2014 Vol. 34, No. 1
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2014, 34(1): 1-5.
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Abstract:
To investigate the dynamic strength behaviors of a Zr-based bulk metallic glass(BMG), Zr51Ti5Ni10Cu25Al9(in atomic percent), a series of reverse-impact experiments were performed in the peak shock stress range from 37to 66GPa.A displacement interferometer system for any reflector(DISAR)was used to measure the particle velocity profiles at the sample/LiF window interface.By analyzing the measured particle velocity profiles, the yield strength and shear modulus of the Zr-based BMG were obtained.The experimental results show that both the yield strength and the shear modulus of the Zr-based BMG increase with the increasing of the shock stresses in the stress range considered here.And the shear stress relaxation across the shock wave front of the Zr-based BMG is not due to the shock-induced damage/failure or temperature softening.
To investigate the dynamic strength behaviors of a Zr-based bulk metallic glass(BMG), Zr51Ti5Ni10Cu25Al9(in atomic percent), a series of reverse-impact experiments were performed in the peak shock stress range from 37to 66GPa.A displacement interferometer system for any reflector(DISAR)was used to measure the particle velocity profiles at the sample/LiF window interface.By analyzing the measured particle velocity profiles, the yield strength and shear modulus of the Zr-based BMG were obtained.The experimental results show that both the yield strength and the shear modulus of the Zr-based BMG increase with the increasing of the shock stresses in the stress range considered here.And the shear stress relaxation across the shock wave front of the Zr-based BMG is not due to the shock-induced damage/failure or temperature softening.
2014, 34(1): 6-10.
Abstract:
The explosive compaction-coating technology was introduced in detail and was used to prepare the large-area copper coating.And the surface morphology, element content and thickness of the prepared copper coating were investigated by means of optical microscope, scanning electron microscopy and energy dispersion spectrum.The porosity of the copper coating was measured by the quantitative line method in its SEM photograph.The hardness of the copper coating was observed by a microhardness tester.The thickness of the copper coating was 280μm, the porosity was about 2%, the average microhardness was about 114HV0.05, and the element content remained roughly constant before and after the experiment.The results show that the prepared copper coating has excellent uniformity and compactness and no oxidation of the copper powder can occur during the process of the copper coating formation.
The explosive compaction-coating technology was introduced in detail and was used to prepare the large-area copper coating.And the surface morphology, element content and thickness of the prepared copper coating were investigated by means of optical microscope, scanning electron microscopy and energy dispersion spectrum.The porosity of the copper coating was measured by the quantitative line method in its SEM photograph.The hardness of the copper coating was observed by a microhardness tester.The thickness of the copper coating was 280μm, the porosity was about 2%, the average microhardness was about 114HV0.05, and the element content remained roughly constant before and after the experiment.The results show that the prepared copper coating has excellent uniformity and compactness and no oxidation of the copper powder can occur during the process of the copper coating formation.
2014, 34(1): 11-16.
Abstract:
2014, 34(1): 17-22.
doi: 10.11883/1001-1455(2014)01-0017-06
Abstract:
According to the time effect of particle dispersion and sedimentation during the dust cloud formation, the paper points out that the internationally accepted method that only by the gas phase turbulence degrees or single dust concentration to set the fixed ignition delay time, is of uncertainty.To investigate the effects of the ignition delay time on the dust explosion pressure and the pressure rise rate, a series of explosion experiments were carried out in a 5－L cylindrical vessel filled with aluminum dust.The results show that the ignition delay time has a significant effect on the measured values of the explosion pressure and the pressure rise rate and there exists an optimum ignition delay time to maximize the explosion pressure.With the increasing of the dust concentration, the optimum ignition delay time increases gradually to the maximum and then remains unchanged.The maximum explosion pressure and the maximum pressure rise rate under the optimum ignition delay time are obviously higher than those under the fixed ignition delay time of 60ms.If the fixed ignition delay time of 60ms is used for all the aluminum dust with different concentrations, the measured maximum explosion pressure and the maximum pressure rise rate may largely deviate from the actual values.
