2013 Vol. 33, No. 6
column
Display Method:
2013, 33(6): 561-566.
doi: 10.11883/1001-1455(2013)06-0561-06
PDF 
Cited by
Abstract:
Basedonthetechniqueofthesphericaldivergentstresswaveexperimentsandthecirque electromagnetictestingmethodoftheparticlevelocity,thepropagationofsphericalstresswaveand theparticlevelocitiesinPMMAundertampedexplosionwereexperimentallyinvestigatedbychoosing aminiaturesphericalexplosiveof0.125gTNTequivalentasthesphericalexplosionsource.The resultsrevealthatthepeakvaluesoftheparticlevelocitiesanddisplacementsfollowexponentialattenuationlawsandthecorrespondingattenu tionindexesare1.34and1.28,respectively.Asthescaled distanceincreases,thenegativepeakvaluesoftheparticlevelocitiestrendtofirstincreaseandthen decrease.Astheradialstressislowerthan1GPa,therelationsoftheradialstresspeakwiththeparticlevelocitypeakunderthestrongdiscontinuityassumptionareconsistentwiththe- v Hugoniot curvesfromone-dimensionalstrainexperiments.Andinvertedfromthevariablemodulusmodelassumptionandtheparticlevelocitycurves, theelastic,bulkandshearmoduliofPMMAare(6.40 0.64),(7.120.71)and(2.370.24)GPa,respectively.
Basedonthetechniqueofthesphericaldivergentstresswaveexperimentsandthecirque electromagnetictestingmethodoftheparticlevelocity,thepropagationofsphericalstresswaveand theparticlevelocitiesinPMMAundertampedexplosionwereexperimentallyinvestigatedbychoosing aminiaturesphericalexplosiveof0.125gTNTequivalentasthesphericalexplosionsource.The resultsrevealthatthepeakvaluesoftheparticlevelocitiesanddisplacementsfollowexponentialattenuationlawsandthecorrespondingattenu tionindexesare1.34and1.28,respectively.Asthescaled distanceincreases,thenegativepeakvaluesoftheparticlevelocitiestrendtofirstincreaseandthen decrease.Astheradialstressislowerthan1GPa,therelationsoftheradialstresspeakwiththeparticlevelocitypeakunderthestrongdiscontinuityassumptionareconsistentwiththe- v Hugoniot curvesfromone-dimensionalstrainexperiments.Andinvertedfromthevariablemodulusmodelassumptionandtheparticlevelocitycurves, theelastic,bulkandshearmoduliofPMMAare(6.40 0.64),(7.120.71)and(2.370.24)GPa,respectively.
2013, 33(6): 567-573.
doi: 10.11883/1001-1455(2013)06-0567-07
Abstract:
Akindofdoubleconelinerwasdesigned,itsformationandpenetrationmechanismswere studiedbymeansofnumericalsimulationsandexperiments,thejetparametersofthelinerswithdifferentstructureswereanalyzedtoacquiretheoptimizedresultthroughtheorthogonaldesignmethod, andthepenetrationcapabilitiesoftheoptimizedlinerswereexploredbynumericalsimulationandexperimentalmethods. Resultsdisplaythatthelinercanform ashapedchargejet,anexplosively formedprojectileandaslug.Thesmallconeangle2canexerciseasignificantinfluenceonthehead velocityofthejet,andthelinerthicknesstandthelargeconeangle2canobviouslyaffecttheprojectilevelocity. Fortheoptimizedparametersoft=0.14cm,2=50,2=135andN=0.4or0.5, theheadvelocitiesofthejetscanreach6613and6839m/s,respectively;thevelocitiesoftheprojectilescanreach2247and2095m/ s,respectively;thepenetrationdepthscanreach8.24and8.31cm, respectively;andtheholesizescanreach2.12and2.08cm,respectively.Sothedesignedbiconical linerstructureisreasonable,bywhichcanensurethevelocityoftheshapedchargejetandgreatlyimprovethevelocityoftheexplosivelyformedprojectile. Thejetandtheprojectilecanpenetrateintothe targetsuccessively,bywhichachievesthedoubledamage.Andforalow-densitychargeandasmall standoff,thepenetrationeffectisideal.
