2012 Vol. 32, No. 1
Display Method:
2012, 32(1): 1-7.
doi: 10.11883/1001-1455(2012)01-0001-07
PDF 
Cited by
Abstract:
Pressureprofileofplasmaisoneofthemostimportantfactorsfortheeffectsoflasershock peening.Inthepresentresearch,aone-dimensionalcouplingmodelforcomputingplasmapressureis establishedbasedonenergyconservationconditioninthesystem,inwhichtheinterfacevaporization velocityandthenonlinearrelationshipbetweentheshockpressureandthesurfaceparticlevelocityare considered.Then,theexplicitdifferenceprogramandtheLS-DYNApackageareusedtocalculatethe plasmapressurefordifferentlaserpowerdensitywithgiventime-historyprofile.Thesimulationresultsshowagoodagreementwiththeexperimentalresults, whichindicatestheconsistencyoftheanalyticalmodel. Therefore,aneffectivemethodisprovidedtopredicttheplasmapressureinducedby lasershockpeening.
Pressureprofileofplasmaisoneofthemostimportantfactorsfortheeffectsoflasershock peening.Inthepresentresearch,aone-dimensionalcouplingmodelforcomputingplasmapressureis establishedbasedonenergyconservationconditioninthesystem,inwhichtheinterfacevaporization velocityandthenonlinearrelationshipbetweentheshockpressureandthesurfaceparticlevelocityare considered.Then,theexplicitdifferenceprogramandtheLS-DYNApackageareusedtocalculatethe plasmapressurefordifferentlaserpowerdensitywithgiventime-historyprofile.Thesimulationresultsshowagoodagreementwiththeexperimentalresults, whichindicatestheconsistencyoftheanalyticalmodel. Therefore,aneffectivemethodisprovidedtopredicttheplasmapressureinducedby lasershockpeening.
2012, 32(1): 8-14.
doi: 10.11883/1001-1455(2012)01-0008-07
Abstract:
Thestresstriaxialityisthemostimportantfactorthatcontrolsinitiationofductilefracture, besidesthestrainlevel.Quasi-statictensiletestsonsmoothandnotchedspecimensofhighstrength steelwerecarriedout,andnumericalsimulationsofthetestswereperformedusingfiniteelement codeABAQUS.Basedontheexperimentalandnumericalresults,somematerialparametersofthe Johnson-Cookconstitutivemodelandthefracturemodelwereobtained.Finally,rectangularplates madeofthehighstrengthsteelwerecollidedbydroppingpunch,andnumericalsimulationswereperformedusingtheJohnson- Cookmodelobtainedpreviously.Goodagreementswerefoundbetweenthe testsandthenumericalresults,whichillustratedthatitwasreliabletoupdatethestresstriaxialityby numericalsimulationsoftensiletests.
Thestresstriaxialityisthemostimportantfactorthatcontrolsinitiationofductilefracture, besidesthestrainlevel.Quasi-statictensiletestsonsmoothandnotchedspecimensofhighstrength steelwerecarriedout,andnumericalsimulationsofthetestswereperformedusingfiniteelement codeABAQUS.Basedontheexperimentalandnumericalresults,somematerialparametersofthe Johnson-Cookconstitutivemodelandthefracturemodelwereobtained.Finally,rectangularplates madeofthehighstrengthsteelwerecollidedbydroppingpunch,andnumericalsimulationswereperformedusingtheJohnson- Cookmodelobtainedpreviously.Goodagreementswerefoundbetweenthe testsandthenumericalresults,whichillustratedthatitwasreliabletoupdatethestresstriaxialityby numericalsimulationsoftensiletests.
2012, 32(1): 15-22.
doi: 10.11883/1001-1455(2012)01-0015-08
Abstract:
Abstract:AkineticinterfacefrictionmodelisproposedbasedonthekineticfrictiontestsbyMengto describethevariationofkineticfrictioncoefficientwiththemaximumradialrelativevelocitybetween theSHPBpolycarbonate(PC)specimenandsteelpressurebars.Thekineticinterfacefrictionmodel andtheconstantfrictioncoefficientmodelareimplementedintothenumericalsimulationsofSHPB tests.Itshowsthatusingdifferentinterfacialfrictionmodelshaslittleinfluenceonthetransitional strainrate(intheorderof102s-1)obtainedfromthenumericalsimulationsofSHPBtestsonpolymerspecimens. Whilethestrain-rateexceedsthetransitionalstrainrate,thisinfluenceisobvious, anditisnecessarytousethekineticinterfacialfrictionmodel,ratherthantheconstantfrictioncoefficientmodelforobtainingmoreaccuratenumericalsimulationsofSHPBtestsonpolymerspecimens.