According to the time effect of particle dispersion and sedimentation during the dust cloud formation, the paper points out that the internationally accepted method that only by the gas phase turbulence degrees or single dust concentration to set the fixed ignition delay time, is of uncertainty.To investigate the effects of the ignition delay time on the dust explosion pressure and the pressure rise rate, a series of explosion experiments were carried out in a 5－L cylindrical vessel filled with aluminum dust.The results show that the ignition delay time has a significant effect on the measured values of the explosion pressure and the pressure rise rate and there exists an optimum ignition delay time to maximize the explosion pressure.With the increasing of the dust concentration, the optimum ignition delay time increases gradually to the maximum and then remains unchanged.The maximum explosion pressure and the maximum pressure rise rate under the optimum ignition delay time are obviously higher than those under the fixed ignition delay time of 60ms.If the fixed ignition delay time of 60ms is used for all the aluminum dust with different concentrations, the measured maximum explosion pressure and the maximum pressure rise rate may largely deviate from the actual values.
2014, 34(1): 23-27.
doi: 10.11883/1001-1455(2014)01-0023-05
Abstract:
To investigate the effects of the laneway surfaces on the methane explosion, the mechanism of the methane explosion was analyzed and a physical model for the laneway was proposed.Based on the above, numerical simulations were conducted to explore the effects of the inner surface roughness on the explosion propagation by modifying the drag coefficient and the turbulent length scale in the reaction model of the methane explosion.The simulated results display that the laneway surface can influence evidently the methane explosion in it.The higher the values of the drag coefficient and the turbulent length scale, the higher the peak overpressure of the methane explosion.And the simulated results correspond best to the experimental data when the drag coefficient and the turbulent length scale are 3 and 0.008, respectively.
To investigate the effects of the laneway surfaces on the methane explosion, the mechanism of the methane explosion was analyzed and a physical model for the laneway was proposed.Based on the above, numerical simulations were conducted to explore the effects of the inner surface roughness on the explosion propagation by modifying the drag coefficient and the turbulent length scale in the reaction model of the methane explosion.The simulated results display that the laneway surface can influence evidently the methane explosion in it.The higher the values of the drag coefficient and the turbulent length scale, the higher the peak overpressure of the methane explosion.And the simulated results correspond best to the experimental data when the drag coefficient and the turbulent length scale are 3 and 0.008, respectively.
2014, 34(1): 28-34.
doi: 10.11883/1001-1455(2014)01-0028-07
Abstract:
The fly-ash cenospheres-reinforced 1199Al-matrix composite foam was prepared by the pressure infiltration technique, in which containing the 80-μm-sized fly-ash cenospheres with the volume fraction of 0.4.Dynamic compression experiments were performed with a split Hopkinson pressure bar(SHPB)setup to investigate the dynamic compression properties and energy-absorption capability of the prepared composite foam in the strain rate range from 1 700s-1 to 2 900s-1.And the fractured surfaces of the compressed specimens were observed by a scanning electron microscopy.Moreover, the energy-absorption capability and the deformation mechanism of the prepared composite faom in dynamic compressions were compared with those of it in quasi-static compressions by an Instron 5569 tensile machine.The results show that the cenospheres-reinforced 1199Al-matrix composite foam is a strain-rate sensitive material.Its flow stress and plastic strain at the high strain rates are obviously higher than those under the quasi-static conditions.And the strain-rate hardening effect can more markedly influence the flow stress of the cenospheres-reinforced 1199Al-matrix composite foam than the strain-hardening effect.Furthermore, there are some differences between the quasi-static and dynamic compressive deformation mechanisms in the cenospheres-reinforced 1199Al-matrix composite foam.Under dynamic loadings, the fly-ash cenospheres in the cenospheres-reinforced 1199Al-matrix composite foam can be simultaneously compressed when the Al-matrix material is being filled, and there lies a good coordinate deformation capacity between the components.