Akindofdoubleconelinerwasdesigned,itsformationandpenetrationmechanismswere studiedbymeansofnumericalsimulationsandexperiments,thejetparametersofthelinerswithdifferentstructureswereanalyzedtoacquiretheoptimizedresultthroughtheorthogonaldesignmethod, andthepenetrationcapabilitiesoftheoptimizedlinerswereexploredbynumericalsimulationandexperimentalmethods. Resultsdisplaythatthelinercanform ashapedchargejet,anexplosively formedprojectileandaslug.Thesmallconeangle2canexerciseasignificantinfluenceonthehead velocityofthejet,andthelinerthicknesstandthelargeconeangle2canobviouslyaffecttheprojectilevelocity. Fortheoptimizedparametersoft=0.14cm,2=50,2=135andN=0.4or0.5, theheadvelocitiesofthejetscanreach6613and6839m/s,respectively;thevelocitiesoftheprojectilescanreach2247and2095m/ s,respectively;thepenetrationdepthscanreach8.24and8.31cm, respectively;andtheholesizescanreach2.12and2.08cm,respectively.Sothedesignedbiconical linerstructureisreasonable,bywhichcanensurethevelocityoftheshapedchargejetandgreatlyimprovethevelocityoftheexplosivelyformedprojectile. Thejetandtheprojectilecanpenetrateintothe targetsuccessively,bywhichachievesthedoubledamage.Andforalow-densitychargeandasmall standoff,thepenetrationeffectisideal.
2013, 33(6): 574-580.
doi: 10.11883/1001-1455(2013)06-0574-07
Abstract:
Deformation-timecurvesofsheetmetalpenetratedbythepolycarbonate(PC)projectiles withdifferentnoseshapeswereexperimentallyobtainedaswellastheprojectile-targetinteraction timesbyusinganair-jetloadingapparatus.ThefailurecharacteristicsofthePCprojectilesduring penetrationwereobserved,whichincludingfracture,initialdamageandnoseplasticdeformation.The deformationsofthetruncated-cone-tipPCprojectilesafterpenetrationwereanalyzedbyaphotoplastic method.AndtheDSGZconstitutivemodelwereembeddedintothefiniteelementcodeasausersubroutinetonumericallysimulatethepenetrationprocessofth PCprojectilesintothealuminiumtargets. Thesimulatedresultsareinagreementwiththeexperimentalones.
Deformation-timecurvesofsheetmetalpenetratedbythepolycarbonate(PC)projectiles withdifferentnoseshapeswereexperimentallyobtainedaswellastheprojectile-targetinteraction timesbyusinganair-jetloadingapparatus.ThefailurecharacteristicsofthePCprojectilesduring penetrationwereobserved,whichincludingfracture,initialdamageandnoseplasticdeformation.The deformationsofthetruncated-cone-tipPCprojectilesafterpenetrationwereanalyzedbyaphotoplastic method.AndtheDSGZconstitutivemodelwereembeddedintothefiniteelementcodeasausersubroutinetonumericallysimulatethepenetrationprocessofth PCprojectilesintothealuminiumtargets. Thesimulatedresultsareinagreementwiththeexperimentalones.
2013, 33(6): 581-586.
doi: 10.11883/1001-1455(2013)06-0581-06
Abstract:
Tostudythedynamicresponseofmaterialsundertensileloadingathighstrainrates,tensile- loadingexperimentswereconductedonoxygen-freecopperexpandingringsbyapplyinganewexpandingringexperimenttechnique. Theradialvelocitiesofthecopperexpandingringsduringtensile deformationweremeasuredbyVISARorFDI.TheempiricalJohnson-Cook(JC)constitutivemodel wasusedtosimulatetheexpandingprocessofoxygen-freecopperrings.Thecalculatedresultsareobviouslyhigherthantheexperimentalones. SoaregulativeJCmodelfortensiledeformation(RJC)was proposedtoimprovetheempiricalJCconstitutivemodel.IntheRJC model,anewindexterm of strainhardingwasaddedtodescribetheaccumulatedeffectinthedynamictensiledeformationprocess aswellasanewlineartermofstrainratetodescribethestrain-rateeffectundertensileloading.And theparametersoftheRJCmodelwereobtainedbyfittingtotheexperimentdata.ThefurthernumericalresultsshowthattheRJCmodelcandescribetheexpandingdeformationprocessoftheoxygen- freecopperrings.
