2011 Vol. 31, No. 2
Display Method:
2011, 31(2): 113-118.
doi: 10.11883/1001-1455(2011)02-0113-06
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Abstract:
Carbonnitridepowderswith C N bondswerepreparedbytaking1,3,5-trinitro-1,3,5- triazacyclohexane(RDX)asthehigh-temperature,high-pressuresourceaswellasdicyandiamide (C2H4N4)astheprimaryprecursor.Themorphology,compositionandstructureoftheproducts werecharacterizedbyusingscanningelectronmicroscopy(SEM),X-raydiffraction(XRD),Fourier transforminfrared(FTIR)andX-rayphotoelectronspectroscopy(EDS).Theresultsshowthatall the C?N bondsandthegreatmassofthe CN bondsintheprecursoraredestroyedandturned intoC3N4crystalmainlywith C N bonds.XRDresultssuggestthattheproductincludes-C3N4, -C3N4andgraphite-C3N4crystals.Somehexagonalparticlesof2minsizeareobservedinthescanningelectronmicroscopy. Nitrogencontentintheproductscanbeeffectivelyimprovedbyadding5- aminotetrazole(CH3N5)inprecursors.
Carbonnitridepowderswith C N bondswerepreparedbytaking1,3,5-trinitro-1,3,5- triazacyclohexane(RDX)asthehigh-temperature,high-pressuresourceaswellasdicyandiamide (C2H4N4)astheprimaryprecursor.Themorphology,compositionandstructureoftheproducts werecharacterizedbyusingscanningelectronmicroscopy(SEM),X-raydiffraction(XRD),Fourier transforminfrared(FTIR)andX-rayphotoelectronspectroscopy(EDS).Theresultsshowthatall the C?N bondsandthegreatmassofthe CN bondsintheprecursoraredestroyedandturned intoC3N4crystalmainlywith C N bonds.XRDresultssuggestthattheproductincludes-C3N4, -C3N4andgraphite-C3N4crystals.Somehexagonalparticlesof2minsizeareobservedinthescanningelectronmicroscopy. Nitrogencontentintheproductscanbeeffectivelyimprovedbyadding5- aminotetrazole(CH3N5)inprecursors.
2011, 31(2): 119-126.
doi: 10.11883/1001-1455(2011)02-0119-08
Abstract:
Asymmetricalmassabrasionisoneofthedominantreasonstocauseaprojectilebending, yawingandbreakwhenitstrikesaconcretetargetnormallyathighvelocity.Thesphericalcavity-expansionmodelisemployedtoconstructthetransverseloadinthecaseofasymmetricalmassabrasion. Withconsideringtheaxisdragforcethatcanreflectthecontinuousvaryingofprojectilenoseshape,a methodisproposedtoanalyzetheyieldingofanormalpenetratingprojectileunderthecombinationof compressionandbendingduetoasymmetricalmassabrasion.Itindicatesthatthecriticalyielding cross-sectionofaprojectileisverymuchsensitivetothetransverseloadinducedbyasymmetricalmass abrasionwhenitsufferslargeaxisdragforce.
Asymmetricalmassabrasionisoneofthedominantreasonstocauseaprojectilebending, yawingandbreakwhenitstrikesaconcretetargetnormallyathighvelocity.Thesphericalcavity-expansionmodelisemployedtoconstructthetransverseloadinthecaseofasymmetricalmassabrasion. Withconsideringtheaxisdragforcethatcanreflectthecontinuousvaryingofprojectilenoseshape,a methodisproposedtoanalyzetheyieldingofanormalpenetratingprojectileunderthecombinationof compressionandbendingduetoasymmetricalmassabrasion.Itindicatesthatthecriticalyielding cross-sectionofaprojectileisverymuchsensitivetothetransverseloadinducedbyasymmetricalmass abrasionwhenitsufferslargeaxisdragforce.
