationtothetestdataincludingmeshrefinementandothermaterialmodeldefinitions.Resultsfromthemodelingwillbecomparedtobothtestdataandmoreconventionalloadpredictionmethodsusingmethodssuchasscalingcurves,theKingeryBulmashequations,andConWep.

DEDICATEDSESSION:UNDERWATEREXPLOSIONBUBBLESIMULATIONS

ASSESSMENTOFMULTICYCLEUNDERWATEREXPLOSIONBUBBLESIMULATIONCAPABILITIESINDYSMASMr.GregoryHarris,NSWCIndianHeadDivisionMr.AyodejiOjofeitimi,NSWCIndianHeadDivisionThe simulation of underwater explosion bubble dynamics is a critical capability of hydrocodes used for navalapplications.Inthisstudy,theabilityoftheDYSMASEulersolver,Gemini,tosimulatemultiplebubbleoscillationsisassessed.Geminiperformanceisbasedoncorrelationsofbubbleradii,bubbleperiods,migrationdistances,andbubbleenergiesascomparedtoempiricalequationsandunderwaterexplosiontestdata.Casesanalyzed includetwolargechargeswithrelativelyshallowgeometriestypicaloftorpedoandminedetonationsnearsurfaceships.Acaserepresentativeofdeepexplosionsisalsoconsidered.VALIDATION OF DYSMAS FOR CLOSEIN SHOCK AND BUBBLE JET DAMAGE TEST AGAINST THE EXTURKU FAST ATTACK CRAFTMr.KennethKiddy,NSWCIndianHeadDivisionMr.GregoryHarris,NSWCIndianHeadDivisionAspartofaFinlandUSGermanyMOAonaluminumsurfacecombatantdesign,aseriesofweaponeffectstestswereconductedagainstadecommissionedFinnishFastAttackCraft (FAC),theexTurku.Onetestsubjectedthe

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hull toclosein shockandbubble jet loading.Data from this testwasused tovalidate theDYSMAShydrocode,thereby fillinga criticalgap in theUNDEXdatabase.Detailsof thedata collectedand correlationwithDYSMASsimulationswillbepresented.DYSMASSIMULATIONOFUNDERKEELBUBBLEJETATTACKMr.KennethKiddy,NSWCIndianHeadDivisionMr.GregoryHarris,NSWCIndianHeadDivisionThe DYSMAS hydrocode was used to simulate the response of a ship to the effects of a large noncontactunderwaterexplosion(UNDEX)belowthehull.OfprimaryinterestwerethecombinedeffectsoftheUNDEXshockwave and bubble, particularly the damage due to the bubble jet. The effects of severe hull girderwhippingresponseandlocalizedbubblejetloadingareillustratedbythesimulation.ACCURATEANDEFFICIENTPHYSICSBASEDSOFTWARETOMODELAIRGUNSDr.GeorgesChahine,Dynaflow,Inc.Mr.ChaoTsungHsiao,Dynaflow,Inc.Aphysicsbasedmodel,PHANTOMCLOUDC,wasdeveloped tomodelefficiently and accurately airgunpressuresignals and loadings on nearby structures. Themodel accounts for key airgun geometrical parameters,whichaffectairrelease intothebubblesejected intothe liquid, interactionbetweenthereleasedbubbles,gravity,andanynearbystructures. Thismultibubbledynamicsoftwarehasbeenshowntomatchexperimentallymeasuredpressuresignalsand iscapable,whencoupledwithastructurescode,ofcorrectlyrecoveringtargetresponsetothe loading. Since themodel isphysicsbased itallowsverysimplyaccount forgunorientation, typeof thegasloadedinthegun,andinterguninteractions.PROCESSFORACCEPTABILITYOFSHOCKISOLATEDDECKMODULE(IDM)SHOCKENVIRONMENTFORTHEINSTALLATIONOFCOMMERCIALOFFTHESHELF(COTS)EQUIPMENTONSUBMARINESMs.RebeccaD.Grisso,NSWCCarderockTo facilitate the use of COTS equipment, while meeting ship hardness requirements, the use of an IDM isemployed.IDMsarespecificallydesignedtomitigateinputloadsandproduceanenvironmentseenbyequipmentto a demonstrated level of equipment survivability. Previous analysis of computationalmodels and test dataconcludedthataknowndeckproducedanacceptableenvironmentforequipmentsurvival.Theprocesspresentedherein is themethod bywhich a new IDM can be shown to provide a nomoresevere environment than theacceptedbaseline. Demonstrationofanenvironmentbeingnomoreseverecanbeachievedbymeetingoneoftwocriteria:1)agroupbaseddirectspectralcomparisonor2)acumulativedistributionfunctionanalysis.STUDIESINSMALLCHARGEUNDEXSHOTSELECTIONFORSUBMARINEANALYSESMs.RebeccaD.Grisso,NSWCCarderockMs.CaroleOverman,NSWCCarderockGivenan infinitesetofUNDEXchargeweightsandgeometriespotentiallyusedasanalysisscenariosforshowingsubmarine equipment hardness, a method is needed to choose a subset for demonstration of submarinesurvivability.Thisstudyproceededintwosteps:first,arangeofsmall,bubbleproducingchargeswasconsideredoverarangeofreasonabledepthswiththebubblecodeDFMigrate. Thisresulted inapossiblerangeofbubblefrequencies,impulses,andpressures.Second,thetoolAnalysis,DesignandQualificationUNDEXEventSelection(ADQUES)wasusedtoranktheseverityofthe loadings,asseenby internallymountedequipment. PreliminarystudieswithADQUESweredonetodeterminesensitivitiesandrefinespecifiedparameters.LaterADQUESstudiesfocusedontheseverityrankingofattackscenarios.