Tostudythedynamicresponseofmaterialsundertensileloadingathighstrainrates,tensile- loadingexperimentswereconductedonoxygen-freecopperexpandingringsbyapplyinganewexpandingringexperimenttechnique. Theradialvelocitiesofthecopperexpandingringsduringtensile deformationweremeasuredbyVISARorFDI.TheempiricalJohnson-Cook(JC)constitutivemodel wasusedtosimulatetheexpandingprocessofoxygen-freecopperrings.Thecalculatedresultsareobviouslyhigherthantheexperimentalones. SoaregulativeJCmodelfortensiledeformation(RJC)was proposedtoimprovetheempiricalJCconstitutivemodel.IntheRJC model,anewindexterm of strainhardingwasaddedtodescribetheaccumulatedeffectinthedynamictensiledeformationprocess aswellasanewlineartermofstrainratetodescribethestrain-rateeffectundertensileloading.And theparametersoftheRJCmodelwereobtainedbyfittingtotheexperimentdata.ThefurthernumericalresultsshowthattheRJCmodelcandescribetheexpandingdeformationprocessoftheoxygen- freecopperrings.
2013, 33(6): 587-593.
doi: 10.11883/1001-1455(2013)06-0587-07
Abstract:
Aone-dimensionalshockmodelandathree-dimensionalcell-basedfiniteelementmodelare developedforthedynamiccrushingofametallicfoamrodstrikingarigidwall.Theshockmodelis proposedbyusingthecontinuum-basedstresswavetheoryandassumingarate-independent,rigidnonlinearhardeningplasticconstitutiverelationofthefoam, thenanimplicitexpressionfordeterminingtherelationbetweenthelocalstrainbehindtheshockfrontandtheimpacttimeisobtained. The cell-basedfiniteelementmodelofaclosed-cellaluminumfoamisconstructedbythethree-dimensional Voronoitechnique,anditsdynamiccrushingprocessissimulatedbyusingtheABAQUS/Explicit code.Theleastsquaresmethodisusedtocalculatethedeformationgradientandlocalstrainfield. Comparingwiththesimulationresults,theshockmodelpresentsgoodpredictionsofthestressand strainbehindtheshockfront.
Aone-dimensionalshockmodelandathree-dimensionalcell-basedfiniteelementmodelare developedforthedynamiccrushingofametallicfoamrodstrikingarigidwall.Theshockmodelis proposedbyusingthecontinuum-basedstresswavetheoryandassumingarate-independent,rigidnonlinearhardeningplasticconstitutiverelationofthefoam, thenanimplicitexpressionfordeterminingtherelationbetweenthelocalstrainbehindtheshockfrontandtheimpacttimeisobtained. The cell-basedfiniteelementmodelofaclosed-cellaluminumfoamisconstructedbythethree-dimensional Voronoitechnique,anditsdynamiccrushingprocessissimulatedbyusingtheABAQUS/Explicit code.Theleastsquaresmethodisusedtocalculatethedeformationgradientandlocalstrainfield. Comparingwiththesimulationresults,theshockmodelpresentsgoodpredictionsofthestressand strainbehindtheshockfront.
2013, 33(6): 594-600.
doi: 10.11883/1001-1455(2013)06-0594-07
Abstract:
Tounderstandthewholedevelopingprocessoftheflowfieldinasphericalexplosivevessel, thepressureandtemperatureattheinternalsurfaceofthevesselweremonitoredaswellasthestrain ofitsexternalsurface.Theexperimentalresultsshowthattheflowfieldinthevesseltendedtobe evenaftertheblastwavesreflectedthreetimes.Thestrainwavesoftheexternalsurfaceindicatethat theexplosiveproductsinthevesselobviouslyunderwentasecondaryreaction.Thestraingrowthappearedatallthemeasuringpositionsandthatwasthemostevidentatthemeasuringpositionopposite theentranceofthevessel,atwhichthegrowthcoefficientoftheaveragestrainpeakarrivedat2.88. Theprimaryvibrationofthevesselwasbreathvibration,andthefrequencyofthesecondaryprimary vibrationwasaboutonehalfasmuchasthatofbreathvibration.Thelargeststrainoftheouterwall ofthevesselwasabout2.510-3,thecorrespondinglargestequivalentstresswasabout80% higher thanthestaticyieldstressofthevesselmaterial,whilethevesseldidnotpresentclearplasticdeformation.
