2012 Vol. 32, No. 6
Display Method:
2012, 32(6): 561-567.
doi: 10.11883/1001-1455(2012)06-0561-07
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Abstract:
Experimentswerecarriedouttostudythedynamicresponseoftheliquid-filledthin-wall hemisphericalshellunderimpactusingtheDHR9401drophammerastheloadingdevice.According totheconfigurationsofthehemisphericalshells,theexperimentaldevicewaselaboratelydesignedto achievetheidealsealforfillingliquid.Thetimehistoriesoftheimpactforceandtheinternalpressure wererecordedfordifferenthemisphericalshells.Fourdistinctdeformationmodesofthehemispherical shellsunderimpactwereobservedasfollows:(1)flatteningoftheupwardlyprotrudingpoints,(2) inwarddimplingwithplastichingesfollowedbyoutwardexpanding,(3)flatteningoftheplasticedge regions,and(4)elasticrecovering.Theexperimentalresultsshowthatdouble-wallliquid-filledhemisphericalshellshavebetterimpactresistancethanthesingle- wallhemisphericalshells,fortheliquid filledcanreducethedeformationoftheinternalshellbyturningpointimpactintoevensurfaceimpact undertheexperimentalimpactconditions.Sothedoubleor multi-layerliquid-filledhemispherical shellscanprovidesatisfyingprotectionunderacertainimpactloading.
Experimentswerecarriedouttostudythedynamicresponseoftheliquid-filledthin-wall hemisphericalshellunderimpactusingtheDHR9401drophammerastheloadingdevice.According totheconfigurationsofthehemisphericalshells,theexperimentaldevicewaselaboratelydesignedto achievetheidealsealforfillingliquid.Thetimehistoriesoftheimpactforceandtheinternalpressure wererecordedfordifferenthemisphericalshells.Fourdistinctdeformationmodesofthehemispherical shellsunderimpactwereobservedasfollows:(1)flatteningoftheupwardlyprotrudingpoints,(2) inwarddimplingwithplastichingesfollowedbyoutwardexpanding,(3)flatteningoftheplasticedge regions,and(4)elasticrecovering.Theexperimentalresultsshowthatdouble-wallliquid-filledhemisphericalshellshavebetterimpactresistancethanthesingle- wallhemisphericalshells,fortheliquid filledcanreducethedeformationoftheinternalshellbyturningpointimpactintoevensurfaceimpact undertheexperimentalimpactconditions.Sothedoubleor multi-layerliquid-filledhemispherical shellscanprovidesatisfyingprotectionunderacertainimpactloading.
2012, 32(6): 568-572.
doi: 10.11883/1001-1455(2012)06-0568-05
Abstract:
Toimprovethecomputingefficiencyofthetraditionalantcolonyclusteringalgorithm,from datacombinationmechanism,anabstractionantcolonyclusteringalgorithmwasproposed.Byanalyzingthedataofrockburstsamples, fromtheengineeringanalogythinkingbytheabstractionantcolonyclusteringalgorithm, anew methodforforecastingofrockburstindeepundergroundengineering wasgiven.Somerockburstengineeringapplicationsofdeepminesprovethatcomparedwithtraditionalantcolonyclusteringalgorithm, forsimilarcomputingdifficultyandcomplexity,thevalidityof thenewalgorithm whoseaccuracyis92%,ishigher,andthecomputingvelocitycanincrease40%. Sotheabstractionantcolonyclusteringalgorithmispracticalforrockburstforecasting.
Toimprovethecomputingefficiencyofthetraditionalantcolonyclusteringalgorithm,from datacombinationmechanism,anabstractionantcolonyclusteringalgorithmwasproposed.Byanalyzingthedataofrockburstsamples, fromtheengineeringanalogythinkingbytheabstractionantcolonyclusteringalgorithm, anew methodforforecastingofrockburstindeepundergroundengineering wasgiven.Somerockburstengineeringapplicationsofdeepminesprovethatcomparedwithtraditionalantcolonyclusteringalgorithm, forsimilarcomputingdifficultyandcomplexity,thevalidityof thenewalgorithm whoseaccuracyis92%,ishigher,andthecomputingvelocitycanincrease40%. Sotheabstractionantcolonyclusteringalgorithmispracticalforrockburstforecasting.
2012, 32(6): 573-580.
doi: 10.11883/1001-1455(2012)06-0573-08
Abstract:
Basedonthedynamicsphericalcavity-expansiontheoryandthetwo-stagepenetrationmodel consistingofcrateringandtunneling,adimensionlessformulawasproposedfornormalpenetration depthofrigidprojectilesintoconcreteandrocktargetsbytakingatruncated-ogivenoseprojectileas anexample.Intheproposedformula,thesurfaceintegrationmethodwasapplied,andthemassratio andtheimpactfactorwereintroduced,aswellasthedimensionlesscoefficientsdenotingtheprojectile nosegeometryandtheprojectile-targetfrictioneffect,toconsiderthevariationofprojectilenosegeometry, crateringdepth,andtangentialresistanceonprojectiles.Andtheproposedformulacanberegressedtotheclassicpenetrationformulaeinspecialcases. Theproposedformulawasvalidatedby comparingthepenetrationdepthspredictedbytheproposedformulawiththosepredictedbytheexistingtenclassicempiricalandsemi- empiricalformulaeaswellastheexperimentaldatafromeightfield shottestsofconcreteandrocktargetshitbyprojectileswithdifferentnosegeometries.Basedonthe testsandparametricanalyses,thecorrespondingparametervalueswererecommendedaimingtodifferentnoseprojectiles, includingthedynamicprojectile-targetfrictionalcoefficientofconcreteand rocktargets,aswellasthelinearcoefficientofcrateringdepthrelatedtotheimpactfactor.