The fly-ash cenospheres-reinforced 1199Al-matrix composite foam was prepared by the pressure infiltration technique, in which containing the 80-μm-sized fly-ash cenospheres with the volume fraction of 0.4.Dynamic compression experiments were performed with a split Hopkinson pressure bar(SHPB)setup to investigate the dynamic compression properties and energy-absorption capability of the prepared composite foam in the strain rate range from 1 700s-1 to 2 900s-1.And the fractured surfaces of the compressed specimens were observed by a scanning electron microscopy.Moreover, the energy-absorption capability and the deformation mechanism of the prepared composite faom in dynamic compressions were compared with those of it in quasi-static compressions by an Instron 5569 tensile machine.The results show that the cenospheres-reinforced 1199Al-matrix composite foam is a strain-rate sensitive material.Its flow stress and plastic strain at the high strain rates are obviously higher than those under the quasi-static conditions.And the strain-rate hardening effect can more markedly influence the flow stress of the cenospheres-reinforced 1199Al-matrix composite foam than the strain-hardening effect.Furthermore, there are some differences between the quasi-static and dynamic compressive deformation mechanisms in the cenospheres-reinforced 1199Al-matrix composite foam.Under dynamic loadings, the fly-ash cenospheres in the cenospheres-reinforced 1199Al-matrix composite foam can be simultaneously compressed when the Al-matrix material is being filled, and there lies a good coordinate deformation capacity between the components.
2014, 34(1): 35-40.
doi: 10.11883/1001-1455(2014)01-0035-06
Abstract:
The typical copper liner with a small cone angle was divided into four sections along the bus direction via the explicit finite software LS-DYNA, and the tracer point method was used to study the movement of the liner element and the structure modules of the effective metallic jet.The result indicates that the liner material may be divided into six sections by velocity interval after the jet formation and stabilization.The highest-velocity section is made of the top material inside the liner, and the mid-higher velocity section and the mid-velocity section made of the middle and lower half material inside the liner, respectively.In the height range of about 0.25times as high as the liner height away from the liner bottom, the liner material can not become effective jets.And the initial material elements of the liner are distributed as tubular in the effective jet.
The typical copper liner with a small cone angle was divided into four sections along the bus direction via the explicit finite software LS-DYNA, and the tracer point method was used to study the movement of the liner element and the structure modules of the effective metallic jet.The result indicates that the liner material may be divided into six sections by velocity interval after the jet formation and stabilization.The highest-velocity section is made of the top material inside the liner, and the mid-higher velocity section and the mid-velocity section made of the middle and lower half material inside the liner, respectively.In the height range of about 0.25times as high as the liner height away from the liner bottom, the liner material can not become effective jets.And the initial material elements of the liner are distributed as tubular in the effective jet.
2014, 34(1): 41-46.
doi: 10.11883/1001-1455(2014)01-0041-06
Abstract:
The in-plane dynamic behaviors of metal honeycombs filled by cells with various configurations and arrangements are studied by the finite element method using ANSYS/LS-DYNA.The deformation modes, crushing strength and energy-absorption ability are compared among these honeycombs while controlling their relative density and the impact velocity as uniform.It is shown that different cell configurations result in different stress states within the cell walls during the cells'collapse process, which thus influence the macroscopic mechanical properties of the honeycombs.According to the cell-walls'stress state, the involved honeycombs are divided into tow groups:membrane-dominated honeycombs and bending-dominated honeycombs.The results show that most of the absorbed energy of the honeycomb is transferred into the internal energy needed by the deformation.The percentage of the internal energy to the total absorbed energy is much more for the membrane-dominated honeycombs.The buckling of the cell-walls results in obvious oscillation in the stress-strain curves of the membrane-dominated honeycombs.The cell-walls in the membrane-dominated honeycombs will dissipate more internal energy during deformation, resulting in higher crushing strength and higher energy absorption ability than those of the bending-dominated ones.