Tounderstandthewholedevelopingprocessoftheflowfieldinasphericalexplosivevessel, thepressureandtemperatureattheinternalsurfaceofthevesselweremonitoredaswellasthestrain ofitsexternalsurface.Theexperimentalresultsshowthattheflowfieldinthevesseltendedtobe evenaftertheblastwavesreflectedthreetimes.Thestrainwavesoftheexternalsurfaceindicatethat theexplosiveproductsinthevesselobviouslyunderwentasecondaryreaction.Thestraingrowthappearedatallthemeasuringpositionsandthatwasthemostevidentatthemeasuringpositionopposite theentranceofthevessel,atwhichthegrowthcoefficientoftheaveragestrainpeakarrivedat2.88. Theprimaryvibrationofthevesselwasbreathvibration,andthefrequencyofthesecondaryprimary vibrationwasaboutonehalfasmuchasthatofbreathvibration.Thelargeststrainoftheouterwall ofthevesselwasabout2.510-3,thecorrespondinglargestequivalentstresswasabout80% higher thanthestaticyieldstressofthevesselmaterial,whilethevesseldidnotpresentclearplasticdeformation.
2013, 33(6): 601-607.
doi: 10.11883/1001-1455(2013)06-0601-07
Abstract:
The ultra-high-performancecementitiouscomposites(UHPCC)with thecompressive strengthof120~250MPawerepreparedbyusingtheordinaryconcretemoldingprocessandthehot watercuringtreatment.ThebehaviorsoftheUHPCCwithexcellentstaticmechanicalpropertieswere researchedbymultipleimpactpenetrationtests.ThedamageoftheUHPCCtargetsduringpenetrationwasanalyzed. AndbasedonthemultiplepenetrationmodelproposedbyJ.T.Gomez,etal,an empiricalformulaofpenetrationdepthinrelationtothetargetcompressivestrengthwasmodifiedaccordingtotheexperimentaldata.
The ultra-high-performancecementitiouscomposites(UHPCC)with thecompressive strengthof120~250MPawerepreparedbyusingtheordinaryconcretemoldingprocessandthehot watercuringtreatment.ThebehaviorsoftheUHPCCwithexcellentstaticmechanicalpropertieswere researchedbymultipleimpactpenetrationtests.ThedamageoftheUHPCCtargetsduringpenetrationwasanalyzed. AndbasedonthemultiplepenetrationmodelproposedbyJ.T.Gomez,etal,an empiricalformulaofpenetrationdepthinrelationtothetargetcompressivestrengthwasmodifiedaccordingtotheexperimentaldata.
2013, 33(6): 608-612.
doi: 10.11883/1001-1455(2013)06-0608-05
Abstract:
Toprovidethereliablemechanicalparametersofthefusesduringpenetration,itisnecessarytostudythedecelerationoftheprojectiles. Thepenetrationtestwascarriedoutforareduced-scale advancedearthpenetrationwarhead(EPW)intoconcrete.Thedeceleration-timecurveoftheprojectilewasobtainedbyahardrecoverytechnique. Thetestingsystemfordecelerationishighlymodularized, includingatestingmodule,acircuitmodule,amemorymodule,apower-supplymoduleanda peripherycomputermodulefordataprocessing.Inthetestingmodule,thepiezoresistiveaccelerometerisfabricatedbytheMEMStechniqueanditworksinaWheatstonebridge. Theprojectilemassis about1.8kg,includingthedecelerationtestingequipmentloadedinit.Themaximumdiameterofthe projectilesis48mm,andthestrikingvelocityis1142m/s.Thedecelerationmagnitudeobtainedby theexperimentisapproximately20104g.