Basedonthedynamicsphericalcavity-expansiontheoryandthetwo-stagepenetrationmodel consistingofcrateringandtunneling,adimensionlessformulawasproposedfornormalpenetration depthofrigidprojectilesintoconcreteandrocktargetsbytakingatruncated-ogivenoseprojectileas anexample.Intheproposedformula,thesurfaceintegrationmethodwasapplied,andthemassratio andtheimpactfactorwereintroduced,aswellasthedimensionlesscoefficientsdenotingtheprojectile nosegeometryandtheprojectile-targetfrictioneffect,toconsiderthevariationofprojectilenosegeometry, crateringdepth,andtangentialresistanceonprojectiles.Andtheproposedformulacanberegressedtotheclassicpenetrationformulaeinspecialcases. Theproposedformulawasvalidatedby comparingthepenetrationdepthspredictedbytheproposedformulawiththosepredictedbytheexistingtenclassicempiricalandsemi- empiricalformulaeaswellastheexperimentaldatafromeightfield shottestsofconcreteandrocktargetshitbyprojectileswithdifferentnosegeometries.Basedonthe testsandparametricanalyses,thecorrespondingparametervalueswererecommendedaimingtodifferentnoseprojectiles, includingthedynamicprojectile-targetfrictionalcoefficientofconcreteand rocktargets,aswellasthelinearcoefficientofcrateringdepthrelatedtotheimpactfactor.
2012, 32(6): 581-584.
doi: 10.11883/1001-1455(2012)06-0581-04
Abstract:
Intheexperiments,theSiCl4liquidwiththepurityof99percentwaschosenasaprecursor andthegasmixturesofH2andO2asexplosionsources.Therelativemolarquantityoftheprecursor waschangedanditsinfluencesontheproductswereexplored.Andthenano-SiO2powderswerecharacterizedwithX- rayfluorescence(XRF)spectrometry,X-raydiffraction(XRD)andtransmissionelectronmicroscopy( TEM).TheXRFmeasurementshowsthattheobtainedproductismainlySiO2 anditspurityisabove99.9percent.TherelietypicalhalopatternsintheXRDspectraoftheproducts nearthediffractionangleof22degrees,indicatingthattheobtainedproductshaveamorphousstructures. The TEM images displaythatthe obtained main SiO2 powders have particlesizes of 50-100nmandarespherical.Withtheincreaseoftherelativemolarquantityoftheprecursor,the productsaregraduallyapttobondingandtheirdispersiondecreases.Sothemolarratiooftheprecursorshouldbecontrolledbelow1.25.
Intheexperiments,theSiCl4liquidwiththepurityof99percentwaschosenasaprecursor andthegasmixturesofH2andO2asexplosionsources.Therelativemolarquantityoftheprecursor waschangedanditsinfluencesontheproductswereexplored.Andthenano-SiO2powderswerecharacterizedwithX- rayfluorescence(XRF)spectrometry,X-raydiffraction(XRD)andtransmissionelectronmicroscopy( TEM).TheXRFmeasurementshowsthattheobtainedproductismainlySiO2 anditspurityisabove99.9percent.TherelietypicalhalopatternsintheXRDspectraoftheproducts nearthediffractionangleof22degrees,indicatingthattheobtainedproductshaveamorphousstructures. The TEM images displaythatthe obtained main SiO2 powders have particlesizes of 50-100nmandarespherical.Withtheincreaseoftherelativemolarquantityoftheprecursor,the productsaregraduallyapttobondingandtheirdispersiondecreases.Sothemolarratiooftheprecursorshouldbecontrolledbelow1.25.
2012, 32(6): 585-591.
doi: 10.11883/1001-1455(2012)06-0585-07
Abstract:
Inordertoinvestigatetheelastic-plasticbulkingofasubmarine,anexistentsimplifiedmodelforasubmarine, namelythering-stiffenedcylindricalshell,waschosenasthesimulationobject, andafluid-solidcouplingmodelwasbuiltbyusingthenonlinear,explicittransientdynamiccode, MSC.Dytrantoexploretheelastic-plasticbulkingofthering-stiffenedcylindricalshellsubjectedto underwaterexplosionload.ThecriticaldynamicbulkingloadwasobtainedbyusingtheBudiansky- RothruleandtheSouthwellmethod.Andthefollowingfactorswerediscussed:loadintensity,mesh density,radius-to-thicknessratio,length-to-radiusratio,ribspacingandribsizewhichinfluencing thedynamicbucklingmodeandthecriticalbucklingloadofthering-stiffenedcylindricalshellsubjectedtounderwaterexplosiveloading. Thesimulatedresultsshowthatthebuiltfluid-solidcoupling modelcanbeusedtosimulatethedynamicbulkingofthering-stiffenedcylindricalshellbycombining MSC.Dytran.Andthemodelmeshsizeandthestructuralparametershaveacertaininfluenceonthe criticaldynamicbucklingload,inwhichtheradius-to-thicknessratiohasmoreobviousinfluence.