Abstract:AkineticinterfacefrictionmodelisproposedbasedonthekineticfrictiontestsbyMengto describethevariationofkineticfrictioncoefficientwiththemaximumradialrelativevelocitybetween theSHPBpolycarbonate(PC)specimenandsteelpressurebars.Thekineticinterfacefrictionmodel andtheconstantfrictioncoefficientmodelareimplementedintothenumericalsimulationsofSHPB tests.Itshowsthatusingdifferentinterfacialfrictionmodelshaslittleinfluenceonthetransitional strainrate(intheorderof102s-1)obtainedfromthenumericalsimulationsofSHPBtestsonpolymerspecimens. Whilethestrain-rateexceedsthetransitionalstrainrate,thisinfluenceisobvious, anditisnecessarytousethekineticinterfacialfrictionmodel,ratherthantheconstantfrictioncoefficientmodelforobtainingmoreaccuratenumericalsimulationsofSHPBtestsonpolymerspecimens.
2012, 32(1): 23-28.
doi: 10.11883/1001-1455(2012)01-0023-06
Abstract:
Thedynamicmechanicalpropertiesofhexagonalaluminum honeycombswithvariouscell configurationsarestudiedbyemployingtheexplicitdynamicnumericalsimulations.Thedeformation modeandthecrushingstrengthofthehoneycombs,aswellastheinfluencefactorsarediscussed. Fivekindsofcellconfigurationsareacquiredbychangingthecell-wallangle,andthreelevelsofimpactvelocityareinvolvedinthenumericalsimulations. Theresultsshowthatunderthequasi-static deformationmode,thecrushingstrengthofthehoneycombsisdominatedbythecellconfiguration. Oncethehoneycombsdeformationturnsintothedynamicmode,theinertiaeffectisnotableandbecomesthedecidingfactorofthehoneycombscrushingstrength, whiletheinfluenceofthecellconfigurationisinconspicuous. Underthetransitionalmode,thecrushingstrengthofthehoneycombsisdeterminedbyboththeinertiaeffectandthecellconfigurationsimultaneously. Moreover,thehigher theimpactvelocity,themoresignificanttheproportioninertiaeffect.
Thedynamicmechanicalpropertiesofhexagonalaluminum honeycombswithvariouscell configurationsarestudiedbyemployingtheexplicitdynamicnumericalsimulations.Thedeformation modeandthecrushingstrengthofthehoneycombs,aswellastheinfluencefactorsarediscussed. Fivekindsofcellconfigurationsareacquiredbychangingthecell-wallangle,andthreelevelsofimpactvelocityareinvolvedinthenumericalsimulations. Theresultsshowthatunderthequasi-static deformationmode,thecrushingstrengthofthehoneycombsisdominatedbythecellconfiguration. Oncethehoneycombsdeformationturnsintothedynamicmode,theinertiaeffectisnotableandbecomesthedecidingfactorofthehoneycombscrushingstrength, whiletheinfluenceofthecellconfigurationisinconspicuous. Underthetransitionalmode,thecrushingstrengthofthehoneycombsisdeterminedbyboththeinertiaeffectandthecellconfigurationsimultaneously. Moreover,thehigher theimpactvelocity,themoresignificanttheproportioninertiaeffect.
2012, 32(1): 29-33.
doi: 10.11883/1001-1455(2012)01-0029-05
Abstract:
ToexploretheformationmechanismoftandemEFP,experimentalandnumericalstudieson theformationprocessofshapedchargewithdoublelayerliners(SCDLL)intotandemEFPwerepresented. Fourtestsampleswithdifferentmaterialsweredesigned.Thesampleswereexperimentally testedtogetX-rayimages.Numericalsimulationswerethenperformedforthetestsamplesusing AUTODYN-2D.Basedontheexperimentalandnumericalinvestigations,analysiswasmadetofind thekeyfactorswhichinfluencetheformationprocessofSCDLL.ItisfoundthatSCDLLcanalways beseparatedintotwoprojectileswithcertainconfigurationandlinermaterials.Thecombinationof linermaterialandtheignitionpositionhavegreatinfluenceontheformationoftandemEFP.