Toprovidethereliablemechanicalparametersofthefusesduringpenetration,itisnecessarytostudythedecelerationoftheprojectiles. Thepenetrationtestwascarriedoutforareduced-scale advancedearthpenetrationwarhead(EPW)intoconcrete.Thedeceleration-timecurveoftheprojectilewasobtainedbyahardrecoverytechnique. Thetestingsystemfordecelerationishighlymodularized, includingatestingmodule,acircuitmodule,amemorymodule,apower-supplymoduleanda peripherycomputermodulefordataprocessing.Inthetestingmodule,thepiezoresistiveaccelerometerisfabricatedbytheMEMStechniqueanditworksinaWheatstonebridge. Theprojectilemassis about1.8kg,includingthedecelerationtestingequipmentloadedinit.Themaximumdiameterofthe projectilesis48mm,andthestrikingvelocityis1142m/s.Thedecelerationmagnitudeobtainedby theexperimentisapproximately20104g.
2013, 33(6): 613-619.
doi: 10.11883/1001-1455(2013)06-0613-07
Abstract:
Aninnovativetestingtechniquecoupledbystaticanddynamicloadswasintroducedtoinvestigatethetypicaldynamicstress- straincurveoftherockspecimenundercyclicimpactloadingsaswell asthechangesofthereflectedandtransmittedwavespropagatinginit.Theresultsshowthatthesingletypicalstress- straincurveoftherockspecimenundercyclicimpactscanbedividedintofivestages: thecompactedstage,theelasticstage,theloadingstageoftheinternalcrackpropagation,thefirst unloadingstageandthesecondunloadingstage.Withtheincreaseinthenumberofimpact,theamplitudeofthereflectedwaveincreasesandthecorrespondingpeakvalueappearslater; theamplitude ofthetransmittedwavedecreasesandthecorrespondingpeakvalueoccurincreasinglyearlier,respectively. Itisdemonstratedthatthecyclicimpactsontherockspecimenareaccompaniedbythedamage accumulationresultinginthereducingofitsabilitytoresisttheexternalimpactloads.
Aninnovativetestingtechniquecoupledbystaticanddynamicloadswasintroducedtoinvestigatethetypicaldynamicstress- straincurveoftherockspecimenundercyclicimpactloadingsaswell asthechangesofthereflectedandtransmittedwavespropagatinginit.Theresultsshowthatthesingletypicalstress- straincurveoftherockspecimenundercyclicimpactscanbedividedintofivestages: thecompactedstage,theelasticstage,theloadingstageoftheinternalcrackpropagation,thefirst unloadingstageandthesecondunloadingstage.Withtheincreaseinthenumberofimpact,theamplitudeofthereflectedwaveincreasesandthecorrespondingpeakvalueappearslater; theamplitude ofthetransmittedwavedecreasesandthecorrespondingpeakvalueoccurincreasinglyearlier,respectively. Itisdemonstratedthatthecyclicimpactsontherockspecimenareaccompaniedbythedamage accumulationresultinginthereducingofitsabilitytoresisttheexternalimpactloads.
2013, 33(6): 620-624.
doi: 10.11883/1001-1455(2013)06-0620-05
Abstract:
Quasi-isentropiccompressiontechniquesdrivenbydetonationproductswithacavitywere usedtostudymaterialdynamicresponsecharacteristicsinweakshockornoshockconditions.Theentireexperimentsweresimulatedbyatwo- dimensionalprogram.Itwasproposedthatthechargediametershouldbelargeenoughtomaintaintheflyerplanebeforeimpact. Abackwardintegrationmethod wasusedforexperimentaldataprocessingandanalysis.
Quasi-isentropiccompressiontechniquesdrivenbydetonationproductswithacavitywere usedtostudymaterialdynamicresponsecharacteristicsinweakshockornoshockconditions.Theentireexperimentsweresimulatedbyatwo- dimensionalprogram.Itwasproposedthatthechargediametershouldbelargeenoughtomaintaintheflyerplanebeforeimpact. Abackwardintegrationmethod wasusedforexperimentaldataprocessingandanalysis.