Inordertoinvestigatetheelastic-plasticbulkingofasubmarine,anexistentsimplifiedmodelforasubmarine, namelythering-stiffenedcylindricalshell,waschosenasthesimulationobject, andafluid-solidcouplingmodelwasbuiltbyusingthenonlinear,explicittransientdynamiccode, MSC.Dytrantoexploretheelastic-plasticbulkingofthering-stiffenedcylindricalshellsubjectedto underwaterexplosionload.ThecriticaldynamicbulkingloadwasobtainedbyusingtheBudiansky- RothruleandtheSouthwellmethod.Andthefollowingfactorswerediscussed:loadintensity,mesh density,radius-to-thicknessratio,length-to-radiusratio,ribspacingandribsizewhichinfluencing thedynamicbucklingmodeandthecriticalbucklingloadofthering-stiffenedcylindricalshellsubjectedtounderwaterexplosiveloading. Thesimulatedresultsshowthatthebuiltfluid-solidcoupling modelcanbeusedtosimulatethedynamicbulkingofthering-stiffenedcylindricalshellbycombining MSC.Dytran.Andthemodelmeshsizeandthestructuralparametershaveacertaininfluenceonthe criticaldynamicbucklingload,inwhichtheradius-to-thicknessratiohasmoreobviousinfluence.
2012, 32(6): 592-598.
doi: 10.11883/1001-1455(2012)06-0592-07
Abstract:
Directinitiationwasachievedviaahigh-voltagecapacitorsparkdischargeandthecriticalenergywasaccuratelyestimatedfromtheanalysisofthecurrentoutput. Experimentswerecarriedout tomeasurethecriticalenergiesofC2H2-O2-ArandC2H2-N2O-Armixturesunderdifferentinitialconditions. ThecriticalenergiesforC2H2-N2O-ArmixturesaresignificantlyhigherthanthoseforC2H2- O2-Armixturesunderthesameinitialconditions.Therelationbetweenexplosionlengthandcritical tubediameterwasanalyzedtoexplorethelargediscrepancyofthecriticalenergybetweenthosemixtures. ThecriticaltubediametermeasurementinC2H2-N2O-Armixtureswasfurtherinvestigated, andbasedonthecriticaltubediametercorrelation,therelationshipbetweenexplosionlengthandcriticaltubediameterforC2H2- O2-Armixtureswasfoundtober0=2.5dc.Andthecorrespondingrelationshipisr0= 2dcforC2H2-O2-Armixtures.ItdisplaysthattheproportionalfactorbetweenexplosionlengthandcriticaltubediameterwillincreaseifN2Oisusedasanoxidizer, whichresultsinmore initiationenergyperunitrequiredforinitiatingthemixturetoachieveadirectdetonation.Thusthe criticalenergyofdirectinitiationtendstobehigher.
Directinitiationwasachievedviaahigh-voltagecapacitorsparkdischargeandthecriticalenergywasaccuratelyestimatedfromtheanalysisofthecurrentoutput. Experimentswerecarriedout tomeasurethecriticalenergiesofC2H2-O2-ArandC2H2-N2O-Armixturesunderdifferentinitialconditions. ThecriticalenergiesforC2H2-N2O-ArmixturesaresignificantlyhigherthanthoseforC2H2- O2-Armixturesunderthesameinitialconditions.Therelationbetweenexplosionlengthandcritical tubediameterwasanalyzedtoexplorethelargediscrepancyofthecriticalenergybetweenthosemixtures. ThecriticaltubediametermeasurementinC2H2-N2O-Armixtureswasfurtherinvestigated, andbasedonthecriticaltubediametercorrelation,therelationshipbetweenexplosionlengthandcriticaltubediameterforC2H2- O2-Armixtureswasfoundtober0=2.5dc.Andthecorrespondingrelationshipisr0= 2dcforC2H2-O2-Armixtures.ItdisplaysthattheproportionalfactorbetweenexplosionlengthandcriticaltubediameterwillincreaseifN2Oisusedasanoxidizer, whichresultsinmore initiationenergyperunitrequiredforinitiatingthemixturetoachieveadirectdetonation.Thusthe criticalenergyofdirectinitiationtendstobehigher.
2012, 32(6): 599-604.
doi: 10.11883/1001-1455(2012)06-0599-05
Abstract:
LS-DYNAwasusedtosimulatetheresponsesofdifferentreinforcedstructuressubjectedto underwatercontactexplosionbyconsideringdifferentreinforcementstrengthsandlocations.Strength anddistancefactorsweredefinedtodescribethestrengthandlocationsofstiffeners,respectively.Six modelswereproposedwithdifferentstrengthsofstiffenersandthreemodelsweredevelopedwithdifferentlocationsofstiffeners. Typicaldamageprocessesofthereinforcedstructureswereanalyzed. Thehorizontalandverticalcracklengthsofcrevassewerecomparedaswellascrevassearea.The effectsofthestrengthanddistancefactorswerefoundonthereinforcedstructuressubjectedtounderwatercontactexplosion. Theresultsshowthatitcanbeeffectivetorestraincrevasseareawhenthe strengthfactorrisesintheverticaldirectionanditisnotsignificantwhenthestrengthfactorrisesin thehorizontaldirection.Thedistancefactorisindirectproportiontocrevasseareaandthecrevasse shapesarerelatedtobothofthetwofactorsdefined.