ToexploretheformationmechanismoftandemEFP,experimentalandnumericalstudieson theformationprocessofshapedchargewithdoublelayerliners(SCDLL)intotandemEFPwerepresented. Fourtestsampleswithdifferentmaterialsweredesigned.Thesampleswereexperimentally testedtogetX-rayimages.Numericalsimulationswerethenperformedforthetestsamplesusing AUTODYN-2D.Basedontheexperimentalandnumericalinvestigations,analysiswasmadetofind thekeyfactorswhichinfluencetheformationprocessofSCDLL.ItisfoundthatSCDLLcanalways beseparatedintotwoprojectileswithcertainconfigurationandlinermaterials.Thecombinationof linermaterialandtheignitionpositionhavegreatinfluenceontheformationoftandemEFP.
2012, 32(1): 34-42.
doi: 10.11883/1001-1455(2012)01-0034-09
Abstract:
Inordertobetterunderstandthedynamicbehaviorofratesensitivematerialandstructure, acomputationalmodelforthedynamicresponseanalysisofamildsteelbeamsubjectedtosquare pulseloadingispresented,whichisderivedthroughdiscretizingdirectlytheLeefunctionaltobeappliedintheminimumprincipleofaccelerationofelastic- plasticcontinuaatfinitedeformation.Since thestrainratedependentCowper-Symondsequationisintegratedintostress-strainrelationequations, theeffectsofstrainratecouldbetakenintoaccount,andthedynamicresponseofsteelbeamunder explosionandimpactloadcouldbepredictedaccurately.Thevalidityofthemodelisverifiedbysimulatedresultsfromthegeneral- purposefiniteelementprogram ABAQUSandfurthercomparedwith therigid-plasticsolutions.Basedonnumericalsimulationofthismodel,theeffectofstrainrateon dynamicresponseofsteelbeamunderuniformlydistributingandconcentratepulseloadsisdiscussed indetail.Thenumericalresultsshowthatthereisanovelresponsemodeofabnormalbehaviorofthe steelbeams,theabnormalwindowisshiftedandenlarged,andtheactualpermanentdeflectionof steelbeamcannotbepredictedbypreviousrigid-plasticmodelincertainrangeofloadmagnitude.
Inordertobetterunderstandthedynamicbehaviorofratesensitivematerialandstructure, acomputationalmodelforthedynamicresponseanalysisofamildsteelbeamsubjectedtosquare pulseloadingispresented,whichisderivedthroughdiscretizingdirectlytheLeefunctionaltobeappliedintheminimumprincipleofaccelerationofelastic- plasticcontinuaatfinitedeformation.Since thestrainratedependentCowper-Symondsequationisintegratedintostress-strainrelationequations, theeffectsofstrainratecouldbetakenintoaccount,andthedynamicresponseofsteelbeamunder explosionandimpactloadcouldbepredictedaccurately.Thevalidityofthemodelisverifiedbysimulatedresultsfromthegeneral- purposefiniteelementprogram ABAQUSandfurthercomparedwith therigid-plasticsolutions.Basedonnumericalsimulationofthismodel,theeffectofstrainrateon dynamicresponseofsteelbeamunderuniformlydistributingandconcentratepulseloadsisdiscussed indetail.Thenumericalresultsshowthatthereisanovelresponsemodeofabnormalbehaviorofthe steelbeams,theabnormalwindowisshiftedandenlarged,andtheactualpermanentdeflectionof steelbeamcannotbepredictedbypreviousrigid-plasticmodelincertainrangeofloadmagnitude.
2012, 32(1): 43-46.
doi: 10.11883/1001-1455(2012)01-0043-04
Abstract:
Toexploretheapplicationoffoam materialstospaceprotection,theballisticlimitcurveof analuminumfoam-filledshieldwasobtainedinthevelocityrangefrom0.5to7.0km/sbyexperimentsandnumericalsimulation, whichwascomparedwiththatoftheWhippleshield.Theresults showthatthealuminumfoam-filledshieldhashigherspace-debrisprotectionperformancethanthe Whippleshieldwiththesamearealdensityandthickness;andthatthefoamporosityhasfewinfluencesontheprotectionperformanceofthealuminumfoam- filledshield.
Toexploretheapplicationoffoam materialstospaceprotection,theballisticlimitcurveof analuminumfoam-filledshieldwasobtainedinthevelocityrangefrom0.5to7.0km/sbyexperimentsandnumericalsimulation, whichwascomparedwiththatoftheWhippleshield.Theresults showthatthealuminumfoam-filledshieldhashigherspace-debrisprotectionperformancethanthe Whippleshieldwiththesamearealdensityandthickness;andthatthefoamporosityhasfewinfluencesontheprotectionperformanceofthealuminumfoam- filledshield.