The in-plane dynamic behaviors of metal honeycombs filled by cells with various configurations and arrangements are studied by the finite element method using ANSYS/LS-DYNA.The deformation modes, crushing strength and energy-absorption ability are compared among these honeycombs while controlling their relative density and the impact velocity as uniform.It is shown that different cell configurations result in different stress states within the cell walls during the cells'collapse process, which thus influence the macroscopic mechanical properties of the honeycombs.According to the cell-walls'stress state, the involved honeycombs are divided into tow groups:membrane-dominated honeycombs and bending-dominated honeycombs.The results show that most of the absorbed energy of the honeycomb is transferred into the internal energy needed by the deformation.The percentage of the internal energy to the total absorbed energy is much more for the membrane-dominated honeycombs.The buckling of the cell-walls results in obvious oscillation in the stress-strain curves of the membrane-dominated honeycombs.The cell-walls in the membrane-dominated honeycombs will dissipate more internal energy during deformation, resulting in higher crushing strength and higher energy absorption ability than those of the bending-dominated ones.
2014, 34(1): 47-51.
doi: 10.11883/1001-1455(2014)01-0047-05
Abstract:
By using the precision shaped charge warheads with the caliber of 36mm, anti-penetration experiments were conducted on the explosive reactive armors(ERAs)encapsulated by three different material layers with the same equivalent thickness, respectively.And the encapsulation layers were made of alumina, silicon carbide and steel plates, respectively.The experimental results show that for this armor configuration, after passing the ERAs with alumina and silicon carbide plates, the penetration depths of the shaped-charge jets decrease 82%and 88%, respectively, which are comparable to those in the cases of steel plates.And the interactions of the jets with the ceramic and steel plates were simulated by applying the finite-element code LS-DYNA3D.The simulation results display that after interaction with the jets, the ceramic plates shatter and break into pieces from the edge to the center.And the interaction mechanism between the shaped-charge jet back and the steel plate is an intermittent disturbance, whereas it is a continuous disturbance with the ceramic plates.
By using the precision shaped charge warheads with the caliber of 36mm, anti-penetration experiments were conducted on the explosive reactive armors(ERAs)encapsulated by three different material layers with the same equivalent thickness, respectively.And the encapsulation layers were made of alumina, silicon carbide and steel plates, respectively.The experimental results show that for this armor configuration, after passing the ERAs with alumina and silicon carbide plates, the penetration depths of the shaped-charge jets decrease 82%and 88%, respectively, which are comparable to those in the cases of steel plates.And the interactions of the jets with the ceramic and steel plates were simulated by applying the finite-element code LS-DYNA3D.The simulation results display that after interaction with the jets, the ceramic plates shatter and break into pieces from the edge to the center.And the interaction mechanism between the shaped-charge jet back and the steel plate is an intermittent disturbance, whereas it is a continuous disturbance with the ceramic plates.
2014, 34(1): 52-58.
doi: 10.11883/1001-1455(2014)01-0052-07
Abstract:
The finite element program LS-DYNA3D and the molecular dynamic method were applied to investigate the plastic zone formation, evolution process and the consequent dynamic failure behaviors under the dynamic tensile loading in a metal sheet with a preset flaw at macroscopic and microscopic levels, respectively.The calculated results show that the formation of the plastic zone stems from the stress wave-flaw and stress wave-stress wave interactions.The macroscopic and microscopic simulations represent the similar physical characteristics:the crack initiates at the front of the flaw boundary, then connects with the flaw and eventually leads to the global failure.
The finite element program LS-DYNA3D and the molecular dynamic method were applied to investigate the plastic zone formation, evolution process and the consequent dynamic failure behaviors under the dynamic tensile loading in a metal sheet with a preset flaw at macroscopic and microscopic levels, respectively.The calculated results show that the formation of the plastic zone stems from the stress wave-flaw and stress wave-stress wave interactions.The macroscopic and microscopic simulations represent the similar physical characteristics:the crack initiates at the front of the flaw boundary, then connects with the flaw and eventually leads to the global failure.
2014, 34(1): 59-66.
doi: 10.11883/1001-1455(2014)01-0059-08
Abstract:
The field tests were conducted to investigate the failure mechanism of the masonry infill wall under blast loading.The blast loads and the displacements of the wall under shock waves were measured.And the failure modes of the wall were obtained as well as the ejection and distribution of the wall fragments.The experimental results indicate that the failure modes of the wall are dependent mainly on the amplitudes of the blast loads and the collapse of the wall is leaded by the failure of the cement linings.Based on the above tests, the separated numerical models were established by using LS－DYNA to simulate the dynamic response and the damage of the masonry infill wall under blast loading.And the spreads of the cracks in the wall under different blast loads were obtained and the charge weights corresponding to the different failure modes were confirmed.The numerical results agree quite well with the test data.The boundary conditions can obviously affect the failure modes of the wall.