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CREWINJURYSTUDIESOVERVIEWOFTHEUNDEXINDUCEDINJURYTESTSERIESMs.KristaHarris,NAVSEACarderockDr.ThomasMoyer,NAVSEACarderockMr.ThomasBrodrick,NAVSEACarderockTheUNDEXInducedInjuryTestSeriesfocusedontheHYBRIDIIIresponsetoanunderwaterexplosionwhileaboardtheFloatingShockPlatform(FSP).Thistestutilizedthree50thpercentileHybridIIIanthropomorphictestdevicessurrounded by representative shipboard structure serving as blunt impact surfaces. Six UNDEX shots wereperformedwithvaryingchargestandoffandHybridIIIorientationtoinducearangeofshockseveritiesandinjuryresponses.Overninetysensorswereusedtomeasuretheforces,moments,andaccelerationstransferredthroughtheHybridIIIbody.UNDEXINDUCEDINJURYTESTSERIES:EVALUATIONOFANTHROPOMORPHICTESTDEVICEDr.TimothyWalilko,NAVSEACarderockMs.KristaHarris,NAVSEACarderockNoabstractprovided.ANALGORITHMFORPREDICTINGCREWINJURIES/CASUALTIESDUETOAIREXLOADINGMs.KristaHarris,NAVSEACarderockDr.ThomasMoyer,NAVSEACarderockMr.ThomasBrodrick,NAVSEACarderockAninternalorexternalweapondetonationcancausesignificantinjuriestoshipboardcrew.Thispaperexaminescrew injuriesresulting fromAirExplosions (AIREX) invariousshipboardcompartments. Awiderangeof loadingscenariosand injurymechanismsareconsideredfortheblunt impactscrewmembersencounterwithshipboardstructureanddebris.DetailedModelingandSimulation(M&S)effortswereperformedtoserveasthefoundationfor the rapid prediction algorithm. This algorithm, similar to the UNDEX Blunt Trauma and Inertial LoadingAlgorithmsdeveloped in thepast,providesa stochastic injury response toolused forvulnerabilityassessmentsacrossalargethreatspace.CONTROLLING BLAST EFFECTS USING NOVEL COMBINATIONS OF POLYMERS, MESHES AND HIGHLY VOIDED FIBERREINFORCEDCOMPOSITESMs.AlyssaLittlestone,NavalSurfaceWarfareCenterMr.PhilipDudt,NavalSurfaceWarfareCenterExposuretoblastwavescanproducesevereinjuriestothelungs,gastrointestinaltract,andtraumaticbraininjury(TBI).Blastwavecontent,particularlyinthe1000to3000Hzrangehasbeedfoundtobeespeciallydamagingtothe lungsorpossiblyonanaxonal level,affect thebrainaswell. Ithasbeenestablished that it ispossible tomitigate blast effects through the combination of high impedance (stiff)materials, backed by lowimpedancematerials. High impedance effects can bemagnified through incorporation of highly ratesensitive polymers.Further,meshesandbafflescanpromotefilteringeffectsbypromoting intrareflectionsand interfernces. Mesheffectscanbepromotedthroughopen fibercompositeweaves,conventionalmetal foils,andperforatedplates.Combining these attributes in a hybrid architecture ia an important challenge for developing blast protectingstructureandcombathelmetsforprotectingthewarfighter.

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OUTOFPOSITIONLOADINGRESPONSEOFTHEHIII&MILLXLOWERLEGSTOSIMULATEDBLASTEFFECTSMr.JeffreyNesta,ArmyResearchLaboratoryMr.AmiFrydman,ArmyResearchLaboratoryCombatvehiclepersonnelaresusceptibletolowerleginjuriescausedbyblast