2011 Vol. 31, No. 6
Display Method:
2011, 31(6): 561-566.
doi: 10.11883/1001-1455(2011)06-0561-06
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Abstract:
Abstract:Arotor-bearingsystemunderbase-transferredshockexcitationwasestablishedbyapplying theGalerkinfiniteelementmodeltosimulatetheshipboardrotatingmachinerysubjectedtounderwaternon- contactexplosion.Basedonthe Newton'stheorem,moment-of-momentum theorem and Timoshenkobeamtheory,thedynamicdifferentialequationsofthissystemwerederivedbysyntheticallyconsideringtherotatinginertia, shearforce,gyroscopiceffect,axialforce,axialtorqueandoil filmforce.Thedynamicdifferentialequationsweresolvedbyusingthefinitedifferencemethodsin thetimedomainandthefiniteelementmethodinthespacedomain,respectively.Andthetime-varyingshockresponsesofthissystemwereobtained. Theaccuracyoftheproposedmodelwasverified. Finally,anapplicationexamplewasgiventoanalyzetheinfluencesofthegyroscopiceffectandsteady workloadingontheshockresponsesofthissystem.Investigatedresultsshowthattheaccuracyofthe proposedmodelingandcomputationmethodcanmeettheengineeringrequirementandthegyroscopic effecthasanobviousinfluenceontheshockresponses;andthattheworkloadingcantoneupthesystemresponse, buttheoverallresponsewiththesteadyworkloadingbeingconsideredisdistinctfrom thesumofthesteadyresponseandtheshockresponsewithoutthesteadyworkloadingbeingconsidered.
Abstract:Arotor-bearingsystemunderbase-transferredshockexcitationwasestablishedbyapplying theGalerkinfiniteelementmodeltosimulatetheshipboardrotatingmachinerysubjectedtounderwaternon- contactexplosion.Basedonthe Newton'stheorem,moment-of-momentum theorem and Timoshenkobeamtheory,thedynamicdifferentialequationsofthissystemwerederivedbysyntheticallyconsideringtherotatinginertia, shearforce,gyroscopiceffect,axialforce,axialtorqueandoil filmforce.Thedynamicdifferentialequationsweresolvedbyusingthefinitedifferencemethodsin thetimedomainandthefiniteelementmethodinthespacedomain,respectively.Andthetime-varyingshockresponsesofthissystemwereobtained. Theaccuracyoftheproposedmodelwasverified. Finally,anapplicationexamplewasgiventoanalyzetheinfluencesofthegyroscopiceffectandsteady workloadingontheshockresponsesofthissystem.Investigatedresultsshowthattheaccuracyofthe proposedmodelingandcomputationmethodcanmeettheengineeringrequirementandthegyroscopic effecthasanobviousinfluenceontheshockresponses;andthattheworkloadingcantoneupthesystemresponse, buttheoverallresponsewiththesteadyworkloadingbeingconsideredisdistinctfrom thesumofthesteadyresponseandtheshockresponsewithoutthesteadyworkloadingbeingconsidered.
2011, 31(6): 567-572.
doi: 10.11883/1001-1455(2011)06-0567-06
Abstract:
Basedonthecontinuum medium mechanicstheoryoffiberreinforcedcompositematerials andtheviscoelastictheory,arate-dependentconstitutivemodelwasproposedforporcineham muscle. Themodelparametersweregainedbyfittingtheconstitutiveequationstothestress-straincurves whichwereobtainedinthepreviousSHPBandSHTBtests.Theresultsexhibitthattheproposed modelcandescribethedynamiccompressiveandtensilemechanicalpropertiesofporcineham muscle alongthefiberdirection.Theconsistencybetweenthemodelandtheexperimentshowsthatthestudy cangiveatheoryfoundationforthenumericalsimulationofthesecurityprotectionsystems.
Basedonthecontinuum medium mechanicstheoryoffiberreinforcedcompositematerials andtheviscoelastictheory,arate-dependentconstitutivemodelwasproposedforporcineham muscle. Themodelparametersweregainedbyfittingtheconstitutiveequationstothestress-straincurves whichwereobtainedinthepreviousSHPBandSHTBtests.Theresultsexhibitthattheproposed modelcandescribethedynamiccompressiveandtensilemechanicalpropertiesofporcineham muscle alongthefiberdirection.Theconsistencybetweenthemodelandtheexperimentshowsthatthestudy cangiveatheoryfoundationforthenumericalsimulationofthesecurityprotectionsystems.