2011, 31(2): 127-134.
doi: 10.11883/1001-1455(2011)02-0127-08
Abstract:
Numericalsimulationswereconductedonthepenetrationofthelongrodwiththelength-radialratioof5, theidealsegmentedrodandthesegmentedrodwithacarriertubeintosemi-infinite steeltargets,respectively,byusingthesoftwareANSYS/LS-DYNA3D.TheLagrangianmethodand Johnson-Cookconstitutivemodelwerecoupledinthenumericalsimulations.Thevon Misesestress contoursweregivenatthetypicaltimesduringthepenetrationandthepenetrationperformancesof theserodswerecompared.Comparisonshowsthatthedominantcontributiontothedepthofpenetration( DOP)ofthesegmentedrodisduetothephaseⅢnon-steadystageratherthanthephaseⅡquasi- steadypenetrationstageinthelong-rodpenetration.Theinterspacingofthesegmentedrodshasa significantimpactontheDOP,whilethecarriertubeonlycontributestotheincreaseofthecraterdiameter.
Numericalsimulationswereconductedonthepenetrationofthelongrodwiththelength-radialratioof5, theidealsegmentedrodandthesegmentedrodwithacarriertubeintosemi-infinite steeltargets,respectively,byusingthesoftwareANSYS/LS-DYNA3D.TheLagrangianmethodand Johnson-Cookconstitutivemodelwerecoupledinthenumericalsimulations.Thevon Misesestress contoursweregivenatthetypicaltimesduringthepenetrationandthepenetrationperformancesof theserodswerecompared.Comparisonshowsthatthedominantcontributiontothedepthofpenetration( DOP)ofthesegmentedrodisduetothephaseⅢnon-steadystageratherthanthephaseⅡquasi- steadypenetrationstageinthelong-rodpenetration.Theinterspacingofthesegmentedrodshasa significantimpactontheDOP,whilethecarriertubeonlycontributestotheincreaseofthecraterdiameter.
2011, 31(2): 135-140.
doi: 10.11883/1001-1455(2011)02-0135-06
Abstract:
Inashocktube,theair/SF6interfacewasacceleratedbytheincidentshockwavewiththe low Machnumberof1.27.Theinitialsinusoidalinterfacewasobtainedbyapplyingthepolymeric membranewiththethicknessof1~2mandtheinterfaceevolutionwasmonitoredbyusingthetimeresolvedshadowgraphtechnique. TheRichtmyer-Meshkov (RM)instabilityofthesinusoidalinitial perturbationattheair/SF6interfaceswascharacterizedbythespikesoftheheavyfluid(SF6)falling intothelightfluid(air)andthebubblesofthelightfluid(air)risingintotheheavyfluid(SF6). DuetotheRichtmyer-Meshkov (RM)instabilitycausedbythetangentialvelocitydifferenceatthe air/SF6interfaces,theheadsofthespikesoverturnedintomushroomshapesandsubsequently themushroompolesbrokeup.AndthisRMinstabilitycausedthespikestobreakup.TheexperimentaldisturbanceamplitudeisinagreementwiththeresultsbytheZhang- Sohn modelandPPM simulation.
Inashocktube,theair/SF6interfacewasacceleratedbytheincidentshockwavewiththe low Machnumberof1.27.Theinitialsinusoidalinterfacewasobtainedbyapplyingthepolymeric membranewiththethicknessof1~2mandtheinterfaceevolutionwasmonitoredbyusingthetimeresolvedshadowgraphtechnique. TheRichtmyer-Meshkov (RM)instabilityofthesinusoidalinitial perturbationattheair/SF6interfaceswascharacterizedbythespikesoftheheavyfluid(SF6)falling intothelightfluid(air)andthebubblesofthelightfluid(air)risingintotheheavyfluid(SF6). DuetotheRichtmyer-Meshkov (RM)instabilitycausedbythetangentialvelocitydifferenceatthe air/SF6interfaces,theheadsofthespikesoverturnedintomushroomshapesandsubsequently themushroompolesbrokeup.AndthisRMinstabilitycausedthespikestobreakup.TheexperimentaldisturbanceamplitudeisinagreementwiththeresultsbytheZhang- Sohn modelandPPM simulation.
2011, 31(2): 141-147.
doi: 10.11883/1001-1455(2011)02-0141-07
Abstract:
BasedontheAlekseevski-Tatemodel,thepresentpaperanalyzestheinterfacedefeatofa longrodinitspenetrationprocess,andthecorrespondingformulaeofvelocitydecayandmasserosion ofthelongrodarepresented.Theeffectsofvelocitydecayandroderosiononthelossofthekinetic energyofthelongrodarediscussed.Inparticular,aimedtothetruthofquasi-statictailvelocityof thelongrodintheinterfacedefeat,thesimplifiedandexplicitanalyticalexpressionsareformulatedto describethevariationofthedominatedparameterssuchasthevelocityandthemassoftherodwith time.Itisconvenientforengineeringapplications.