2012, 32(1): 47-50.
doi: 10.11883/1001-1455(2012)01-0047-04
Abstract:
Tramcarsareusedastransportequipment,especiallyinthecentralareaofamine.Asobstaclesinthecloudofpre- mixedgas,theyproducestimulatingeffectduringthemethaneexplosionaccidentsincoalmining. Basedonconditionsofcoalminingprocess,asetofmodelsisbuiltforthenumericalsimulation. Thechemicalreactionmechanism,thermodynamicsofexplosionandelementary reactionaretakenintoconsiderationinthesimulation.TheTVDschemeisusedfornumericaldiscretization. Theresultshowsthechangesofshockwaveandfireflamebecauseoftheinfluenceof1to3 tramcars.Bycomparisonwithpreviousexperimentalresults,theconclusionisthatthestimulating effectwillbeenhancedwiththeincreaseofthenumberoftramcars.Theresultwillbehelpfulforthe gasexplosionprevention,emergencyresponseandrescue,andincidentinvestigationincoalmines.
Tramcarsareusedastransportequipment,especiallyinthecentralareaofamine.Asobstaclesinthecloudofpre- mixedgas,theyproducestimulatingeffectduringthemethaneexplosionaccidentsincoalmining. Basedonconditionsofcoalminingprocess,asetofmodelsisbuiltforthenumericalsimulation. Thechemicalreactionmechanism,thermodynamicsofexplosionandelementary reactionaretakenintoconsiderationinthesimulation.TheTVDschemeisusedfornumericaldiscretization. Theresultshowsthechangesofshockwaveandfireflamebecauseoftheinfluenceof1to3 tramcars.Bycomparisonwithpreviousexperimentalresults,theconclusionisthatthestimulating effectwillbeenhancedwiththeincreaseofthenumberoftramcars.Theresultwillbehelpfulforthe gasexplosionprevention,emergencyresponseandrescue,andincidentinvestigationincoalmines.
2012, 32(1): 51-54.
doi: 10.11883/1001-1455(2012)01-0051-04
Abstract:
Inengineeringapplicationofexplosionweldingoflarge-sizedTi/steelplates,weldingdefectsarealwaysfoundintheparticularareaofplatesboundary. Inordertosolvethisproblem,the dynamicprocessofexplosionweldingisinvestigatedbythenumericalsimulation.Foldingdeformationcanbediscoveredduringtheexplosionweldingbasedontheresearchonthemorphologicalchangesoftheflyerplateatdiffere ttimes.Thecalculationresultsareingoodagreementwiththeexperiments. Thestudiesshowthatfoldingdeformationisacrucialproblemwhichshouldbenoticedinthe processofexplosivewelding.Thereasonsforthefoldingdeformationarediscussedinthepaper.The conclusioncanprovideareferenceforthedevelopmentofexplosionweldingtechnology.
Inengineeringapplicationofexplosionweldingoflarge-sizedTi/steelplates,weldingdefectsarealwaysfoundintheparticularareaofplatesboundary. Inordertosolvethisproblem,the dynamicprocessofexplosionweldingisinvestigatedbythenumericalsimulation.Foldingdeformationcanbediscoveredduringtheexplosionweldingbasedontheresearchonthemorphologicalchangesoftheflyerplateatdiffere ttimes.Thecalculationresultsareingoodagreementwiththeexperiments. Thestudiesshowthatfoldingdeformationisacrucialproblemwhichshouldbenoticedinthe processofexplosivewelding.Thereasonsforthefoldingdeformationarediscussedinthepaper.The conclusioncanprovideareferenceforthedevelopmentofexplosionweldingtechnology.
2012, 32(1): 55-60.
doi: 10.11883/1001-1455(2012)01-0055-06
Abstract:
Thewaterentryproblemofthe2-D wedgewithaconstantspeedisnumericallyanalyzed basedonthevelocitypotentialtheory.Anewjetlinearapproximationmethodisincorporatedintothe complexvariableboundaryelementsolverthatdescribesthejetgeneratedbythewaterentryofwedgestonearlysimulatethefreesurfaceshape, jetandpressuredistributionalongthewettedareaofthe wedgecontour.AndthesametimeCauchyintegraltheoremisusedastheintegrationequation,and thesimilaritysolutionastheinitialcondition.Someimportantnumericaltechniquesarediscussedin detailsuchastimemarchingsolution,jettreatment,gridmeshgenerationandthefreesurfacedeformationupdating. Finally,thepressuredistributionandwaveelevationforthewedgeswithdifferentdeadriseanglesaregotten. Theproposedmethodisvalidatedthroughcomparisonswiththesimilaritysolutionandgoodapproximationsarefound.