2011, 31(6): 573-578.
doi: 10.11883/1001-1455(2011)06-0573-06
Abstract:
Amulti-pointignitionsystemwithanelectricigniterwasdesignedandexperimentalinvestigationswerecarriedoutbyusingthisanalogueignitiondevic tosolvethechargeproblemsinthe powderchamberswiththeover3mlength.Thecorrespondingmathematicalandphysicalmodelswere establishedtodescribethemulti-pointignitionprocessinthisanalogueignitiondevice.The Mac- Cormackdifferenceequationwasusedtoobtainthenumericalsolutionsasfollows:Thepressuredistributionandvoidratioandsolidandgasvelocities. Andthemulti-pointignitionprocesswasanalyzed. Thecalculatedresultsareconsistentwiththeexperimentalonesandthealgorithmiseffective.
Amulti-pointignitionsystemwithanelectricigniterwasdesignedandexperimentalinvestigationswerecarriedoutbyusingthisanalogueignitiondevic tosolvethechargeproblemsinthe powderchamberswiththeover3mlength.Thecorrespondingmathematicalandphysicalmodelswere establishedtodescribethemulti-pointignitionprocessinthisanalogueignitiondevice.The Mac- Cormackdifferenceequationwasusedtoobtainthenumericalsolutionsasfollows:Thepressuredistributionandvoidratioandsolidandgasvelocities. Andthemulti-pointignitionprocesswasanalyzed. Thecalculatedresultsareconsistentwiththeexperimentalonesandthealgorithmiseffective.
2011, 31(6): 579-584.
doi: 10.11883/1001-1455(2011)06-0579-06
Abstract:
Water-entryexperimentswereconductedinthevelocityrange35~160m/sfortheprojectilesofthethreedifferentgeometriesincludingflatnose, truncated-ogivalnoseandogivalnose.A digitalhigh-speedcamerawasusedtorecordthedetailedprocessesofwaterentryandcavityexpansion andobtainthehydro-ballistictrajectoriesandcavityshapesintheearlystagesofwaterentryforthe projectilesofthethreedifferentgeometries.Andtheeffectsofthenoseshapesonthehydro-ballistic stabilitieswerecomparedamongtheprojectilesofthethreedifferentgeometries.Comparisonsindicatethattheflatnoseprojectilehasgoodhydro- ballisticstabilityinthewater,thetruncated-ogival noseprojectilewilldeflectinthelatestageofwaterentrywhichisresultedfromthedeflectingforce ontheprojectilenose,bycontrary,theogivalnoseprojectilewilldeflectintheearlystageofwater entrywhichhastheworststability.Byconsideringthecavitationnumberwasavelocity-dependent factor,amodifiedmathematicalmodelwasproposedtopredictthevelocityattenuationofcylindrical projectilesandacavitydimensionmodelwaspresentedbasedontheenergyconservation.Thecalculationsareingoodagreementwiththeexperimentalresults.
Water-entryexperimentswereconductedinthevelocityrange35~160m/sfortheprojectilesofthethreedifferentgeometriesincludingflatnose, truncated-ogivalnoseandogivalnose.A digitalhigh-speedcamerawasusedtorecordthedetailedprocessesofwaterentryandcavityexpansion andobtainthehydro-ballistictrajectoriesandcavityshapesintheearlystagesofwaterentryforthe projectilesofthethreedifferentgeometries.Andtheeffectsofthenoseshapesonthehydro-ballistic stabilitieswerecomparedamongtheprojectilesofthethreedifferentgeometries.Comparisonsindicatethattheflatnoseprojectilehasgoodhydro- ballisticstabilityinthewater,thetruncated-ogival noseprojectilewilldeflectinthelatestageofwaterentrywhichisresultedfromthedeflectingforce ontheprojectilenose,bycontrary,theogivalnoseprojectilewilldeflectintheearlystageofwater entrywhichhastheworststability.Byconsideringthecavitationnumberwasavelocity-dependent factor,amodifiedmathematicalmodelwasproposedtopredictthevelocityattenuationofcylindrical projectilesandacavitydimensionmodelwaspresentedbasedontheenergyconservation.Thecalculationsareingoodagreementwiththeexperimentalresults.