2013, 33(6): 625-630.
doi: 10.11883/1001-1455(2013)06-0625-06
Abstract:
Abstract:Dynamiccompressionexperimentswereperformedwithamodifiedsplit-Hopkinsonpressurebartoexploretheeffectsofmoisturecontentonthedynamiccompressionpropertiesofunsaturatedclayundertheconstantstr in-rateloading.Theexperimentalresultsindicatethatwhenthewatercontentislow, thewateraddedintheclay,theradialformationofwhichisconfined,actsaslubricantandcanreducethefrictionbetweentheclayparticlessothattheunsaturatedlayiscompressed moreeasilythanthedryclay.Butwiththeincreasingofthewatercontent,thevoidsaregradually displacedbywater,makingitdifficultforclayparticlestodisplacetheinterstitialgaps,consequently, theclaymarkedlybecomesgoodinanti-compressionproperties.Andasthewatercontentincreases, thetotalenergyabsorbedbytheclaydecreases,inwhichtheportionofthevolumetricdeformation energyincreasesandtheportionofthedeviatoricdeformationenergydescends.
Abstract:Dynamiccompressionexperimentswereperformedwithamodifiedsplit-Hopkinsonpressurebartoexploretheeffectsofmoisturecontentonthedynamiccompressionpropertiesofunsaturatedclayundertheconstantstr in-rateloading.Theexperimentalresultsindicatethatwhenthewatercontentislow, thewateraddedintheclay,theradialformationofwhichisconfined,actsaslubricantandcanreducethefrictionbetweentheclayparticlessothattheunsaturatedlayiscompressed moreeasilythanthedryclay.Butwiththeincreasingofthewatercontent,thevoidsaregradually displacedbywater,makingitdifficultforclayparticlestodisplacetheinterstitialgaps,consequently, theclaymarkedlybecomesgoodinanti-compressionproperties.Andasthewatercontentincreases, thetotalenergyabsorbedbytheclaydecreases,inwhichtheportionofthevolumetricdeformation energyincreasesandtheportionofthedeviatoricdeformationenergydescends.
2013, 33(6): 631-637.
doi: 10.11883/1001-1455(2013)06-0631-07
Abstract:
Usingadynamiccausticsblastloadingsystem,thepaperstudiedthedynamicbehaviorof perforatedcrackpropagationbetweentwoholesandlateralcrackpropagationontheconditionofgroovingwithtwoboreholeblastingandsimultane usinitiation.Ascanbeseenfromtheresults,theperforatedcracktipsdidnotdirectlyencounter, butonewasatthetopandtheotherwasbelow,metand wentonpropagation,thengotclosertothedirectionoftheanisotropicexistingcrack.Thevelocity andaccelerationshowedatypeoffluctuationchangesaswave.Foronecrack,theaccelerationfirstly cametothepeak,thenthevelocitycametothepeak.ThedynamicstressintensityfactorKⅠ decreasedrapidlyfromthemaximum, oscillated,anduptothesecondpeak,thendecreased.KⅡ was almostsmallerthanKⅠ .Thestressintensityfactoroftheperforatedcracktipwasalmostgreater thanthatofthelateralcrack.Thedynamicenergyreleaseratedecreasedrapidly,oscillated,andthen decreased.
Usingadynamiccausticsblastloadingsystem,thepaperstudiedthedynamicbehaviorof perforatedcrackpropagationbetweentwoholesandlateralcrackpropagationontheconditionofgroovingwithtwoboreholeblastingandsimultane usinitiation.Ascanbeseenfromtheresults,theperforatedcracktipsdidnotdirectlyencounter, butonewasatthetopandtheotherwasbelow,metand wentonpropagation,thengotclosertothedirectionoftheanisotropicexistingcrack.Thevelocity andaccelerationshowedatypeoffluctuationchangesaswave.Foronecrack,theaccelerationfirstly cametothepeak,thenthevelocitycametothepeak.ThedynamicstressintensityfactorKⅠ decreasedrapidlyfromthemaximum, oscillated,anduptothesecondpeak,thendecreased.KⅡ was almostsmallerthanKⅠ .Thestressintensityfactoroftheperforatedcracktipwasalmostgreater thanthatofthelateralcrack.Thedynamicenergyreleaseratedecreasedrapidly,oscillated,andthen decreased.