Thewaterentryproblemofthe2-D wedgewithaconstantspeedisnumericallyanalyzed basedonthevelocitypotentialtheory.Anewjetlinearapproximationmethodisincorporatedintothe complexvariableboundaryelementsolverthatdescribesthejetgeneratedbythewaterentryofwedgestonearlysimulatethefreesurfaceshape, jetandpressuredistributionalongthewettedareaofthe wedgecontour.AndthesametimeCauchyintegraltheoremisusedastheintegrationequation,and thesimilaritysolutionastheinitialcondition.Someimportantnumericaltechniquesarediscussedin detailsuchastimemarchingsolution,jettreatment,gridmeshgenerationandthefreesurfacedeformationupdating. Finally,thepressuredistributionandwaveelevationforthewedgeswithdifferentdeadriseanglesaregotten. Theproposedmethodisvalidatedthroughcomparisonswiththesimilaritysolutionandgoodapproximationsarefound.
2012, 32(1): 61-66.
doi: 10.11883/1001-1455(2012)01-0061-06
Abstract:
Basedonthewavetheory,thispaperputsforwardthedesignprinciplesoftheprotectionagainstunderwaterexplosionshockwave. Besides,inlightoftheactualsituationofsafetyprotectionin underwaterblastingpractices,experimentalstudiesarecarriedouttotestthehypothesesregarding theattenuationofunderwatershockwavebytheairinterlayer.Itisfoundthattheairinterlayercan effectivelyattenuatetheshockwavepeakpressure.Inordertostudytheenergydistributioncharacteristicsoftheattenuationofunderwatershockwavebytheairinterlayer, thepaperproposesawayof approachingtheenergydistributionofunderwaterexplosionshockwavesfromwaveletanalysis.Given thattheenergydistributionofunderwaterexplosionshockwavesiswidelyrangedinfrequency,the paperfindsoutthatundertheimpactoftheairinterlayer,theshockwaveenergyineachfrequency rangehasdesirableattenuatingcapability,andthattheattenuatedshockwaveenergyinthemajorityof frequencyrangescanamountto50%oftheoriginal.Theresearchresultsshowthat,theairinterlayer playsapositiveroleinstrengtheningthesafetyprotectioninunderwaterblastingandeffectivelyreducethedestructiveeffectsofunderwatere plosionshockwaves,andhencehasapracticalvalue.
Basedonthewavetheory,thispaperputsforwardthedesignprinciplesoftheprotectionagainstunderwaterexplosionshockwave. Besides,inlightoftheactualsituationofsafetyprotectionin underwaterblastingpractices,experimentalstudiesarecarriedouttotestthehypothesesregarding theattenuationofunderwatershockwavebytheairinterlayer.Itisfoundthattheairinterlayercan effectivelyattenuatetheshockwavepeakpressure.Inordertostudytheenergydistributioncharacteristicsoftheattenuationofunderwatershockwavebytheairinterlayer, thepaperproposesawayof approachingtheenergydistributionofunderwaterexplosionshockwavesfromwaveletanalysis.Given thattheenergydistributionofunderwaterexplosionshockwavesiswidelyrangedinfrequency,the paperfindsoutthatundertheimpactoftheairinterlayer,theshockwaveenergyineachfrequency rangehasdesirableattenuatingcapability,andthattheattenuatedshockwaveenergyinthemajorityof frequencyrangescanamountto50%oftheoriginal.Theresearchresultsshowthat,theairinterlayer playsapositiveroleinstrengtheningthesafetyprotectioninunderwaterblastingandeffectivelyreducethedestructiveeffectsofunderwatere plosionshockwaves,andhencehasapracticalvalue.
2012, 32(1): 67-72.
doi: 10.11883/1001-1455(2012)01-0067-06
Abstract:
Experimentandnumericalsimulationwereperformedbyusing1kgcylindricalaluminized explosivecasedby6 mmthicksteelandaluminumshells,respectively.Theresultsshowthatthe steelshellcanenhancetheimpulse,shockwaveenergyanddecaytimecomparedwiththealuminum shell.Andtheinfluencesofthesteelshellthicknesswereanalyzed.Withtheincreaseofthethickness, theshockwavewereenhancedandthenweaken,andtherewasalag-effectforthepeakpressure oftheshockwave.Foragivenmassofexplosive,thereliesanoptimumshellthicknessforenhancing theshockwavepeakpressure.Fordifferentmass,themassratioofshelltoexplosiveisanimportant parameterforestimatingtheunderwaterexplosionofcasedexplosive.