LS-DYNAwasusedtosimulatetheresponsesofdifferentreinforcedstructuressubjectedto underwatercontactexplosionbyconsideringdifferentreinforcementstrengthsandlocations.Strength anddistancefactorsweredefinedtodescribethestrengthandlocationsofstiffeners,respectively.Six modelswereproposedwithdifferentstrengthsofstiffenersandthreemodelsweredevelopedwithdifferentlocationsofstiffeners. Typicaldamageprocessesofthereinforcedstructureswereanalyzed. Thehorizontalandverticalcracklengthsofcrevassewerecomparedaswellascrevassearea.The effectsofthestrengthanddistancefactorswerefoundonthereinforcedstructuressubjectedtounderwatercontactexplosion. Theresultsshowthatitcanbeeffectivetorestraincrevasseareawhenthe strengthfactorrisesintheverticaldirectionanditisnotsignificantwhenthestrengthfactorrisesin thehorizontaldirection.Thedistancefactorisindirectproportiontocrevasseareaandthecrevasse shapesarerelatedtobothofthetwofactorsdefined.
2012, 32(6): 604-608.
doi: 10.11883/1001-1455(2012)06-0604-05
Abstract:
Animproveddifferencemethodofcharacteristicsisdiscribed.Twogroupsofcharacteristic equationswithentropytermsarededucedaccordingtothebasicmechanicsequations,andtheparticle pathlineisaddedintheequationsetasthethirdcharacteristicequation.Theisentropicflowafter blastshockwavecanbesolvedusingthethreecharacteristicequations.Thereisnoartificialviscosity termintheequations,sotheinfluenceofthehumaninterventionisreduced.Then,byapplyingthe improveddifferencemethodofcharacteristics,theunderwaterexplosionofthesphericalchargeof compositionB-3isstimulated.Inthescaleddistanceof1R/R04,thepeakpressureerrorbetween thenumericalcalculationresultsandtheexperimentcurveislessthan13.1%,whichprovesthatthe improveddifferencemethodofcharacteristicsisreasonable.
Animproveddifferencemethodofcharacteristicsisdiscribed.Twogroupsofcharacteristic equationswithentropytermsarededucedaccordingtothebasicmechanicsequations,andtheparticle pathlineisaddedintheequationsetasthethirdcharacteristicequation.Theisentropicflowafter blastshockwavecanbesolvedusingthethreecharacteristicequations.Thereisnoartificialviscosity termintheequations,sotheinfluenceofthehumaninterventionisreduced.Then,byapplyingthe improveddifferencemethodofcharacteristics,theunderwaterexplosionofthesphericalchargeof compositionB-3isstimulated.Inthescaleddistanceof1R/R04,thepeakpressureerrorbetween thenumericalcalculationresultsandtheexperimentcurveislessthan13.1%,whichprovesthatthe improveddifferencemethodofcharacteristicsisreasonable.
2012, 32(6): 609-615.
doi: 10.11883/1001-1455(2012)06-0609-07
Abstract:
Thefiniteelementsoftware,ABAQUS/Explicit,wasusedtonumericallyanalyzetheplasticdamageevolutionofatypicalconcretegravitydamsmonolithbyconsideringthefluid- structure couplingbetweenthedamandthewateraswellasthetensionandcompressiondamageintheconcrete. Thewaterwassimulatedbyusinganacousticelement.Theresultsshowthatthereexistthree potentialfailuremodesinthedam.Besidesthefailureneartheexplosionlocation,anoversizedamage rangeofthedambasemaycausethedamslideoreventilttowardsthedownstream.Thetilttowards thedownstreamoftheabutment,whichiscausedbylocalfailureorfracture,mayleadtoadecrease ofthedamswaterretainingheightandovertopping.Andthelocalrein
Thefiniteelementsoftware,ABAQUS/Explicit,wasusedtonumericallyanalyzetheplasticdamageevolutionofatypicalconcretegravitydamsmonolithbyconsideringthefluid- structure couplingbetweenthedamandthewateraswellasthetensionandcompressiondamageintheconcrete. Thewaterwassimulatedbyusinganacousticelement.Theresultsshowthatthereexistthree potentialfailuremodesinthedam.Besidesthefailureneartheexplosionlocation,anoversizedamage rangeofthedambasemaycausethedamslideoreventilttowardsthedownstream.Thetilttowards thedownstreamoftheabutment,whichiscausedbylocalfailureorfracture,mayleadtoadecrease ofthedamswaterretainingheightandovertopping.Andthelocalrein
2012, 32(6): 616-622.