2011, 31(6): 585-591.
doi: 10.11883/1001-1455(2011)06-0585-07
Abstract:
Afixed-cavityangulardispersionFabry-Perotvelocityinterferometerwasdevelopedbyapplyingasolidetalontorealizethatthisinterferometer'sstructurewascompact, theinterferencefringesobtainedbyitwereadjustment- freeanditsfringeconstantcouldbeeasilyandaccuratelycalibrated. Thisinterferometerwasusedintheexperimentwithanelectricguntoacceleratea10-mm-diameter, 0.25-mm-thickMylarflyer.Theinterferometergavegoodresultsevenwhentheintensityoflight reflectedfromthetargetchanged100times.Themeasurementaccuracyofthesystem wasanalyzed bytakingaccountofetalonthicknesserror,unparalleletalonsurfaces,fringebroadening,imageaberration, andsoon.Andthevelocityresolutionandthetemporalresolutionwerealsoanalyzed.
Afixed-cavityangulardispersionFabry-Perotvelocityinterferometerwasdevelopedbyapplyingasolidetalontorealizethatthisinterferometer'sstructurewascompact, theinterferencefringesobtainedbyitwereadjustment- freeanditsfringeconstantcouldbeeasilyandaccuratelycalibrated. Thisinterferometerwasusedintheexperimentwithanelectricguntoacceleratea10-mm-diameter, 0.25-mm-thickMylarflyer.Theinterferometergavegoodresultsevenwhentheintensityoflight reflectedfromthetargetchanged100times.Themeasurementaccuracyofthesystem wasanalyzed bytakingaccountofetalonthicknesserror,unparalleletalonsurfaces,fringebroadening,imageaberration, andsoon.Andthevelocityresolutionandthetemporalresolutionwerealsoanalyzed.
2011, 31(6): 592-599.
doi: 10.11883/1001-1455(2011)06-0592-08
Abstract:
Opticalmeasurementcomponentsweredesignedandmachinedtobeequippedintheconventionaldrop- weightsystem.Basedontheimproveddrop-weightsystem,theresponseprocessesofdifferent- massHMXparticlesimpactedbythedifferentfalling-heightweightdropswererecordedbya high-speedcameraonthemicrosecondtimescale.Theprocessesconsistedofthefollowingphenomena: explosiveparticledeformation,melting,ignition,combustionandexplosion.Andaseriesofanalysiswerecarriedoutfortheinfluencesofdrop- weightfallingheightandexplosiveincompactness degreeonexplosiveparticledeformation,ignitiondurationandcombustionintensity.Investigatedresultsshowthatthehigherthefallingheightofthedropweight, thelongerthedurationoftheplastic deformation,theignitionoftheexplosiveinsteadoftheinjectionisapttooccur;thatthelowerfalling heightofthedropweighttendstoinducetheexplosivetointensivelyjetratherthanbeignited;that thehighertheincompactnessdegreeoftheexplosive,theshorterthedurationoftheplasticdeformation, multiplehotspotsareeasiertoformandcoalescewhichleadstohighcombustionprobability.
Opticalmeasurementcomponentsweredesignedandmachinedtobeequippedintheconventionaldrop- weightsystem.Basedontheimproveddrop-weightsystem,theresponseprocessesofdifferent- massHMXparticlesimpactedbythedifferentfalling-heightweightdropswererecordedbya high-speedcameraonthemicrosecondtimescale.Theprocessesconsistedofthefollowingphenomena: explosiveparticledeformation,melting,ignition,combustionandexplosion.Andaseriesofanalysiswerecarriedoutfortheinfluencesofdrop- weightfallingheightandexplosiveincompactness degreeonexplosiveparticledeformation,ignitiondurationandcombustionintensity.Investigatedresultsshowthatthehigherthefallingheightofthedropweight, thelongerthedurationoftheplastic deformation,theignitionoftheexplosiveinsteadoftheinjectionisapttooccur;thatthelowerfalling heightofthedropweighttendstoinducetheexplosivetointensivelyjetratherthanbeignited;that thehighertheincompactnessdegreeoftheexplosive,theshorterthedurationoftheplasticdeformation, multiplehotspotsareeasiertoformandcoalescewhichleadstohighcombustionprobability.
2011, 31(6): 600-605.
doi: 10.11883/1001-1455(2011)06-0600-06
Abstract:
Theone-dimensionalthermalshockwaveinacarbon-phenoliccompositewastakenforan exampletodiscusstheinfluencesofconstitutivemodelsonnumericallysimulatedresultsofX-ray thermalshock wavesincomposite materials.Thecorrespondingnumericalsimulationswereperformedbyadoptingthreedifferentconstitutivemodels. Thesimulatedresultsrevealthatthepeak stressacquiredbytheanisotropicdynamicelasto-plasticconstitutivemodelislower,itsattenuationis fasteranditisbeclosertotheexperimentalresultthanthoseobtainedbytheidealisotropicelastoplasticmodelandtheidealanisotropicelasto plasticmodel,respectively.