The field tests were conducted to investigate the failure mechanism of the masonry infill wall under blast loading.The blast loads and the displacements of the wall under shock waves were measured.And the failure modes of the wall were obtained as well as the ejection and distribution of the wall fragments.The experimental results indicate that the failure modes of the wall are dependent mainly on the amplitudes of the blast loads and the collapse of the wall is leaded by the failure of the cement linings.Based on the above tests, the separated numerical models were established by using LS－DYNA to simulate the dynamic response and the damage of the masonry infill wall under blast loading.And the spreads of the cracks in the wall under different blast loads were obtained and the charge weights corresponding to the different failure modes were confirmed.The numerical results agree quite well with the test data.The boundary conditions can obviously affect the failure modes of the wall.
2014, 34(1): 67-74.
doi: 10.11883/1001-1455(2014)01-0067-08
Abstract:
The thermal decomposition of each component in the composite explosive was described by the multi-step chemical kinetics model.A multi-component grid unit calculation method was put forward to calculate the thermal decomposition reaction processes of the HMX and TATB based composite explosives under the cook-off conditions.And the cook-off tests were carried out to measure the temperatures and ignition times of the explosives and verify the accuracies of the calculations.The thermal reaction performances of the composite explosives were analyzed by changing the mass fraction of each component in them.The results show that the exothermic decomposition of the HMX predominates in the thermal decomposition process of the HMX/TATB composite explosive.Moreover, the ignition time and temperature of the composite explosives increase with the increasing of the TATB contents in the composite explosives.
The thermal decomposition of each component in the composite explosive was described by the multi-step chemical kinetics model.A multi-component grid unit calculation method was put forward to calculate the thermal decomposition reaction processes of the HMX and TATB based composite explosives under the cook-off conditions.And the cook-off tests were carried out to measure the temperatures and ignition times of the explosives and verify the accuracies of the calculations.The thermal reaction performances of the composite explosives were analyzed by changing the mass fraction of each component in them.The results show that the exothermic decomposition of the HMX predominates in the thermal decomposition process of the HMX/TATB composite explosive.Moreover, the ignition time and temperature of the composite explosives increase with the increasing of the TATB contents in the composite explosives.
2014, 34(1): 75-79.
doi: 10.11883/1001-1455(2014)01-0075-05
Abstract:
By making some assumptions, an analytical model was presented to analyze the compression process of the cylindrical metal tube subjected to an inward sliding detonation.And the corresponding numerical simulations were carried out to verify the analytical results.The analytical results agreed well with the numerical ones.So by fitting the analytical data, two expressions were obtained for the explosive thickness needed to close the tube and the tube closing time, respectively, in which involving different tube parameters such as tube inner diameter and wall thickness.
By making some assumptions, an analytical model was presented to analyze the compression process of the cylindrical metal tube subjected to an inward sliding detonation.And the corresponding numerical simulations were carried out to verify the analytical results.The analytical results agreed well with the numerical ones.So by fitting the analytical data, two expressions were obtained for the explosive thickness needed to close the tube and the tube closing time, respectively, in which involving different tube parameters such as tube inner diameter and wall thickness.
2014, 34(1): 80-86.
doi: 10.11883/1001-1455(2014)01-0080-07
Abstract:
Based on the nonlinear explicit dynamic finite element program LS-DYNA and the multi-material Euler algorithm, the shock wave propagations were numerically simulated for the two explosion resources of the TNT dynamite and the acetylene-air gaseous mixture in free air field, respectively.The overpressures of the shock waves and the propagation principles were compared between the two blast-loading methods.Based on the equivalent-explosion energy, a formula for calculating the nominal scale distance of gas explosion was obtained in terms of overpressure.The results show that the Euler method can be used to calculate the propagation process of two kinds of explosion sources and the numerical results agree well with the ones based on the empirical equations.With the increasing of the propagation distances, the overpressures decrease sharply and the overpressure relative error between the two load methods decreases gradually.When the shock wave overpressure was lower than 0.5MPa, the acetylene-air gaseous mixture can replace the chemical dynamite for generating blast shock waves by the large nuclear blast load generator.