BasedontheAlekseevski-Tatemodel,thepresentpaperanalyzestheinterfacedefeatofa longrodinitspenetrationprocess,andthecorrespondingformulaeofvelocitydecayandmasserosion ofthelongrodarepresented.Theeffectsofvelocitydecayandroderosiononthelossofthekinetic energyofthelongrodarediscussed.Inparticular,aimedtothetruthofquasi-statictailvelocityof thelongrodintheinterfacedefeat,thesimplifiedandexplicitanalyticalexpressionsareformulatedto describethevariationofthedominatedparameterssuchasthevelocityandthemassoftherodwith time.Itisconvenientforengineeringapplications.
2011, 31(2): 148-152.
doi: 10.11883/1001-1455(2011)02-0148-05
Abstract:
Themodifiedgaptestsetupwasdesigned.Theinputpressureofacceptorexplosivewas measuredbyapplyingaPVDFgauge,andthemotionimagesofthefreesurfacewererecordedbyusingahigh- speedframecamera.Therelationbetweenthefree-surfaceparticlevelocityandinputpressureofexplosivewereobtainedandcomparedwiththecalculatedfree- surfaceparticlevelocityofunreactedexplosive. ComparisonshowsthatthechemicalreactionthresholdandignitionthresholdofexplosiveJO- 9159are1.33and1.98GPa,respectively.
Themodifiedgaptestsetupwasdesigned.Theinputpressureofacceptorexplosivewas measuredbyapplyingaPVDFgauge,andthemotionimagesofthefreesurfacewererecordedbyusingahigh- speedframecamera.Therelationbetweenthefree-surfaceparticlevelocityandinputpressureofexplosivewereobtainedandcomparedwiththecalculatedfree- surfaceparticlevelocityofunreactedexplosive. ComparisonshowsthatthechemicalreactionthresholdandignitionthresholdofexplosiveJO- 9159are1.33and1.98GPa,respectively.
2011, 31(2): 153-157.
doi: 10.11883/1001-1455(2011)02-0153-05
Abstract:
Tomastertheeffectofthemagneticfieldsproducedbythegiantmechanicalandelectricalequipmentsincoalminesonmethaneexplosion, experimentalinvestigationswereconductedtoexplore theinfluencesofthemagneticfieldsonexplosionwavepressureandflamepropagationvelocityof methaneexplosion.Andtheoreticalanalysiswascarriedouttodiscusstheeffectofthemagneticfields onheattransportation,masstransportationandreactionprocessofmethaneexplosionanditspropagation. Itshowsthatthemagneticfieldcanenhancemethaneexplosionintensityandincreaseflame propagationvelocity,explosionpressure.Themorethemagneticfieldintensity,themoremarkedly themagneticfieldaffectsmethaneexplosion.Themagneticfieldscanincreaseturbulencebyincreasingmasstransferaction, heattransferaction,convectioneffects,diffusioncoefficientandentropyof thereactionsystem,sothemagneticfieldscanincreaseflamecombustionvelocity,flamepropagation velocity,releasemoreenergyandincreaseshockwaveenergy,andthenpromotethemethaneexplosionanditspropagation.
Tomastertheeffectofthemagneticfieldsproducedbythegiantmechanicalandelectricalequipmentsincoalminesonmethaneexplosion, experimentalinvestigationswereconductedtoexplore theinfluencesofthemagneticfieldsonexplosionwavepressureandflamepropagationvelocityof methaneexplosion.Andtheoreticalanalysiswascarriedouttodiscusstheeffectofthemagneticfields onheattransportation,masstransportationandreactionprocessofmethaneexplosionanditspropagation. Itshowsthatthemagneticfieldcanenhancemethaneexplosionintensityandincreaseflame propagationvelocity,explosionpressure.Themorethemagneticfieldintensity,themoremarkedly themagneticfieldaffectsmethaneexplosion.Themagneticfieldscanincreaseturbulencebyincreasingmasstransferaction, heattransferaction,convectioneffects,diffusioncoefficientandentropyof thereactionsystem,sothemagneticfieldscanincreaseflamecombustionvelocity,flamepropagation velocity,releasemoreenergyandincreaseshockwaveenergy,andthenpromotethemethaneexplosionanditspropagation.