Theone-dimensionalthermalshockwaveinacarbon-phenoliccompositewastakenforan exampletodiscusstheinfluencesofconstitutivemodelsonnumericallysimulatedresultsofX-ray thermalshock wavesincomposite materials.Thecorrespondingnumericalsimulationswereperformedbyadoptingthreedifferentconstitutivemodels. Thesimulatedresultsrevealthatthepeak stressacquiredbytheanisotropicdynamicelasto-plasticconstitutivemodelislower,itsattenuationis fasteranditisbeclosertotheexperimentalresultthanthoseobtainedbytheidealisotropicelastoplasticmodelandtheidealanisotropicelasto plasticmodel,respectively.
2011, 31(6): 606-611.
doi: 10.11883/1001-1455(2011)06-0606-06
Abstract:
AnAlfoamenergyabsorberwasintroducedtoavibrationisolatingsystemtoreplacethe traditionalrigidandelasticbuffers.Andthecorrespondingtheoreticalanalysiswascarriedoutby comprehensivelyconsideringthetwoimportantindexes:themaximumaccelerationandthemaximum relativedisplacement.Basedonthetheoreticalanalysis,thevalidationexperimentswereconducted. TheexperimentalresultsshowthattheAlfoamenergyabsorbercaneffectivelypreventthewarship's equipmentsfromthesecondaryimpact.GoodagreementbetweentheexperimentalandtheoreticalresultsdisplaysthatthisinvestigationishelpfulfortheapplicationoftheAlfoamener yabsorbersin engineering.
AnAlfoamenergyabsorberwasintroducedtoavibrationisolatingsystemtoreplacethe traditionalrigidandelasticbuffers.Andthecorrespondingtheoreticalanalysiswascarriedoutby comprehensivelyconsideringthetwoimportantindexes:themaximumaccelerationandthemaximum relativedisplacement.Basedonthetheoreticalanalysis,thevalidationexperimentswereconducted. TheexperimentalresultsshowthattheAlfoamenergyabsorbercaneffectivelypreventthewarship's equipmentsfromthesecondaryimpact.GoodagreementbetweentheexperimentalandtheoreticalresultsdisplaysthatthisinvestigationishelpfulfortheapplicationoftheAlfoamener yabsorbersin engineering.
2011, 31(6): 612-618.
doi: 10.11883/1001-1455(2011)06-0612-07
Abstract:
Aimedatthefollowingcharacteristicsoftheexplosionexcitationseismicwaveincarbonate rockswhichincluding weakenergy,highfrequencyandlowsignal-to-noiseratio,anon-coupling chargecoefficientoftheseismicsourcewasdefinedtoimprovethehole-chargestructure.Calculation modelswereproposedforexplosionloadandtransmittedwaveenergy,andthecorrespondinganalyticalsolutionswerecalculatedbyprogramminginMATLAB. Andthen,thefieldexperimentationwas conductedandtheexperimentaldatawereanalyzedbyusingtheenergyanalysismethodbasedonpowerspectra. Boththetheoreticalcalculationandthefieldexperimentationshowthatthetotaltransmittedwaveenergyissmallerwhenthenon- couplingchargecoefficientisbigger,butthemainfrequency oftheseismicwaveislowerandthesignal-to-noiseratioisthehighestwhenthenon-couplingcoefficientis1.5. So,intheactualseismicexploration,thenon-couplingchargecoefficientof1.5canbeadoptedandthetotalseismicenergycanbeaugmentedbyincreasingthetotalchargemassinorderto improvetheseismicexcitationeffect.
Aimedatthefollowingcharacteristicsoftheexplosionexcitationseismicwaveincarbonate rockswhichincluding weakenergy,highfrequencyandlowsignal-to-noiseratio,anon-coupling chargecoefficientoftheseismicsourcewasdefinedtoimprovethehole-chargestructure.Calculation modelswereproposedforexplosionloadandtransmittedwaveenergy,andthecorrespondinganalyticalsolutionswerecalculatedbyprogramminginMATLAB. Andthen,thefieldexperimentationwas conductedandtheexperimentaldatawereanalyzedbyusingtheenergyanalysismethodbasedonpowerspectra. Boththetheoreticalcalculationandthefieldexperimentationshowthatthetotaltransmittedwaveenergyissmallerwhenthenon- couplingchargecoefficientisbigger,butthemainfrequency oftheseismicwaveislowerandthesignal-to-noiseratioisthehighestwhenthenon-couplingcoefficientis1.5. So,intheactualseismicexploration,thenon-couplingchargecoefficientof1.5canbeadoptedandthetotalseismicenergycanbeaugmentedbyincreasingthetotalchargemassinorderto improvetheseismicexcitationeffect.