2013, 33(6): 638-646.
doi: 10.11883/1001-1455(2013)06-0638-09
Abstract:
Themorphology,composition,structure,grainsize,surfacearea,porevolumeandpore sizeofthedetonationproductswerecharacterizedbyusingdifferenttechniquesincludingtheX-ray diffraction(XRD),thescanningelectron microscopy(SEM),theX-rayphotoelectronspectroscopy (EDS)andthespecificsurfaceareaandporosityanalysis.Theresultsshowthatthelatticeconstantof theeutecticmeltparticlesystemcomposedbysilverandasmallaccountofcopperissmallerthanthat ofthepuresilver.TheXRDanalysesindicatethatthegrainsizeofthesilverparticlesintheeutectic meltsystemis15.9~22.2nm.TheSEManalysesrevealthatthebiggerellipsoiddetonationproduct particlesconsistofsomesmallsmoothsphericalsilverparticlesanddifferentcomponents,theFeOin whichcomesfromthedetonationvessel,theamorphouscarbonfromtheorganicexplosivecombustioninthesealvessel, andtheAlandSifromthedetonationfacility.Themorphologyinvestigations agreewiththeXRDanalyses.Tomakeitclearthatthedetonationproductscontainingsomecarbon powderactastheroleofadsorption,thesurfacearea,porevolumeandporesizewerealsodiscussed.
Themorphology,composition,structure,grainsize,surfacearea,porevolumeandpore sizeofthedetonationproductswerecharacterizedbyusingdifferenttechniquesincludingtheX-ray diffraction(XRD),thescanningelectron microscopy(SEM),theX-rayphotoelectronspectroscopy (EDS)andthespecificsurfaceareaandporosityanalysis.Theresultsshowthatthelatticeconstantof theeutecticmeltparticlesystemcomposedbysilverandasmallaccountofcopperissmallerthanthat ofthepuresilver.TheXRDanalysesindicatethatthegrainsizeofthesilverparticlesintheeutectic meltsystemis15.9~22.2nm.TheSEManalysesrevealthatthebiggerellipsoiddetonationproduct particlesconsistofsomesmallsmoothsphericalsilverparticlesanddifferentcomponents,theFeOin whichcomesfromthedetonationvessel,theamorphouscarbonfromtheorganicexplosivecombustioninthesealvessel, andtheAlandSifromthedetonationfacility.Themorphologyinvestigations agreewiththeXRDanalyses.Tomakeitclearthatthedetonationproductscontainingsomecarbon powderactastheroleofadsorption,thesurfacearea,porevolumeandporesizewerealsodiscussed.
2013, 33(6): 647-654.
doi: 10.11883/1001-1455(2013)06-0647-08
Abstract:
TheJWLEOSparametersareveryimportantinnumericalsimulationsonexplosives,which canbeaffirmedfromcylinderexperiments.Butinactualcomputations,theseparametersmaydepart fromtheoriginalones.SoaimedtotheJWLEOSparameters,theuncertaintyquantificationwasexplored. ThedistributionofthemainparameterR1 wasgivenwithmathematicalandphysicalanalyses. Andtheuncertaintyquantificationanalysiswascarriedoutforthevelocityattheouterinterfaceofthe copperflyerdrivenbythePBX9404explosive.Theanalysismethodusedinthepaperish
TheJWLEOSparametersareveryimportantinnumericalsimulationsonexplosives,which canbeaffirmedfromcylinderexperiments.Butinactualcomputations,theseparametersmaydepart fromtheoriginalones.SoaimedtotheJWLEOSparameters,theuncertaintyquantificationwasexplored. ThedistributionofthemainparameterR1 wasgivenwithmathematicalandphysicalanalyses. Andtheuncertaintyquantificationanalysiswascarriedoutforthevelocityattheouterinterfaceofthe copperflyerdrivenbythePBX9404explosive.Theanalysismethodusedinthepaperish
2013, 33(6): 655-661.
doi: 10.11883/1001-1455(2013)06-0655-07
Abstract:
Basedontheone-dimensionalstresswavetheory,theelasticstresswavepropagationinthe splitHopkinsonpressurebar(SHPB)experimentwasanalyzedandthecalculationformulaforthe stressdistributioninthespecimenandthepressurebarwasobtained.Andsomefactorsinfluencing thetimeforthestressequilibriumwerediscussed.Theresultsshowthatthetimeforthestressequilibriumismarkedlyaffectedbythenominalspecimen- to-barimpedanceratioandtheincidentwaverisingtimeandhasnorelevancewiththespecimen- to-barsectionarearatioandtheincidentwavestress amplitude.BycombiningwiththeSHPBexperiment,thestrainchangecharacteristicsoftherock specimensachievingstressequilibrium wereinvestigatedfordifferentincidentstressamplitudesand variousincidentrisingtimes.Andsomemethodsforreducingstrainwereputforwardtomakesure thespecimenachievestressequilibriumbeforefracturetoensurethetestsvalid.TheconclusionsobtainedcanprovidesomereferencesforthedesignoftheSHPBexperimentsonbrittlematerialslike rock.