doi: 10.11883/1001-1455(2012)06-0616-07
Abstract:
Toresearchthemotionofabulletintothemusculartissue,thegelatinwasusedtosimulate themusculartissue.Basedonthepropertiesofthegelatin,atwo-dimensionalmotionmodelwasestablishedfortheprojectilepenetratingthegelatininwhichreflectingthedifferencebetweenattackangleandy wangle.Andthebulletmotionsinthehorizontalandverticaldirectionsweretakenintoaccountintheestablishedmotionmodel. BasedontheRunge-Kuttamethod,themotionmodelwascalculatedbychoosingtheordinarybulletswiththediametersof7.62and5.80mm, respectively,askillerelements. Thecalculatedresultswerecompared withthecorrespondingexperimentalresults. Comparisonsshowthatthetwo-dimensionalmotionmodelcandescribethemotionofthebulletspenetratingthegelatinaccurately. Andthemotionmodelestablishedisofacertaincommonalityandcan provideatheoreticalreferencefortheammunitiondesignandthewoundtreatment.
Toresearchthemotionofabulletintothemusculartissue,thegelatinwasusedtosimulate themusculartissue.Basedonthepropertiesofthegelatin,atwo-dimensionalmotionmodelwasestablishedfortheprojectilepenetratingthegelatininwhichreflectingthedifferencebetweenattackangleandy wangle.Andthebulletmotionsinthehorizontalandverticaldirectionsweretakenintoaccountintheestablishedmotionmodel. BasedontheRunge-Kuttamethod,themotionmodelwascalculatedbychoosingtheordinarybulletswiththediametersof7.62and5.80mm, respectively,askillerelements. Thecalculatedresultswerecompared withthecorrespondingexperimentalresults. Comparisonsshowthatthetwo-dimensionalmotionmodelcandescribethemotionofthebulletspenetratingthegelatinaccurately. Andthemotionmodelestablishedisofacertaincommonalityandcan provideatheoreticalreferencefortheammunitiondesignandthewoundtreatment.
2012, 32(6): 623-628.
doi: 10.11883/1001-1455(2012)06-0623-06
Abstract:
Aseriesofexperimentswerecarriedouttoexploretheeffectsofpackagematerialsonthe performancesofapiezoresistive MEMSaccelerometerunderhigh-gimpact.Fortheaccelerometers packagedwithceramicandstainlesssteel,respectively,theresidualstressandthepiezoresistancevariationweremeasuredbyusingaRamanspectrometerbeforeandafterpackage. Theirsensitivityand anti-overloadcapabilityweretestedbyapplyingaMachethammerandaHopkinsonbar,respectively. Andthetestprecisiondifferencesbetweenthetwoaccelerometerswereanalyzedinthefieldexperiment. Theexperimentalresultsshowthattheresidualstressincrementsoftheaccelerometerswith stainlesssteelpackagearehigherthanthoseoftheaccelerometerswithceramicpackageandthepiezoresistancevariationscausedbytheresidual tressesarehigher.Buttheaccelerometerswithstainlesssteelpackagehavehighersensitivitiesandbetteranti- overloadcapabilitiescomparedwiththeaccelerometerswithceramicpackage.
Aseriesofexperimentswerecarriedouttoexploretheeffectsofpackagematerialsonthe performancesofapiezoresistive MEMSaccelerometerunderhigh-gimpact.Fortheaccelerometers packagedwithceramicandstainlesssteel,respectively,theresidualstressandthepiezoresistancevariationweremeasuredbyusingaRamanspectrometerbeforeandafterpackage. Theirsensitivityand anti-overloadcapabilityweretestedbyapplyingaMachethammerandaHopkinsonbar,respectively. Andthetestprecisiondifferencesbetweenthetwoaccelerometerswereanalyzedinthefieldexperiment. Theexperimentalresultsshowthattheresidualstressincrementsoftheaccelerometerswith stainlesssteelpackagearehigherthanthoseoftheaccelerometerswithceramicpackageandthepiezoresistancevariationscausedbytheresidual tressesarehigher.Buttheaccelerometerswithstainlesssteelpackagehavehighersensitivitiesandbetteranti- overloadcapabilitiescomparedwiththeaccelerometerswithceramicpackage.
2012, 32(6): 629-634.
doi: 10.11883/1001-1455(2012)06-0629-06
Abstract:
ByusingasplitHopkinsonpressurebarsystem,thedamageeffectsofporoussandstone specimenswereexperimentallyinvestigatedbyconsideringfluid-solidcoupling.Thedynamicstressstraincurvesoftheporoussandstonespecimenswereobtainedundertherepeatedimpactloadings withdifferentspeedsandtheiracousticwavespeedsweremeasuredbeforeandafterimpact.Thedamageresultsofthesandstonespecimenswereanalyzedandthemaininfluencingfactorswereexplored. Thevaryingcurvesofthebreakingstrengthsofthesandstonewereobtained withacousticwave speedsandporousratio,respectively.Andtheinfluencesofporosityandcouplingmediawereproposedontheimpactdamageeffectsofporoussandstone.