2011, 31(6): 619-623.
doi: 10.11883/1001-1455(2011)06-0619-05
Abstract:
Inordertoinvestigatetheimpactcompressiveresponseofconfineddrysand,thedynamic compressionexperimentsofdrysandatdifferenthighstrainratesanddifferentpreloadswereconductedonthemodifiedsplitHopkinsonpressureb r(SHPB)withathinrubbercircularplateasapulse shaper.Quasi-staticcompressivepropertiesofthesandwereobtainedwithaMTS810materialstest system.Thematerialstudiedinthisresearchissilicabasedgrainsand,mostsandparticlesareinthe diameterrangefrom150to245m.Thedensityofthedrysandmaterialis1.40kg/m3withoutpreload. Theresultsshowthatthecompressionresponseofthedrysandisnotsensitivetostrainrate, butsignificantlydependentonthepreload.
Inordertoinvestigatetheimpactcompressiveresponseofconfineddrysand,thedynamic compressionexperimentsofdrysandatdifferenthighstrainratesanddifferentpreloadswereconductedonthemodifiedsplitHopkinsonpressureb r(SHPB)withathinrubbercircularplateasapulse shaper.Quasi-staticcompressivepropertiesofthesandwereobtainedwithaMTS810materialstest system.Thematerialstudiedinthisresearchissilicabasedgrainsand,mostsandparticlesareinthe diameterrangefrom150to245m.Thedensityofthedrysandmaterialis1.40kg/m3withoutpreload. Theresultsshowthatthecompressionresponseofthedrysandisnotsensitivetostrainrate, butsignificantlydependentonthepreload.
2011, 31(6): 624-629.
doi: 10.11883/1001-1455(2011)06-0624-06
Abstract:
Thequasi-staticBraziliantestwasperformedontheMTSmachinetoinvestigatethetensile fracturemodesofthePBXspecimen.AnopticalpreparationtechniqueforthePBXspecimenwasdevelopedtoobtainmorevividmicrostructurefeaturesunderopticalmicroscopes. Andthedeformation anddamageevolutionsofthespecimenweregainedbyadoptingahigh-speedcameraandthedigital imagecorrelationmethod.ResultsshowthatthetensilestrengthofthePBXislessthan3MPaand itsfailurestrainisconsiderablysmall.Basedontheobservedresults,thetensilefracturemodesofthe PBXexplosivespecimenwereanalyzedbyapplyingtheGriffithfracturecriterionandtheinterface debondingtheory.Analysisrevealsthattheinterfacedebondingcrackwillinitiateintheearlystageof loadandthetransgranularfractureleadstothefailureofthespecimen.Largercrystalsareproneto crackthroughthemselves,andsmalleronescankeepthemselvesfromtrangranularcleavagefracture butonlydebondfromthebinders.
Thequasi-staticBraziliantestwasperformedontheMTSmachinetoinvestigatethetensile fracturemodesofthePBXspecimen.AnopticalpreparationtechniqueforthePBXspecimenwasdevelopedtoobtainmorevividmicrostructurefeaturesunderopticalmicroscopes. Andthedeformation anddamageevolutionsofthespecimenweregainedbyadoptingahigh-speedcameraandthedigital imagecorrelationmethod.ResultsshowthatthetensilestrengthofthePBXislessthan3MPaand itsfailurestrainisconsiderablysmall.Basedontheobservedresults,thetensilefracturemodesofthe PBXexplosivespecimenwereanalyzedbyapplyingtheGriffithfracturecriterionandtheinterface debondingtheory.Analysisrevealsthattheinterfacedebondingcrackwillinitiateintheearlystageof loadandthetransgranularfractureleadstothefailureofthespecimen.Largercrystalsareproneto crackthroughthemselves,andsmalleronescankeepthemselvesfromtrangranularcleavagefracture butonlydebondfromthebinders.