Based on the nonlinear explicit dynamic finite element program LS-DYNA and the multi-material Euler algorithm, the shock wave propagations were numerically simulated for the two explosion resources of the TNT dynamite and the acetylene-air gaseous mixture in free air field, respectively.The overpressures of the shock waves and the propagation principles were compared between the two blast-loading methods.Based on the equivalent-explosion energy, a formula for calculating the nominal scale distance of gas explosion was obtained in terms of overpressure.The results show that the Euler method can be used to calculate the propagation process of two kinds of explosion sources and the numerical results agree well with the ones based on the empirical equations.With the increasing of the propagation distances, the overpressures decrease sharply and the overpressure relative error between the two load methods decreases gradually.When the shock wave overpressure was lower than 0.5MPa, the acetylene-air gaseous mixture can replace the chemical dynamite for generating blast shock waves by the large nuclear blast load generator.
2014, 34(1): 87-92.
Abstract:
Based on the nonlinear wave theory, a mathematical model was proposed by applying the adaptive meshing technique in the ABAQUS code.And in the proposed model, the linear us-up Hugoniot equation of state was used for liquid.By using the proposed model, nonlinear harmonic response simulations were performed to numerically obtain the eigenfrequencies and the modals of the liquid sloshing in the tank－liquid system subjected to horizontal excitations.And the numerical results were compared with the analytical solutions to illuminate the reliability and availability of the proposed method.Finally, the nonlinear sloshing response characteristics of a rectangular liquid storage container were analyzed under a variety of excitations.
Based on the nonlinear wave theory, a mathematical model was proposed by applying the adaptive meshing technique in the ABAQUS code.And in the proposed model, the linear us-up Hugoniot equation of state was used for liquid.By using the proposed model, nonlinear harmonic response simulations were performed to numerically obtain the eigenfrequencies and the modals of the liquid sloshing in the tank－liquid system subjected to horizontal excitations.And the numerical results were compared with the analytical solutions to illuminate the reliability and availability of the proposed method.Finally, the nonlinear sloshing response characteristics of a rectangular liquid storage container were analyzed under a variety of excitations.
2014, 34(1): 93-98.
Abstract:
A loosing coupling strategy was adopted to simulate the propellant of the solid rocket motor.Pressure field was computed by solving the 2-D time-dependent Euler equations within an arbitrary Lagrangian-Eulerian(ALE)framework and the cell-centered finite volume scheme.The time discontinuous Galerkin extended finite element method is implemented to simulate the dynamic response in solid phase under the shock waves.The stress intensity factor was also calculated in the solid field subjected to the impulse loading.The results show that the propagation process of the shock wave in the crack displays highly nonlinear characteristics of reflection and diffraction.Both the displacement field and the stress intensity factor show oscillation effects under the coupled fluid-structure interaction.
A loosing coupling strategy was adopted to simulate the propellant of the solid rocket motor.Pressure field was computed by solving the 2-D time-dependent Euler equations within an arbitrary Lagrangian-Eulerian(ALE)framework and the cell-centered finite volume scheme.The time discontinuous Galerkin extended finite element method is implemented to simulate the dynamic response in solid phase under the shock waves.The stress intensity factor was also calculated in the solid field subjected to the impulse loading.The results show that the propagation process of the shock wave in the crack displays highly nonlinear characteristics of reflection and diffraction.Both the displacement field and the stress intensity factor show oscillation effects under the coupled fluid-structure interaction.