Experimentandnumericalsimulationwereperformedbyusing1kgcylindricalaluminized explosivecasedby6 mmthicksteelandaluminumshells,respectively.Theresultsshowthatthe steelshellcanenhancetheimpulse,shockwaveenergyanddecaytimecomparedwiththealuminum shell.Andtheinfluencesofthesteelshellthicknesswereanalyzed.Withtheincreaseofthethickness, theshockwavewereenhancedandthenweaken,andtherewasalag-effectforthepeakpressure oftheshockwave.Foragivenmassofexplosive,thereliesanoptimumshellthicknessforenhancing theshockwavepeakpressure.Fordifferentmass,themassratioofshelltoexplosiveisanimportant parameterforestimatingtheunderwaterexplosionofcasedexplosive.
2012, 32(1): 73-78.
doi: 10.11883/1001-1455(2012)01-0073-06
Abstract:
Theblastingdemolitionprocessesofatypicaltoweringtubbystructurecoolingtowerwere numericallysimulatedbyadoptingthecommonnodeseparatereinforcedconcretemodeltocompare thetwodemolitiondesignswithcuttingseamandwithoutcuttingseaminthemiddleofthetower gap,respectively.Thecommonnodeseparatemodelcanreflectthedifferencesbetweenthemechanicalpropertiesofconcreteandreinforcementthroughanalysisonthe rloadingprocess.Thestructure sittingdownandbackbreaktendencyinthecollapseprocesscandecreasebyadoptingthecutting seamdesign,whichcanmakethebackofthetowerseriouslydistortandinducethetowertomore completelydisintegrate,anditcanalsodecreasethewholecollapsetimeandtherangeofthemuck pile.
Theblastingdemolitionprocessesofatypicaltoweringtubbystructurecoolingtowerwere numericallysimulatedbyadoptingthecommonnodeseparatereinforcedconcretemodeltocompare thetwodemolitiondesignswithcuttingseamandwithoutcuttingseaminthemiddleofthetower gap,respectively.Thecommonnodeseparatemodelcanreflectthedifferencesbetweenthemechanicalpropertiesofconcreteandreinforcementthroughanalysisonthe rloadingprocess.Thestructure sittingdownandbackbreaktendencyinthecollapseprocesscandecreasebyadoptingthecutting seamdesign,whichcanmakethebackofthetowerseriouslydistortandinducethetowertomore completelydisintegrate,anditcanalsodecreasethewholecollapsetimeandtherangeofthemuck pile.
2012, 32(1): 79-83.
doi: 10.11883/1001-1455(2012)01-0079-05
Abstract:
BasedontheHeldinitiationtheory,andthefactthatshapedchargejetagainstthecharge canproducelowvelocityexplosion,thispaperpresentsanewdesignofmicro-acousticshapedcharge device.Theorthogonalanalysismethodswereappliedtooptimizethechargestructure.Theexperimentsindicatethatthenoiseeliminationabilityandtheanti- detonationabilityofthedevicearefine. Thesimulatorchargeboxesweredestroyedwithlowvelocitydetonation,whichhelpsreducetheexplosiveharmandallowsfordestroyingIEDsafely.
BasedontheHeldinitiationtheory,andthefactthatshapedchargejetagainstthecharge canproducelowvelocityexplosion,thispaperpresentsanewdesignofmicro-acousticshapedcharge device.Theorthogonalanalysismethodswereappliedtooptimizethechargestructure.Theexperimentsindicatethatthenoiseeliminationabilityandtheanti- detonationabilityofthedevicearefine. Thesimulatorchargeboxesweredestroyedwithlowvelocitydetonation,whichhelpsreducetheexplosiveharmandallowsfordestroyingIEDsafely.
2012, 32(1): 84-90.
doi: 10.11883/1001-1455(2012)01-0084-07
Abstract:
Basedonthesuperpositionprincipleofseismicwaves,anewblastingvibrationwaveform predictionmodelwasproposedotherthanthetraditionalpredictionmethodsfoundedondatastatistics. Accordingtothemeasuredvibrationwaveformsfromsingleblastholes,thedevelopedmodel wasusedtocalculatetheblastingvibrationwaveformsatcertainlocations.Inthecalculation,theparameterswereconsideredasfollows: thepositionoftherecordingsiterelativetoeachblasthole,the delaytimebetweenthedetonationofeachtwoblastholeaccordingtotheactualinitiationnetworkand themeasuredpropagationvelocityofseismicwave.Thecalculatedresultsshowthatthedeveloped methodcanbeusedtopredicttheblastingvibrationvelocitypeaks,wholevibrationwaveform,vibrationdurationandmainfrequencydistribution. Andthecalculatedwaveformsarecoincidentwiththe recordedonesinthedeepholeblastingtestsusingelectronicdetonators.Itindicatesthatthedevelopedpredicationmethodisreliableforengineeringapplication.