2011, 31(6): 630-634.
doi: 10.11883/1001-1455(2011)06-0630-05
Abstract:
BasedonthenonlineardynamicssoftwareLS-DYNA,thecompleteprocessofjetparallel penetratingair/steeltargetinterfacewasnumericallysimulated.Byanalyzingtheprocessandresultof numericalsimulation,thevelocityoftheshapedchargejettipandthetransversevelocityafterimpact werediscussed.Theresultsshowthatattheair/steeltargetinterfacetheaxialvelocityoftheshaped chargejettipdecreasesevidentlyandtheshapedchargejettipisreducedtomovingtransversely,the highesttransversevelocityofwhichisabout1.8km/s;thatthetransversevelocitiesofthesubsequentjetsdecreasegraduallyandthejetdisruptionisantedated. Consequently,theair/steeltargetinterfacecanmarkedlydisturbtheshapedchargejettipandeffectivelyweakenthejetpenetration.
BasedonthenonlineardynamicssoftwareLS-DYNA,thecompleteprocessofjetparallel penetratingair/steeltargetinterfacewasnumericallysimulated.Byanalyzingtheprocessandresultof numericalsimulation,thevelocityoftheshapedchargejettipandthetransversevelocityafterimpact werediscussed.Theresultsshowthatattheair/steeltargetinterfacetheaxialvelocityoftheshaped chargejettipdecreasesevidentlyandtheshapedchargejettipisreducedtomovingtransversely,the highesttransversevelocityofwhichisabout1.8km/s;thatthetransversevelocitiesofthesubsequentjetsdecreasegraduallyandthejetdisruptionisantedated. Consequently,theair/steeltargetinterfacecanmarkedlydisturbtheshapedchargejettipandeffectivelyweakenthejetpenetration.
2011, 31(6): 635-640.
doi: 10.11883/1001-1455(2011)06-0635-06
Abstract:
Basedonthefiniteelementanalysissoftware,afiniteelementmodelwasestablishedforthe rapid-firingguncross-sectiontoexploretheresidualstressintheautofrettagedbarrel,whichwasinfluencedbythehigh- temperature,high-pressureandhigh-speedexplosivegaswhenshooting.And thedirectcouplingmethodwasemployedasasolvingstrategytoanalyzetheresidualstressintheautofrettagedbarrelintheprocessof50continuo sshotsfirstand10shotsaftercooling.Investigated resultdisplaysthattherepeatedchangingoftheplasticstrainandresidualstressintheinnerwallis harmfultothestabilizationoftheinnerwall.Andthe measureswereputforwardtoreducethe changeoftheresidualstress.
Basedonthefiniteelementanalysissoftware,afiniteelementmodelwasestablishedforthe rapid-firingguncross-sectiontoexploretheresidualstressintheautofrettagedbarrel,whichwasinfluencedbythehigh- temperature,high-pressureandhigh-speedexplosivegaswhenshooting.And thedirectcouplingmethodwasemployedasasolvingstrategytoanalyzetheresidualstressintheautofrettagedbarrelintheprocessof50continuo sshotsfirstand10shotsaftercooling.Investigated resultdisplaysthattherepeatedchangingoftheplasticstrainandresidualstressintheinnerwallis harmfultothestabilizationoftheinnerwall.Andthe measureswereputforwardtoreducethe changeoftheresidualstress.
2011, 31(6): 641-646.
doi: 10.11883/1001-1455(2011)06-0641-06
Abstract:
Thesimilitudewasanalyzedbetweenthecharacteristicsofexplosionbubblesgeneratedby laser-inducedbreakdownanddetonatorexplosioninwater.Bycombiningahighpowerlaser,anopticalfocussystem, ahigh-speedcameraandahydrophone,ameasurementsystemwasdevelopedtoexperimentallyinvestigatethelaser- inducedbreakdowninliquidssuchaswater,alcohol,siliconinthe casesofthedifferentlaserenergy.Basedonthedevelopedmeasurementsystem,aseriesoflaser-inducedbubblecharacteristicswereobtained, whichincludedtheimagelistsofexplosionbubbledynamics, expansionandcollapse,andtheparametersofexplosionbubblediameterevolvements,bubbleexpansionandcollapseshockwavevelocitiesandacousticsignalintensities.