2014, 34(1): 99-105.
doi: 10.11883/1001-1455(2014)01-0099-07
Abstract:
The continuous detonation velocity test, the shock wave sensitivity test and the critical initiation pressure testwere developed, respectively, with reference to the GJB772A-97 card gap test.Based on the above tests, the detonation establishment process in the expired single-base propellantwas investigated, and the critical gap thickness and the critical initiation pressure were obtained.In the continuous detonation velocity test, the building-up process of the reactive shock wave was observed at the PMMA gap thickness of 50 mm and itdeveloped into a normal detonation at the PMMA gap thickness of90mm.The critical gap thicknesswas 50-52 mm obtained from the shock wave sensitivity test.And the critical initiation pressure was1.35-1.49 GPa obtained from the critical initiation pressure test.According to the above tests, the numerical simulations were conducted to calibrate the parameters of the reactive rate equation in the ignition-and-growth model for the expired single-base propellant.
The continuous detonation velocity test, the shock wave sensitivity test and the critical initiation pressure testwere developed, respectively, with reference to the GJB772A-97 card gap test.Based on the above tests, the detonation establishment process in the expired single-base propellantwas investigated, and the critical gap thickness and the critical initiation pressure were obtained.In the continuous detonation velocity test, the building-up process of the reactive shock wave was observed at the PMMA gap thickness of 50 mm and itdeveloped into a normal detonation at the PMMA gap thickness of90mm.The critical gap thicknesswas 50-52 mm obtained from the shock wave sensitivity test.And the critical initiation pressure was1.35-1.49 GPa obtained from the critical initiation pressure test.According to the above tests, the numerical simulations were conducted to calibrate the parameters of the reactive rate equation in the ignition-and-growth model for the expired single-base propellant.
2014, 34(1): 106-110.
doi: 10.11883/1001-1455(2014)01-0106-05
Abstract:
The blasting agentwas prepared by choosing Ce(NO3)3·6H2O as themajor ingredient to synthesize nano-CeO2 powder by the detonation method.The as-synthesized productswere characterized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).Thereby, the influences of the initiation manners on the crystallization, particle size andmorphology of the as-synthesized productswere analyzed.The results indicate that CeO2spherical nano-particleswhose crystal structure belongs to cubic system can be synthesized by using the blasting agent in which Ce(NO3)3·6H2O acting as themajor ingredient.And it is an effectivemethod to decrease the particle size and improve the spherification of nano-CeO2 by increasing the detonation velocity of the blasting agent.
The blasting agentwas prepared by choosing Ce(NO3)3·6H2O as themajor ingredient to synthesize nano-CeO2 powder by the detonation method.The as-synthesized productswere characterized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).Thereby, the influences of the initiation manners on the crystallization, particle size andmorphology of the as-synthesized productswere analyzed.The results indicate that CeO2spherical nano-particleswhose crystal structure belongs to cubic system can be synthesized by using the blasting agent in which Ce(NO3)3·6H2O acting as themajor ingredient.And it is an effectivemethod to decrease the particle size and improve the spherification of nano-CeO2 by increasing the detonation velocity of the blasting agent.
2014, 34(1): 111-114.
doi: 10.11883/1001-1455(2014)01-0111-04
Abstract:
The self-destructive device in clustermunitions was theoretically abstracted to establish a security failure model for investigating its security and reliability and evaluating the corresponding design.Based on informationism, twomodels were proposed for the output parameters of the detonation informations with sequential control and time-window sequential control, respectively.And the security and reliability of the M85 submunition fuze were anzlyzed aswell as the XM1161 fuze and the M230SD fuze.The theoretical analyse shows that the security and reliability of the M230SD fuze is better than those of the XM1161 fuze and the M230SD fuze.It is in agreementwith the experimental results.
The self-destructive device in clustermunitions was theoretically abstracted to establish a security failure model for investigating its security and reliability and evaluating the corresponding design.Based on informationism, twomodels were proposed for the output parameters of the detonation informations with sequential control and time-window sequential control, respectively.And the security and reliability of the M85 submunition fuze were anzlyzed aswell as the XM1161 fuze and the M230SD fuze.The theoretical analyse shows that the security and reliability of the M230SD fuze is better than those of the XM1161 fuze and the M230SD fuze.It is in agreementwith the experimental results.