Basedonthesuperpositionprincipleofseismicwaves,anewblastingvibrationwaveform predictionmodelwasproposedotherthanthetraditionalpredictionmethodsfoundedondatastatistics. Accordingtothemeasuredvibrationwaveformsfromsingleblastholes,thedevelopedmodel wasusedtocalculatetheblastingvibrationwaveformsatcertainlocations.Inthecalculation,theparameterswereconsideredasfollows: thepositionoftherecordingsiterelativetoeachblasthole,the delaytimebetweenthedetonationofeachtwoblastholeaccordingtotheactualinitiationnetworkand themeasuredpropagationvelocityofseismicwave.Thecalculatedresultsshowthatthedeveloped methodcanbeusedtopredicttheblastingvibrationvelocitypeaks,wholevibrationwaveform,vibrationdurationandmainfrequencydistribution. Andthecalculatedwaveformsarecoincidentwiththe recordedonesinthedeepholeblastingtestsusingelectronicdetonators.Itindicatesthatthedevelopedpredicationmethodisreliableforengineeringapplication.
2012, 32(1): 91-96.
doi: 10.11883/1001-1455(2012)01-0091-06
Abstract:
Assumingthematerialtobeincompressibleandusingappropriateplasticconstitutiverelations, thepartialdifferentialequationsgoverningthedynamicexpansionofacylindershellunderinternalpressurecanbereducedtoanordinarydiffer ntialequationtakingtheinternalradiusasthedependentvariable. SomemeaningfulresultsaregainedbynumericalanalysisonCu.Thestainrate hardeningimpedesthedynamicexpansionofthecylindershell,whereastheinfluenceofthestrain hardeningandthermaleffectscanbeneglected,whichisindependentoftheshellthickness.
Assumingthematerialtobeincompressibleandusingappropriateplasticconstitutiverelations, thepartialdifferentialequationsgoverningthedynamicexpansionofacylindershellunderinternalpressurecanbereducedtoanordinarydiffer ntialequationtakingtheinternalradiusasthedependentvariable. SomemeaningfulresultsaregainedbynumericalanalysisonCu.Thestainrate hardeningimpedesthedynamicexpansionofthecylindershell,whereastheinfluenceofthestrain hardeningandthermaleffectscanbeneglected,whichisindependentoftheshellthickness.
2012, 32(1): 97-102.
doi: 10.11883/1001-1455(2012)01-0097-06
Abstract:
Astudyofimpactdamagetorabbitiscarriedoutbyusingashocktubeimprovedfroma light-gasgundevice,atdifferentshockwavepressures.Basedonthemeasurementofthevariationof itsphysiologicalcharacteristicsandorgans (lung,kidneyetc.),theeffectsofshockresponseand damagecoregulationontheoverallphysiologicalsystemswereinvestigated.Theresultsshowedthe damageoflungincreaseswithincreasingshockwavepressure.Theratioofwettodryofinjuredlung increaseswithincreasingpressure.Weobtainedtherelationbetweenthisratioandtheshockwave pressure.Wefoundthebloodpressuresdecreaseswithincreasingshockwavepressure.Theshock wavehasasignificantimpactontheotherorgansbesidesthelung.
Astudyofimpactdamagetorabbitiscarriedoutbyusingashocktubeimprovedfroma light-gasgundevice,atdifferentshockwavepressures.Basedonthemeasurementofthevariationof itsphysiologicalcharacteristicsandorgans (lung,kidneyetc.),theeffectsofshockresponseand damagecoregulationontheoverallphysiologicalsystemswereinvestigated.Theresultsshowedthe damageoflungincreaseswithincreasingshockwavepressure.Theratioofwettodryofinjuredlung increaseswithincreasingpressure.Weobtainedtherelationbetweenthisratioandtheshockwave pressure.Wefoundthebloodpressuresdecreaseswithincreasingshockwavepressure.Theshock wavehasasignificantimpactontheotherorgansbesidesthelung.