Thesimilitudewasanalyzedbetweenthecharacteristicsofexplosionbubblesgeneratedby laser-inducedbreakdownanddetonatorexplosioninwater.Bycombiningahighpowerlaser,anopticalfocussystem, ahigh-speedcameraandahydrophone,ameasurementsystemwasdevelopedtoexperimentallyinvestigatethelaser- inducedbreakdowninliquidssuchaswater,alcohol,siliconinthe casesofthedifferentlaserenergy.Basedonthedevelopedmeasurementsystem,aseriesoflaser-inducedbubblecharacteristicswereobtained, whichincludedtheimagelistsofexplosionbubbledynamics, expansionandcollapse,andtheparametersofexplosionbubblediameterevolvements,bubbleexpansionandcollapseshockwavevelocitiesandacousticsignalintensities.
2011, 31(6): 647-652.
doi: 10.11883/1001-1455(2011)06-0647-06
Abstract:
WiththehelpofANSYS/LS-DYNAfiniteelementsoftware,thedirectionalblastingcollapseprocessofacertainhighframe- shearwallstructurewasnumericallysimulatedbyusingtheintegralmodelandcommonnodeseparatemodel. Andthenumericallysimulatedresultswerecompared withtheactualproject.Comparisonsshowthatthesimulatedresultsbyusingthecommonnodeseparatemodelareinbetteragreementwiththeactualproject. Inaddition,thenumericallysimulatedresultsdisplaythatthecollapsescopeofthestructurecanbereducedbyproperlyascendingtheblasting cutofthestructure.Finally,thestress-timecurvesofthesteelandconcreteelementsindicatethatthe commonnodeseparatereinforcedconcretemodelcancorrectlyreflectthemechanicalpropertydifferencesbetweensteelandconcrete.
WiththehelpofANSYS/LS-DYNAfiniteelementsoftware,thedirectionalblastingcollapseprocessofacertainhighframe- shearwallstructurewasnumericallysimulatedbyusingtheintegralmodelandcommonnodeseparatemodel. Andthenumericallysimulatedresultswerecompared withtheactualproject.Comparisonsshowthatthesimulatedresultsbyusingthecommonnodeseparatemodelareinbetteragreementwiththeactualproject. Inaddition,thenumericallysimulatedresultsdisplaythatthecollapsescopeofthestructurecanbereducedbyproperlyascendingtheblasting cutofthestructure.Finally,thestress-timecurvesofthesteelandconcreteelementsindicatethatthe commonnodeseparatereinforcedconcretemodelcancorrectlyreflectthemechanicalpropertydifferencesbetweensteelandconcrete.
2011, 31(6): 653-657.
doi: 10.11883/1001-1455(2011)06-0653-05
Abstract:
BasedontheJohnson-CookmaterialmodelandtheGrneisenequationofstate,athermoplastichydrodynamicmodelwasestablishedbyadoptingthesmoothparticlehydrodynamics( SPH) methodintheANSYS/LS-DYNA11.0tonumericallysimulatetheformationandevolutionprocesses oftheinterfacewavesinthesteel-steelexplosivewelding.ThesimulatedresultsrevealthattheSPH methodcanbeusedtoobtainvividinterfacewaveappearancesinexplosivewelding.Comparisonsbetweenthesimulatedresultsandtheexistentexperimentalonesdisplaythatthesimulationerrorsare smallandtheydecreasewiththecollisionvelocityincreaseoftheflyerplate.Sotheestablishedthermoplastichydrodynamicmodelisapplicabletotheinterfacewaveinvestigationinexplosivewelding, especiallytooneswithhighercollisionvelocities.
BasedontheJohnson-CookmaterialmodelandtheGrneisenequationofstate,athermoplastichydrodynamicmodelwasestablishedbyadoptingthesmoothparticlehydrodynamics( SPH) methodintheANSYS/LS-DYNA11.0tonumericallysimulatetheformationandevolutionprocesses oftheinterfacewavesinthesteel-steelexplosivewelding.ThesimulatedresultsrevealthattheSPH methodcanbeusedtoobtainvividinterfacewaveappearancesinexplosivewelding.Comparisonsbetweenthesimulatedresultsandtheexistentexperimentalonesdisplaythatthesimulationerrorsare smallandtheydecreasewiththecollisionvelocityincreaseoftheflyerplate.Sotheestablishedthermoplastichydrodynamicmodelisapplicabletotheinterfacewaveinvestigationinexplosivewelding, especiallytooneswithhighercollisionvelocities.