2011, 31(2): 158-164.
doi: 10.11883/1001-1455(2011)02-0158-07
Abstract:
Toexplorethedynamicresponseofasuper-largeoiltankaffectedbygaseousmixtureexplosion, impactexperimentswereconductedonfloating-roofoil-tank modelsimpactedbysteadyblast wave,whichwasinducedbythereactionofacetylene/airmixturespropagatingalongapipe,ininflammablemixturedetonationfacilities. Theoverpressureload,dynamicstrainandvibrationaccelerationhistoriesweremeasuredatthewallsoftheoil- tankmodels.Thedestructionmechanismsofthe large-scalefloating-roofoiltankunderblastloadingwereanalyzed.Inthedeformationprocessofthe tankstructuresubjectedtoinflammablegasexplosion,theinnerliquidisinducedtogeneratecompressivewavetointensivelycollidewiththewallofthetank, thebackwallpressuretransmittedby liquidcollisionisinthesameorderofmagnitudewiththeblastwavepressureonthefront,buttheactuationtimeoftheformerislonger. Meanwhile,thetopoftheoil-tankinnerwallontheblastsideis intensilestate,encountersthemaximumtensilestrain,andhastheweakestresistancetoexplosion andblastloadingforthewholestructure.
Toexplorethedynamicresponseofasuper-largeoiltankaffectedbygaseousmixtureexplosion, impactexperimentswereconductedonfloating-roofoil-tank modelsimpactedbysteadyblast wave,whichwasinducedbythereactionofacetylene/airmixturespropagatingalongapipe,ininflammablemixturedetonationfacilities. Theoverpressureload,dynamicstrainandvibrationaccelerationhistoriesweremeasuredatthewallsoftheoil- tankmodels.Thedestructionmechanismsofthe large-scalefloating-roofoiltankunderblastloadingwereanalyzed.Inthedeformationprocessofthe tankstructuresubjectedtoinflammablegasexplosion,theinnerliquidisinducedtogeneratecompressivewavetointensivelycollidewiththewallofthetank, thebackwallpressuretransmittedby liquidcollisionisinthesameorderofmagnitudewiththeblastwavepressureonthefront,buttheactuationtimeoftheformerislonger. Meanwhile,thetopoftheoil-tankinnerwallontheblastsideis intensilestate,encountersthemaximumtensilestrain,andhastheweakestresistancetoexplosion andblastloadingforthewholestructure.
2011, 31(2): 165-172.
doi: 10.11883/1001-1455(2011)02-0165-08
Abstract:
Aimedatthestatusofexplosioncompaction,whichwasnotthoroughintheorystudyand reliedmainlyonengineeringexperiencetodetermineblastparametersinconstructions,asoilexplosioncompactionmodelwasdevelopedwhichwasbasedonplasticmechanicsandmechanicsofexplosion. Therelationsbetweencompactioneffects(compactionrange,compactiondegree)andexplosive parameterswerederivedandverifiedbythefieldtests.Thesevenfieldtestswerecarriedoutinthe holeswiththediameterof48mmandthecorrespondingnon-couplingcoefficientswere2.000,1.714, 1.500,1.333,1.200,1.091and1.000,respectively.Andtheoreticalcalculationsandfieldtestresultswerecomparedbymeasuringthesoildensitybeforeandaftertheexplosion. Investigatedresults indicatethatinthecaseofnon-couplingcharge,thetheoreticalvalueofcompactioneffectincreases withtheincreaseofnon-couplingcoefficient,whiletheexperimentaldatafirstincreasesandthendecreases, arrivingatthemaximumforthenon-couplingcoefficientofaround1.200.Fortheclayey silt,thecompactioneffectwasmorestable,thelargestcompactionrangeattains70cmandthemaximumcompressionratiois1.055. Thedevelopedsoilcompactionformulasafterexplosionaremoreaccurateandtherelativeerrorislessthan6.00%, sothattheseformulascanbeappliedtoengineering practice