2012, 32(1): 103-107.
doi: 10.11883/1001-1455(2012)01-0103-05
Abstract:
Byusing3 mmthicktitanium TA2and26 mmthicknormalizedsteelQ345R,explosive weldingexperimentswereperformed,andthedynamicparameterswerestudied.Inlightofthecharactersofbondingareaofthecladplate, bondstrength (shearstrength)andthemetallurgicalstructuresofinterfacewaves, theconditionsresponsibleforhighbondstrengthandmoreregularinterface wavemorphologywerediscussed.For3mmthicktitanium TA2and26mmthicknormalizedsteel Q345R,theconditionisthedynamicalbendangle17,anddynamicalimpactvelocityvp 760m/s.Themechanismresponsibleforinterfacewaveswasdiscussedaccordingtothemetallurgical structuresofinterfacewavesandthestriationofthebaseplate.Theconclusionisthatthejetprevents thecladplatefromcontinuouslyimpactingthebaseplate,whichisoneofthemainreasonswhythe interfacewaveisalwaysobserved.
Byusing3 mmthicktitanium TA2and26 mmthicknormalizedsteelQ345R,explosive weldingexperimentswereperformed,andthedynamicparameterswerestudied.Inlightofthecharactersofbondingareaofthecladplate, bondstrength (shearstrength)andthemetallurgicalstructuresofinterfacewaves, theconditionsresponsibleforhighbondstrengthandmoreregularinterface wavemorphologywerediscussed.For3mmthicktitanium TA2and26mmthicknormalizedsteel Q345R,theconditionisthedynamicalbendangle17,anddynamicalimpactvelocityvp 760m/s.Themechanismresponsibleforinterfacewaveswasdiscussedaccordingtothemetallurgical structuresofinterfacewavesandthestriationofthebaseplate.Theconclusionisthatthejetprevents thecladplatefromcontinuouslyimpactingthebaseplate,whichisoneofthemainreasonswhythe interfacewaveisalwaysobserved.
2012, 32(1): 108-112.
doi: 10.11883/1001-1455(2012)01-0108-05
Abstract:
Inordertounderstandthe mechanism ofliquidfuelclouddetonation,theup-and-down methodandsoottracetechniquewereusedtostudytherelationshipbetweentheclouddetonationparameters( velocity,pressure,criticalinitiationenergyandcellwidth)andequivalenceratioexperimentallywithaverticalshocktube. Resultsindicatedthatthedetonationpressureanddetonationvelocityofpropyleneoxide( PO)increasedandthendecreasedsmoothlywiththerisingofequivalence ratio.Thecriticalinitiationenergythatdirectlyinitiatedthedetonationofhydrocarbonliquidfuel cloudshowedaU-shapedcurverelationwiththevariationofequivalenceratios.Theoptimumconcentrationwasfoundonthesidewheretheequivalenceratioisover1. Thecriticalinitiationenergywas alsofoundcloselyrelatedtomolecularstructureandvolatilityoffuels.IPNandPOhadsimilarcriticalvaluesandthoseofalkaneswerealllarger. DetonationcellsizesofPOatboth25 ℃ and50 ℃ showedaU-shapedcurve.Theminimalcellwidthalsoliedonthesideofrich-fuel(1).ThedetonationreactionofPOatnormaltemperatureiscontrolledbygas- phasereaction.
Inordertounderstandthe mechanism ofliquidfuelclouddetonation,theup-and-down methodandsoottracetechniquewereusedtostudytherelationshipbetweentheclouddetonationparameters( velocity,pressure,criticalinitiationenergyandcellwidth)andequivalenceratioexperimentallywithaverticalshocktube. Resultsindicatedthatthedetonationpressureanddetonationvelocityofpropyleneoxide( PO)increasedandthendecreasedsmoothlywiththerisingofequivalence ratio.Thecriticalinitiationenergythatdirectlyinitiatedthedetonationofhydrocarbonliquidfuel cloudshowedaU-shapedcurverelationwiththevariationofequivalenceratios.Theoptimumconcentrationwasfoundonthesidewheretheequivalenceratioisover1. Thecriticalinitiationenergywas alsofoundcloselyrelatedtomolecularstructureandvolatilityoffuels.IPNandPOhadsimilarcriticalvaluesandthoseofalkaneswerealllarger. DetonationcellsizesofPOatboth25 ℃ and50 ℃ showedaU-shapedcurve.Theminimalcellwidthalsoliedonthesideofrich-fuel(1).ThedetonationreactionofPOatnormaltemperatureiscontrolledbygas- phasereaction.