2011, 31(6): 658-663.
doi: 10.11883/1001-1455(2011)06-0658-06
Abstract:
Byintegratingtheelement-freeGalerkin(EFG)methodwiththeLS-DYNAsoftware,ananalysismodelforperforationandpenetrationwasdevelopedtonumericallysimulatethepenetrationof aspherical-noseprojectileintoasemi-infinitesteeltargetinthreedimensions.Thesimulatedresults werecomparedwiththeonesbythecavityexpansiontheoryandthefiniteelementmethod.ThecomparisondemonstratesthefeasibilityandsuperiorityoftheEFG methodinthesimulationofperforationandpenetration.
Byintegratingtheelement-freeGalerkin(EFG)methodwiththeLS-DYNAsoftware,ananalysismodelforperforationandpenetrationwasdevelopedtonumericallysimulatethepenetrationof aspherical-noseprojectileintoasemi-infinitesteeltargetinthreedimensions.Thesimulatedresults werecomparedwiththeonesbythecavityexpansiontheoryandthefiniteelementmethod.ThecomparisondemonstratesthefeasibilityandsuperiorityoftheEFG methodinthesimulationofperforationandpenetration.
2011, 31(6): 664-668.
doi: 10.11883/1001-1455(2011)06-0664-05
Abstract:
Accordingtotherelationbetweenthemetalconductorsspecificactionandresistivityand theanalyticalformulaforthevariationoftheexplodingwirewithtimebroughtforwardbyHobson, twocomputationalmodelsweredevelopedtoexploretheelectricalcharacteristicsofanelectricexplodingcopperwireopeningswitch (EEOS)byusingthesoftwarePspice.Andthevoltageacrossthe EEOSwasexperimentallyobtained.TheexperimentalresultsindicatethattheHobsonmodeliseffectiveonlybeforethevaporizationoftheelectricexplodingcopperwire; thatthespecificaction-resistivitymodelcanbeusedtomacroscopicallydescribethewholeelectricexplodingprocess. Sothesetwo modelscanbeusedtosimulatethehigh-voltageandhigh-currentcircuitswiththeEEOSs,andthe simulatedresultsarehelpfulforthedesignoftheEEOSs.
Accordingtotherelationbetweenthemetalconductorsspecificactionandresistivityand theanalyticalformulaforthevariationoftheexplodingwirewithtimebroughtforwardbyHobson, twocomputationalmodelsweredevelopedtoexploretheelectricalcharacteristicsofanelectricexplodingcopperwireopeningswitch (EEOS)byusingthesoftwarePspice.Andthevoltageacrossthe EEOSwasexperimentallyobtained.TheexperimentalresultsindicatethattheHobsonmodeliseffectiveonlybeforethevaporizationoftheelectricexplodingcopperwire; thatthespecificaction-resistivitymodelcanbeusedtomacroscopicallydescribethewholeelectricexplodingprocess. Sothesetwo modelscanbeusedtosimulatethehigh-voltageandhigh-currentcircuitswiththeEEOSs,andthe simulatedresultsarehelpfulforthedesignoftheEEOSs.
2011, 31(6): 669-672.
doi: 10.11883/1001-1455(2011)06-0669-04
Abstract:
Accordingtotheblastingexperiencesandactualexplosion-in-rockinducedrockfragmentation, theshockwaveenergyproducedbytheliquidexplosiveexplosionwasseparatedintothesurface energyofthefracturedrockandthestrainenergyintherockbyapplyingtheenergyconservationlaw. Andbasedontherockfracturemechanicsprinciple,amodelwasproposedtopredicatethefragmented rockparticlesizesinthecrackedregion.Acalculationexamplewasgiveninwhichthediameterofthe fragmentedrockparticleswas1.43mm.Thecalculatedresultsdisplaythatthediameterofthefragmentedrockparticlegeneratedbytheliquidexplosiveexplosioninrockisequivalentt thatofthehydraulicfracturingproppantparticleintheoilindustry.
Accordingtotheblastingexperiencesandactualexplosion-in-rockinducedrockfragmentation, theshockwaveenergyproducedbytheliquidexplosiveexplosionwasseparatedintothesurface energyofthefracturedrockandthestrainenergyintherockbyapplyingtheenergyconservationlaw. Andbasedontherockfracturemechanicsprinciple,amodelwasproposedtopredicatethefragmented rockparticlesizesinthecrackedregion.Acalculationexamplewasgiveninwhichthediameterofthe fragmentedrockparticleswas1.43mm.Thecalculatedresultsdisplaythatthediameterofthefragmentedrockparticlegeneratedbytheliquidexplosiveexplosioninrockisequivalentt thatofthehydraulicfracturingproppantparticleintheoilindustry.