ByusingasplitHopkinsonpressurebarsystem,thedamageeffectsofporoussandstone specimenswereexperimentallyinvestigatedbyconsideringfluid-solidcoupling.Thedynamicstressstraincurvesoftheporoussandstonespecimenswereobtainedundertherepeatedimpactloadings withdifferentspeedsandtheiracousticwavespeedsweremeasuredbeforeandafterimpact.Thedamageresultsofthesandstonespecimenswereanalyzedandthemaininfluencingfactorswereexplored. Thevaryingcurvesofthebreakingstrengthsofthesandstonewereobtained withacousticwave speedsandporousratio,respectively.Andtheinfluencesofporosityandcouplingmediawereproposedontheimpactdamageeffectsofporoussandstone.
2012, 32(6): 635-640.
doi: 10.11883/1001-1455(2012)06-0635-06
Abstract:
Toanalyzethesteadynon-idealdetonationwith metalconfinement,theJWLequationof stateisadoptedfortheunreactedexplosiveanddetonationproduct,andthep(,T)equationofstate forthemetal.Andthethree-termLee-Tarverreactionrateisadoptedinthechemicalreactionmodel. Basedonthehypothesisthatthedeflectangleoftheflowcrossingtheleadingshockwaveislinear withheight,theshapeoftheleadingshockwavecanbeobtainedfromthepolarcurve,anddetonation edgeanglemaybeobtainedfromthemarchingpointbetweenthepolarcurvesoftheunreactedexplosiveandthemetal. Basedonthehypothesisthatthestreamlinesbehindtheleadingshockwaveare straightanddiverging,thegoverningequationsofdetonationwillchangefromthepartialdifferential typeintotheordinarydifferentialtype,thenthelocationsofthesoniclineandtheendofchemistry reactioncanbeobtainedthroughsolvingtheordinarydifferentiaequationsalongthestreamlines.The polarcurvesoftheshockedmetalshowthattheflowsbehindtherefractionshockmaybesupersonic withthehardcompressibility,orsubsonicwiththeeasycompressibility.Thetheoryresultsaboutthe structurecharacterofthedetonationreactionzoneandtheflowstateinsidetheconfinementmetalagreeswiththehighprecisionnumericalsimula ion
Toanalyzethesteadynon-idealdetonationwith metalconfinement,theJWLequationof stateisadoptedfortheunreactedexplosiveanddetonationproduct,andthep(,T)equationofstate forthemetal.Andthethree-termLee-Tarverreactionrateisadoptedinthechemicalreactionmodel. Basedonthehypothesisthatthedeflectangleoftheflowcrossingtheleadingshockwaveislinear withheight,theshapeoftheleadingshockwavecanbeobtainedfromthepolarcurve,anddetonation edgeanglemaybeobtainedfromthemarchingpointbetweenthepolarcurvesoftheunreactedexplosiveandthemetal. Basedonthehypothesisthatthestreamlinesbehindtheleadingshockwaveare straightanddiverging,thegoverningequationsofdetonationwillchangefromthepartialdifferential typeintotheordinarydifferentialtype,thenthelocationsofthesoniclineandtheendofchemistry reactioncanbeobtainedthroughsolvingtheordinarydifferentiaequationsalongthestreamlines.The polarcurvesoftheshockedmetalshowthattheflowsbehindtherefractionshockmaybesupersonic withthehardcompressibility,orsubsonicwiththeeasycompressibility.Thetheoryresultsaboutthe structurecharacterofthedetonationreactionzoneandtheflowstateinsidetheconfinementmetalagreeswiththehighprecisionnumericalsimula ion
2012, 32(6): 641-646.
doi: 10.11883/1001-1455(2012)06-0641-06
Abstract:
Alargeframecontinuousrotatingmirrorframingcamerawasdevelopedbasedoncoaxial imagingtheoryandcontrollingdefocusingrangetomeettheneedsofstudyonadvancedweapon.It hasframesize30mm18mm,dynamicvisualresolution35mm-1,numberofframes80,framing ratefrom1104to5105s-1.Byuseofafibersensorsystemwhichproducetherotationsignaland transferittocontrolsystem,thedisturbancefrom highspeedrotating mirrorisaverted,andthe measurementveracityofrotatingspeedisensured.Thecamerarunsconvenientlyundernewcontrol system,andattainstheperfectresultsinthedetonationandshockwavephysicsexperimentstudy.
Alargeframecontinuousrotatingmirrorframingcamerawasdevelopedbasedoncoaxial imagingtheoryandcontrollingdefocusingrangetomeettheneedsofstudyonadvancedweapon.It hasframesize30mm18mm,dynamicvisualresolution35mm-1,numberofframes80,framing ratefrom1104to5105s-1.Byuseofafibersensorsystemwhichproducetherotationsignaland transferittocontrolsystem,thedisturbancefrom highspeedrotating mirrorisaverted,andthe measurementveracityofrotatingspeedisensured.Thecamerarunsconvenientlyundernewcontrol system,andattainstheperfectresultsinthedetonationandshockwavephysicsexperimentstudy.