Aimedatthestatusofexplosioncompaction,whichwasnotthoroughintheorystudyand reliedmainlyonengineeringexperiencetodetermineblastparametersinconstructions,asoilexplosioncompactionmodelwasdevelopedwhichwasbasedonplasticmechanicsandmechanicsofexplosion. Therelationsbetweencompactioneffects(compactionrange,compactiondegree)andexplosive parameterswerederivedandverifiedbythefieldtests.Thesevenfieldtestswerecarriedoutinthe holeswiththediameterof48mmandthecorrespondingnon-couplingcoefficientswere2.000,1.714, 1.500,1.333,1.200,1.091and1.000,respectively.Andtheoreticalcalculationsandfieldtestresultswerecomparedbymeasuringthesoildensitybeforeandaftertheexplosion. Investigatedresults indicatethatinthecaseofnon-couplingcharge,thetheoreticalvalueofcompactioneffectincreases withtheincreaseofnon-couplingcoefficient,whiletheexperimentaldatafirstincreasesandthendecreases, arrivingatthemaximumforthenon-couplingcoefficientofaround1.200.Fortheclayey silt,thecompactioneffectwasmorestable,thelargestcompactionrangeattains70cmandthemaximumcompressionratiois1.055. Thedevelopedsoilcompactionformulasafterexplosionaremoreaccurateandtherelativeerrorislessthan6.00%, sothattheseformulascanbeappliedtoengineering practice
2011, 31(2): 173-178.
doi: 10.11883/1001-1455(2011)02-0173-06
Abstract:
Theunderwaterexplosionprocessofmineslyingonseabedwassimulatedbyusingthe meshfreeSPH method.Andthesubstanceinterfacesweretreatedbyadoptingtheimpedancematching method.Thereflectioncoefficientsofthepeakpressuresindifferentdirectionsatdifferentdistances fromtheexplosioncenterwereobtained.Thedistributionandchangeoftheexplosionfieldparameters wereanalyzed.Andtheeffectsofdifferentsandthicknessanddifferentchargemassonshockwave propagationandpressurewerediscussed.Simulationresultsshowthattheseabedreflectioncoefficient varieswiththeanglebetweenmeasuringpointsandhorizontallineanditarrivesatthemaximumvalueof1.5whentheangleisabout55degree. Itishelpfulfordeterminingtheexplosionloadofmines lyingonseabed.
Theunderwaterexplosionprocessofmineslyingonseabedwassimulatedbyusingthe meshfreeSPH method.Andthesubstanceinterfacesweretreatedbyadoptingtheimpedancematching method.Thereflectioncoefficientsofthepeakpressuresindifferentdirectionsatdifferentdistances fromtheexplosioncenterwereobtained.Thedistributionandchangeoftheexplosionfieldparameters wereanalyzed.Andtheeffectsofdifferentsandthicknessanddifferentchargemassonshockwave propagationandpressurewerediscussed.Simulationresultsshowthattheseabedreflectioncoefficient varieswiththeanglebetweenmeasuringpointsandhorizontallineanditarrivesatthemaximumvalueof1.5whentheangleisabout55degree. Itishelpfulfordeterminingtheexplosionloadofmines lyingonseabed.
2011, 31(2): 179-184.
doi: 10.11883/1001-1455(2011)02-0179-06
Abstract:
Indoorexplosivefracturingsimulationtestswerecarriedoutatatmosphericpressureand20 MPaconfiningpressure,respectively.Theobtainedexplosivefracturingeffectswerecompared.Comparisonsshowthatconfiningpressurehasacertaininfluenceoncrackpropagationpath, crackshape andcrackcurvature;andthatthenumberofcracksinducedbyexplosivefracturingat20MPaconfiningpressureisless, thelengthisshorterandthecurvatureisclearerthanthosegeneratedatatmosphericpressure. Thefractalpropertiesofthecracksweredescribedbythefractaltheoryandthefractaldimensionsofthosecrackswerederived. Resultsdisplaythatunderthesametestconditions,the fractaldimensionsofthecracksatthesurfaceofthesamecementsamplearenotcompletelythesame witheachother,andthatthefractaldimensionofthecracksat20 MPaconfiningpressureishigher thanthosegeneratedatatmosphericpressure.