Basedontheone-dimensionalstresswavetheory,theelasticstresswavepropagationinthe splitHopkinsonpressurebar(SHPB)experimentwasanalyzedandthecalculationformulaforthe stressdistributioninthespecimenandthepressurebarwasobtained.Andsomefactorsinfluencing thetimeforthestressequilibriumwerediscussed.Theresultsshowthatthetimeforthestressequilibriumismarkedlyaffectedbythenominalspecimen- to-barimpedanceratioandtheincidentwaverisingtimeandhasnorelevancewiththespecimen- to-barsectionarearatioandtheincidentwavestress amplitude.BycombiningwiththeSHPBexperiment,thestrainchangecharacteristicsoftherock specimensachievingstressequilibrium wereinvestigatedfordifferentincidentstressamplitudesand variousincidentrisingtimes.Andsomemethodsforreducingstrainwereputforwardtomakesure thespecimenachievestressequilibriumbeforefracturetoensurethetestsvalid.TheconclusionsobtainedcanprovidesomereferencesforthedesignoftheSHPBexperimentsonbrittlematerialslike rock.
2013, 33(6): 662-666.
doi: 10.11883/1001-1455(2013)06-0662-05
Abstract:
Toexplorethedeformationfeaturesoftheplateswithholesunderblastwaves,thinplates oftwomaterialswerepreparedbyadoptingthreekindsofholenumbersandthreekindsofholediameterstogaintherulesofdeflectionatthecentreof heplates.Ageneralizeddeflectionformulawas proposedbycombiningtheexistentdeflectionformulafortheplateswithoutholessubjectedtoblast loading.Theproposeddeflectionformulacanbeusedtocalculatethedeflectionatthecentreofthe plateswithholes.
Toexplorethedeformationfeaturesoftheplateswithholesunderblastwaves,thinplates oftwomaterialswerepreparedbyadoptingthreekindsofholenumbersandthreekindsofholediameterstogaintherulesofdeflectionatthecentreof heplates.Ageneralizeddeflectionformulawas proposedbycombiningtheexistentdeflectionformulafortheplateswithoutholessubjectedtoblast loading.Theproposeddeflectionformulacanbeusedtocalculatethedeflectionatthecentreofthe plateswithholes.
2013, 33(6): 667-672.
doi: 10.11883/1001-1455(2013)06-0667-06
Abstract:
WiththehelpofthenonlinearfiniteelementcodeLS-DYNA,adiscretefiniteelementmodelwasdevelopedtonumericallysimulatethedynamicresponseofthereinforcedconcretecontainment underinternalblastloadingbyemployingafluid-structure-couplingalgorithm.AndthesimulatedresultswerecomparedwiththosebytheHenrychformulaaswellasonesintheTM5- 1300standard, respectively.Thecomparisonsindicatethatareliablesimulationcanbeachievedbythedeveloped modelforthereinforcedconcretecontainmentsubjectedtotheinternalexplosionunderthescaledistanceof3.258m/ kg1/3 whentheexplosionsourceis48mabovethecontainmentbase.
WiththehelpofthenonlinearfiniteelementcodeLS-DYNA,adiscretefiniteelementmodelwasdevelopedtonumericallysimulatethedynamicresponseofthereinforcedconcretecontainment underinternalblastloadingbyemployingafluid-structure-couplingalgorithm.AndthesimulatedresultswerecomparedwiththosebytheHenrychformulaaswellasonesintheTM5- 1300standard, respectively.Thecomparisonsindicatethatareliablesimulationcanbeachievedbythedeveloped modelforthereinforcedconcretecontainmentsubjectedtotheinternalexplosionunderthescaledistanceof3.258m/ kg1/3 whentheexplosionsourceis48mabovethecontainmentbase.