2012, 32(6): 647-652.
doi: 10.11883/1001-1455(2012)06-0647-06
Abstract:
Aseriesofblastexperimentswithandwithoutvibration-isolatingtrencheswereimplementedintheblastcontainmentchamberwithanellipticconewhichhavinganinsidediameterof2mand awallthicknessof0.4m.Andtheverticalandhorizontalgroundvibrationvelocitiesat6different pointsonthesurroundinggroundofthechamberweremeasured.Theexperimentalresultsshowthat thegroundvibrationdurationislessthan0.2seconds,thefrequencyspectraoftheverticalandhorizontalvibrationsareinthe20- 500Hzand200-800Hzranges,respectively.Thehorizontalvelocity amplitudesafterattenuationbythetrenchesareone-tenthofthosebeforeattenuation,aswellasonefourthtoone- thirdfortheverticalvelocityamplitudes.Butthetrencheshavenoobviouseffectonthe frequencyspectraofthegroundvibrationwaves.Thevibration-isolatingtrencheswith1mdepthhave noattenuationeffectontheblastseismicwaves,buttheattenuationeffectwillberemarkablewhen thedepthsofthetrenchesare1.5-2.0timesaslongasthewavelengthsoftheRayleighwaves.
Aseriesofblastexperimentswithandwithoutvibration-isolatingtrencheswereimplementedintheblastcontainmentchamberwithanellipticconewhichhavinganinsidediameterof2mand awallthicknessof0.4m.Andtheverticalandhorizontalgroundvibrationvelocitiesat6different pointsonthesurroundinggroundofthechamberweremeasured.Theexperimentalresultsshowthat thegroundvibrationdurationislessthan0.2seconds,thefrequencyspectraoftheverticalandhorizontalvibrationsareinthe20- 500Hzand200-800Hzranges,respectively.Thehorizontalvelocity amplitudesafterattenuationbythetrenchesareone-tenthofthosebeforeattenuation,aswellasonefourthtoone- thirdfortheverticalvelocityamplitudes.Butthetrencheshavenoobviouseffectonthe frequencyspectraofthegroundvibrationwaves.Thevibration-isolatingtrencheswith1mdepthhave noattenuationeffectontheblastseismicwaves,buttheattenuationeffectwillberemarkablewhen thedepthsofthetrenchesare1.5-2.0timesaslongasthewavelengthsoftheRayleighwaves.
2012, 32(6): 653-657.
doi: 10.11883/1001-1455(2012)06-0653-05
Abstract:
Simulationswereperformedtoanalyzethepropagationandsuperpositionprocessesofstress wavesaimingtothreedifferentchargestructuresundertop,bottomandsimultaneousinitiations,respectively. Thepressureinthemiddleoftheboreholeincreasesgreatlywhenincreasingthetopcharge undertopandsimultaneousinitiations.Adoptingbottominitiation,thepressurepeaksofstemming partarehigherthanthoseadoptingtheothertwoinitiations.Forthreechargestructuresunderbottominitiation, comparisonsofthepressurecurvesalongtheboreholesdisplaythatmoreeven-distributedpressurecanbeobtainedandthecorrespondingmeanpressureishigherbyincreasingthetop charge.Thesimulatedresultswereappliedtothefieldpracticeandthebigfragmentsweredeletedbasically. Sotheganguebackfillefficiencycanincreasebyadoptingair-deckchargeblasting.
Simulationswereperformedtoanalyzethepropagationandsuperpositionprocessesofstress wavesaimingtothreedifferentchargestructuresundertop,bottomandsimultaneousinitiations,respectively. Thepressureinthemiddleoftheboreholeincreasesgreatlywhenincreasingthetopcharge undertopandsimultaneousinitiations.Adoptingbottominitiation,thepressurepeaksofstemming partarehigherthanthoseadoptingtheothertwoinitiations.Forthreechargestructuresunderbottominitiation, comparisonsofthepressurecurvesalongtheboreholesdisplaythatmoreeven-distributedpressurecanbeobtainedandthecorrespondingmeanpressureishigherbyincreasingthetop charge.Thesimulatedresultswereappliedtothefieldpracticeandthebigfragmentsweredeletedbasically. Sotheganguebackfillefficiencycanincreasebyadoptingair-deckchargeblasting.
2012, 32(6): 658-662.
doi: 10.11883/1001-1455(2012)06-0658-05
Abstract:
BasedonthenumericalanalysiswithLS-DYNA,thedeformationanddamageofthereinforcedmasonrywallswereinvestigatedbyconsideringthefollowingfactors: wall-borneconstraint, masonrymaterialstrengthgrade,verticalreinforcementratio,height-to-spanratio,loadpeak,distancefromexplosivecentertowall, aholeinthewallandGFRPonthewall.Andthedistance-time curvesofthewallswereobtainedaswellasthestress-timecurvesofthemasonrymaterialsandsteel bars.Meanwhile,theanti-explosionperformancesofthereinforcedmasonrywallswerecomparedin thedifferentcasesandtheimportantfactorsinfluencingthestructureresponseweredetermined.Itis helpfulfortheanti-explosiondesignaboutthereinforcedmasonrystructure.