Indoorexplosivefracturingsimulationtestswerecarriedoutatatmosphericpressureand20 MPaconfiningpressure,respectively.Theobtainedexplosivefracturingeffectswerecompared.Comparisonsshowthatconfiningpressurehasacertaininfluenceoncrackpropagationpath, crackshape andcrackcurvature;andthatthenumberofcracksinducedbyexplosivefracturingat20MPaconfiningpressureisless, thelengthisshorterandthecurvatureisclearerthanthosegeneratedatatmosphericpressure. Thefractalpropertiesofthecracksweredescribedbythefractaltheoryandthefractaldimensionsofthosecrackswerederived. Resultsdisplaythatunderthesametestconditions,the fractaldimensionsofthecracksatthesurfaceofthesamecementsamplearenotcompletelythesame witheachother,andthatthefractaldimensionofthecracksat20 MPaconfiningpressureishigher thanthosegeneratedatatmosphericpressure.
2011, 31(2): 185-190.
doi: 10.11883/1001-1455(2011)02-0185-06
Abstract:
Tovalidatethefeasibilityofhigh-speedignitionbydetonationandfindouttheignition mechanism,anexperimentalsystemwasdevelopedfortheinvestigationofdetonationignitionwithan in-lineexplosiveinitiator.Thepressurechangesinthetestfacilitiesafterignitionatspecificcharges weremeasuredbythissystem.Theignitiondelaytimewasachieved0.3msbytheignitionmethod. Thecharacteristicsofpowderburningandtheattentionsinpracticalapplicationswereobtainedbythe wayofignition,suchasthestructurestrengthofthetestfacilitiesclosetotheexplosionspot,theattenuationcourseofdetonationwaveandsoon. Themechanismofthehigh-speedignitionbydetonationwasanalyzed. Theinvestigatedresultscanprovidehelpforapplyingtheignitionbydetonationto engineering.
Tovalidatethefeasibilityofhigh-speedignitionbydetonationandfindouttheignition mechanism,anexperimentalsystemwasdevelopedfortheinvestigationofdetonationignitionwithan in-lineexplosiveinitiator.Thepressurechangesinthetestfacilitiesafterignitionatspecificcharges weremeasuredbythissystem.Theignitiondelaytimewasachieved0.3msbytheignitionmethod. Thecharacteristicsofpowderburningandtheattentionsinpracticalapplicationswereobtainedbythe wayofignition,suchasthestructurestrengthofthetestfacilitiesclosetotheexplosionspot,theattenuationcourseofdetonationwaveandsoon. Themechanismofthehigh-speedignitionbydetonationwasanalyzed. Theinvestigatedresultscanprovidehelpforapplyingtheignitionbydetonationto engineering.
2011, 31(2): 191-195.
doi: 10.11883/1001-1455(2011)02-0191-05
Abstract:
Waveletanalysisandindependentcomponentanalysis(ICA)wereintegrallyappliedtoinvestigatetheseparationofthemeasuredshort- delayblastingvibrationsignalsintwodrillingholes. Waveletanalysiswasusedtofilteroutthehigh-frequencysignalwithalowerenergyratiointheblastingvibrationsignalsandtoextractthereconstructedsignalsinthefrequencyrangwiththem infeatures. ThereconstructedsignalswereseparatedusingICA.Thesegmentalseismicwavesweresuccessfullyobtained, whichcouldreflectthepracticalsituation.Andtheactualshort-delayintervaltime ofthesegmentalseismicwaveswasdetermined.ItisindicatedthatICAishelpfulforblastingvibrationsignalprocessing.
Waveletanalysisandindependentcomponentanalysis(ICA)wereintegrallyappliedtoinvestigatetheseparationofthemeasuredshort- delayblastingvibrationsignalsintwodrillingholes. Waveletanalysiswasusedtofilteroutthehigh-frequencysignalwithalowerenergyratiointheblastingvibrationsignalsandtoextractthereconstructedsignalsinthefrequencyrangwiththem infeatures. ThereconstructedsignalswereseparatedusingICA.Thesegmentalseismicwavesweresuccessfullyobtained, whichcouldreflectthepracticalsituation.Andtheactualshort-delayintervaltime ofthesegmentalseismicwaveswasdetermined.ItisindicatedthatICAishelpfulforblastingvibrationsignalprocessing.