2014, 34(1): 115-119.
doi: 10.11883/1001-1455(2014)01-0115-05
Abstract:
An electric probe measurement technique was proposed to measure the deformation undergone by the ektexines of the cylindrical steel shells subjected to the detonation of spherical explosive charges inside them.Numerical simulation was carried out to forecast the deformation of the steel shell ektexine at the section of the explosion center in the case of the spherical high-explosive charge equivalent to 120g TNT as well as 180g TNT.Based on the above, the corresponding experiments were conducted.The radical displacements at the different times were obtained at the characteristic points for the ektexines of the cylindrical steel shells.The measured results by electric probes are consistent with the deformation of the cylindrical steel shell after the experiments.
An electric probe measurement technique was proposed to measure the deformation undergone by the ektexines of the cylindrical steel shells subjected to the detonation of spherical explosive charges inside them.Numerical simulation was carried out to forecast the deformation of the steel shell ektexine at the section of the explosion center in the case of the spherical high-explosive charge equivalent to 120g TNT as well as 180g TNT.Based on the above, the corresponding experiments were conducted.The radical displacements at the different times were obtained at the characteristic points for the ektexines of the cylindrical steel shells.The measured results by electric probes are consistent with the deformation of the cylindrical steel shell after the experiments.
2014, 34(1): 120-124.
doi: 10.11883/1001-1455(2014)01-0120-05
Abstract:
For solving the high-overload problem existing during launching the scout-robot, the polyurethane foam was used as cushion material to reduce the overloads endured by the scout-robot.The energy-absorption capability of the polyurethane foam in the high-shock launching was discussed.Based on the structure of the robot protection shell and the properties of the cushion material, a mathematical model was established for the base-excited system with single degree of freedom.And the natural frequency of this system was analyzed as well as its amplification coefficient.An interior ballistics measurement system was developed to measure the acceleration curves of the scout-robot with and without cushion.The experimental results show that the system can produce resonance to make its acceleration increase when the natural frequency of the system is close to the excitation frequency of the launching device.And the natural frequency of the cushion system can be changed by adjusting the system parameters to reduce the amplification coefficient to less than 1and thus the cushion system can avoid resonance.
For solving the high-overload problem existing during launching the scout-robot, the polyurethane foam was used as cushion material to reduce the overloads endured by the scout-robot.The energy-absorption capability of the polyurethane foam in the high-shock launching was discussed.Based on the structure of the robot protection shell and the properties of the cushion material, a mathematical model was established for the base-excited system with single degree of freedom.And the natural frequency of this system was analyzed as well as its amplification coefficient.An interior ballistics measurement system was developed to measure the acceleration curves of the scout-robot with and without cushion.The experimental results show that the system can produce resonance to make its acceleration increase when the natural frequency of the system is close to the excitation frequency of the launching device.And the natural frequency of the cushion system can be changed by adjusting the system parameters to reduce the amplification coefficient to less than 1and thus the cushion system can avoid resonance.
2014, 34(1): 125-128.
doi: 10.11883/1001-1455(2014)01-0125-04
Abstract:
The experiments and the numerical simulations were carried out to investigate the characteristics in the initiation process of the TATB explosive by flyers.The initiation sequence was designed to initiate the high-density TATB explosive.The all-fiber displacement interferometer system for any reflector was used to measure the flyer velocities for the success and failure of the initiation in the TATB explosive, respectively.So the corresponding threshold flyer velocity was determined primarily.And the DYNA2Dprogram was employed to simulate the detonation process of the TATB explosive initiated by the flyer.The simulated results are consistent with the experiments.
The experiments and the numerical simulations were carried out to investigate the characteristics in the initiation process of the TATB explosive by flyers.The initiation sequence was designed to initiate the high-density TATB explosive.The all-fiber displacement interferometer system for any reflector was used to measure the flyer velocities for the success and failure of the initiation in the TATB explosive, respectively.So the corresponding threshold flyer velocity was determined primarily.And the DYNA2Dprogram was employed to simulate the detonation process of the TATB explosive initiated by the flyer.The simulated results are consistent with the experiments.