BasedonthenumericalanalysiswithLS-DYNA,thedeformationanddamageofthereinforcedmasonrywallswereinvestigatedbyconsideringthefollowingfactors: wall-borneconstraint, masonrymaterialstrengthgrade,verticalreinforcementratio,height-to-spanratio,loadpeak,distancefromexplosivecentertowall, aholeinthewallandGFRPonthewall.Andthedistance-time curvesofthewallswereobtainedaswellasthestress-timecurvesofthemasonrymaterialsandsteel bars.Meanwhile,theanti-explosionperformancesofthereinforcedmasonrywallswerecomparedin thedifferentcasesandtheimportantfactorsinfluencingthestructureresponseweredetermined.Itis helpfulfortheanti-explosiondesignaboutthereinforcedmasonrystructure.
2012, 32(6): 663-668.
doi: 10.11883/1001-1455(2012)06-0663-06
Abstract:
TheexplosionprocessesofsphericalPETNchargesinLantiangranitewerenumericallysimulatedbyusingthesoftwareAUTODYN. ParticlevelocityanddisplacementcurvesatdifferentlocationsinLantiangranitewereobtainedandtheinfluencesofexplosivepropertiesonro kparticlemovementwerequalitativelyanalyzed. Thesimulatedparticlevelocityanddisplacementareconsistentwith theexistentexperimentalresults.Thereliesalargedistinctionbetweenparticlevelocitypeaksfrom simulationandexperiment,buttheerrorofparticledisplacementpeakislessthantwentypercent,of whichinfluencedbyvelocitypeak,pulseduration,risetimeandvelocityattenuation.Inthecaseof thesameexplosionenergy,therockparticlevelocitypeaksinducedbytheexplosionoftheHMX, PETN,andTNTchargesinLantiangranitedecreaseinturn.ButtheparticledisplacementpeakinducedbytheexplosionoftheTNTchargeisthebiggest, theparticledisplacementpeakinducedby theexplosionofthePETNchargeistheleast.Thereactionrateofnon-idealexplosivehasanobvious effectontheparticlevelocityanddisplacementpeakswhichincreasewiththeincreasingofthereaction rate.
TheexplosionprocessesofsphericalPETNchargesinLantiangranitewerenumericallysimulatedbyusingthesoftwareAUTODYN. ParticlevelocityanddisplacementcurvesatdifferentlocationsinLantiangranitewereobtainedandtheinfluencesofexplosivepropertiesonro kparticlemovementwerequalitativelyanalyzed. Thesimulatedparticlevelocityanddisplacementareconsistentwith theexistentexperimentalresults.Thereliesalargedistinctionbetweenparticlevelocitypeaksfrom simulationandexperiment,buttheerrorofparticledisplacementpeakislessthantwentypercent,of whichinfluencedbyvelocitypeak,pulseduration,risetimeandvelocityattenuation.Inthecaseof thesameexplosionenergy,therockparticlevelocitypeaksinducedbytheexplosionoftheHMX, PETN,andTNTchargesinLantiangranitedecreaseinturn.ButtheparticledisplacementpeakinducedbytheexplosionoftheTNTchargeisthebiggest, theparticledisplacementpeakinducedby theexplosionofthePETNchargeistheleast.Thereactionrateofnon-idealexplosivehasanobvious effectontheparticlevelocityanddisplacementpeakswhichincreasewiththeincreasingofthereaction rate.
2012, 32(6): 669-672.
doi: 10.11883/1001-1455(2012)06-0669-04
Abstract:
Thealuminumpowderof2mparticlesizewastakenasthemediumandaseriesofdustexplosionreliefexperimentswerecarriedoutbylinkingthesteel eliefpipeswith25mminternaldiametertothetopofthecylindricalsteelvesselwith68mminternaldiameterand305mmheight. The steelreliefpipelengthandthedustmassconcentrationwereadjusted,respectively,toinvestigatethe pressurecharacteristicsinthevesselandthereliefpipeandtoexploreprincipallythesecondaryexplosion- inducedconditionintheexplosionreliefprocess.Experimentalresultsdemonstratethatsecondaryexplosionmayoccurwhenthereliefpipelengthanddustmassconcentrationarenolessthan1500 mmand500g/m3,respectively.Thepressurewavesinducedbysecondaryexplosionpropagatetowardboththevesselandthereliefpipeend. Thepressurewavespropagatingtowardthevesseldisturbthereliefprocessandinducetheresidualunburntcombustible mixtureinthevesselreact. Hence,secondarypressurepeakappearsinthevessel.
Thealuminumpowderof2mparticlesizewastakenasthemediumandaseriesofdustexplosionreliefexperimentswerecarriedoutbylinkingthesteel eliefpipeswith25mminternaldiametertothetopofthecylindricalsteelvesselwith68mminternaldiameterand305mmheight. The steelreliefpipelengthandthedustmassconcentrationwereadjusted,respectively,toinvestigatethe pressurecharacteristicsinthevesselandthereliefpipeandtoexploreprincipallythesecondaryexplosion- inducedconditionintheexplosionreliefprocess.Experimentalresultsdemonstratethatsecondaryexplosionmayoccurwhenthereliefpipelengthanddustmassconcentrationarenolessthan1500 mmand500g/m3,respectively.Thepressurewavesinducedbysecondaryexplosionpropagatetowardboththevesselandthereliefpipeend. Thepressurewavespropagatingtowardthevesseldisturbthereliefprocessandinducetheresidualunburntcombustible mixtureinthevesselreact. Hence,secondarypressurepeakappearsinthevessel.