2011, 31(2): 196-203.
doi: 10.11883/1001-1455(2011)02-0196-08
Abstract:
Theseismicdataoflow-yieldexplosionearthquakeswhichtookplaceintheQuaternaryperiodsoilwerebasedontocalculatetheparticlevelocitiesofthelongitudinalan transversalwavesand determinetheparametersfortheexistentmodels.Thethreerepresentativemodelsweresynthetically analyzed.Itdisplaysthatthedifferenceoftheexistentmodelsliesindifferentyieldexponents.Accordingly, adouble-extrememodelwasproposedandthecalculationmethodofthemodelparameters wasintroducedindetail.Comparisonofthesemodelsshowsthatthedatacalculatedbythedouble-extrememodelisthemostconsistentwiththerealobservationandtheamplitudeerrorbetweenthemis thesmallest.Thebestresultscalculatedbythetraditionalvelocitymodelsonlyapproachthesecalculatedbythedouble- extrememodel.
Theseismicdataoflow-yieldexplosionearthquakeswhichtookplaceintheQuaternaryperiodsoilwerebasedontocalculatetheparticlevelocitiesofthelongitudinalan transversalwavesand determinetheparametersfortheexistentmodels.Thethreerepresentativemodelsweresynthetically analyzed.Itdisplaysthatthedifferenceoftheexistentmodelsliesindifferentyieldexponents.Accordingly, adouble-extrememodelwasproposedandthecalculationmethodofthemodelparameters wasintroducedindetail.Comparisonofthesemodelsshowsthatthedatacalculatedbythedouble-extrememodelisthemostconsistentwiththerealobservationandtheamplitudeerrorbetweenthemis thesmallest.Thebestresultscalculatedbythetraditionalvelocitymodelsonlyapproachthesecalculatedbythedouble- extrememodel.
2011, 31(2): 204-209.
doi: 10.11883/1001-1455(2011)02-0204-06
Abstract:
Aimedatformingmultimodepenetratorswiththesameshapedcharge,theLS-DYNAsoftwarewasusedtoexploretheeffectsofthepointinitiationpositionontheformationofanexplosively formedpenetrator(EFP).Whentheaxisdistancebetweenthelinerandtheinitiationpointincreased from0to0.72timesaslongasthechargecaliber,theEFPvelocityincreased37.8percentandthe length-diameterratioincreasedover100percent.Thechargeshapewasoptimized.Thediffusionof thedetonationwaveswasanalyzed,whichwereformedbythecenterpointinitiationattheendofthe chargeandthepointinitiationofthelinerpeak,respectively.Andtheconversionoftherod-shaped EFPandEFPwasachieved.ThesimulatedresultsaccordwiththeX-rayimagingexperiments.
Aimedatformingmultimodepenetratorswiththesameshapedcharge,theLS-DYNAsoftwarewasusedtoexploretheeffectsofthepointinitiationpositionontheformationofanexplosively formedpenetrator(EFP).Whentheaxisdistancebetweenthelinerandtheinitiationpointincreased from0to0.72timesaslongasthechargecaliber,theEFPvelocityincreased37.8percentandthe length-diameterratioincreasedover100percent.Thechargeshapewasoptimized.Thediffusionof thedetonationwaveswasanalyzed,whichwereformedbythecenterpointinitiationattheendofthe chargeandthepointinitiationofthelinerpeak,respectively.Andtheconversionoftherod-shaped EFPandEFPwasachieved.ThesimulatedresultsaccordwiththeX-rayimagingexperiments.
2011, 31(2): 210-214.
doi: 10.11883/1001-1455(2011)02-0210-05
Abstract:
Ashock-tubecalibrationplatformwasestablishedtosolvetheinsufficientdynamicresponse ofapressurebartestsystemintheshockwavemeasurementforchemicalexplosiveexperiments.The dynamiccharacteristicsofthepressurebartestsystem wasinvestigatedbyadoptingthefollowing methodssuchassystemidentification,dynamiccompensationandthecombinationoftimedomainanalysisandfrequencydomainestimation. Anew-typedynamiccompensationfilterwasdesignedto improvethedynamiccharacteristicsofthetestsystem.Andthecompensationeffectwastested.The resultsshowthatthefrequencybandwidthofthetestsystemisexpandedandtheresponsetimeisreduced.
Ashock-tubecalibrationplatformwasestablishedtosolvetheinsufficientdynamicresponse ofapressurebartestsystemintheshockwavemeasurementforchemicalexplosiveexperiments.The dynamiccharacteristicsofthepressurebartestsystem wasinvestigatedbyadoptingthefollowing methodssuchassystemidentification,dynamiccompensationandthecombinationoftimedomainanalysisandfrequencydomainestimation. Anew-typedynamiccompensationfilterwasdesignedto improvethedynamiccharacteristicsofthetestsystem.Andthecompensationeffectwastested.The resultsshowthatthefrequencybandwidthofthetestsystemisexpandedandtheresponsetimeisreduced.
2011, 31(2): 215-219.
doi: 10.11883/1001-1455(2011)02-0215-05
Abstract:
Toexplorethedynamicmechanicalcharacteristicsofice,uniaxialcompressiontestswere carriedoutinthestrainraterangefrom500to2000s-1 byusingthesplitHopkinsonpressurebar (SHPB)techniqueat-25and-10 ℃,respectively.Moldsweredesignedtomanufactureicesamples, andacoolingchamberwasdevelopedtomeetthelow-temperaturecondition.Pulseshaperswere usedtoachieveconstantstrainrateloading.Experimentalresultsshowthatthedynamicstress-strain relationoficeisnonlinear,thepeakstressandfailurestrainincreasewiththeincreaseofstrainrates, andthecompressivestrengthoficedecreaseswiththeincreaseofthetesttemperature.
Toexplorethedynamicmechanicalcharacteristicsofice,uniaxialcompressiontestswere carriedoutinthestrainraterangefrom500to2000s-1 byusingthesplitHopkinsonpressurebar (SHPB)techniqueat-25and-10 ℃,respectively.Moldsweredesignedtomanufactureicesamples, andacoolingchamberwasdevelopedtomeetthelow-temperaturecondition.Pulseshaperswere usedtoachieveconstantstrainrateloading.Experimentalresultsshowthatthedynamicstress-strain relationoficeisnonlinear,thepeakstressandfailurestrainincreasewiththeincreaseofstrainrates, andthecompressivestrengthoficedecreaseswiththeincreaseofthetesttemperature.
2011, 31(2): 220-224.
doi: 10.11883/1001-1455(2011)02-0220-05
Abstract:
Two-dimensionalnumericalsimulationofdetonationwaveinterferenceamongperforating bulletswasmadebyemployingtheexplicitdynamicfiniteelementprogram.Effectsoftheprojectile bodyondetonationwaveinterferenceamongperforatingbulletswereconsidered.Andtheresultsof numericalsimulationwerediscussed.Themaincauseofinterferenceamongcharges,whichaffected perforationresultinhighshotdensityperforatingtechnology,wastheinterferedpressurefieldof blastwaveanddamageddetonationwave,whichwasdesignedinitially.Theresultsofnumericalsimulationareinagreementwithpreviousphysicalphenomenaandlaws. Thestudyindicatesthatthecalculationmodelandsimulationmethodarereasonableandfeasible, whichcanbeappliedtotheoptimizingdesignforgun- perforatorofhighshotdensity.
Two-dimensionalnumericalsimulationofdetonationwaveinterferenceamongperforating bulletswasmadebyemployingtheexplicitdynamicfiniteelementprogram.Effectsoftheprojectile bodyondetonationwaveinterferenceamongperforatingbulletswereconsidered.Andtheresultsof numericalsimulationwerediscussed.Themaincauseofinterferenceamongcharges,whichaffected perforationresultinhighshotdensityperforatingtechnology,wastheinterferedpressurefieldof blastwaveanddamageddetonationwave,whichwasdesignedinitially.Theresultsofnumericalsimulationareinagreementwithpreviousphysicalphenomenaandlaws. Thestudyindicatesthatthecalculationmodelandsimulationmethodarereasonableandfeasible, whichcanbeappliedtotheoptimizingdesignforgun- perforatorofhighshotdensity.
