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Abstract:To furtherly improve the penetration capability of explosively formed penetrator(EFP), a type of cone-arc liner which can form long rod-shaped compacted EFP was proposed based on the arc section design of large cone angle liner structure. The difference in collapse process for cone-arc liner and the traditional large cone angle liner as well as arc-cone liner was analyzed. The influences and regulars of cone-arc liner structure parameters (curvature radius, cone angle and wall thickness) on the formation parameters of penetrator, such as EFP velocity, length-diameter ratio and compactness, were calculated and obtained by LS-DYNA simulation software. The range of each parameters of optimum EFP are gained: the curvature radius is 1.1-1.3 times of charge diameter, the cone angle is 155°-160°, and the wall thickness is 0.04-0.046 times of charge diameter. And a kind of cone-arc liner structure that can form EFP with length-diameter ratio as 2 and compactness as 0.88 was designed and obtained.

Abstract:To enhance the damage probability of munitions at various encounter distances, a faceted prismatic warhead composed of flat faces and convex faces is numerically studied in this work, and the dispersion patterns and lethality parameters of fragment beams from different faces are analyzed. The results reveal that this warhead structure could produce two types of fragment beams. One is the fragment beam with high speed and small scattering angle, and the other shows low speed and wide coverage. These fragment beams are suitable for attacking targets at different missing distances. The asymmetrical initiations could enhance the fragment velocity of flat face by 21.68%, reduce the dispersion angle of 3.38° and improve the lethality of fragment opposite to detonating point without changing the property of producing two kinds of fragment beams. The lateral two line initiations could change the fragment dispersion angle of the flat face of 4.94° without reducing the velocity of the fragment, which is higher than other initiations. Under large warhead-target missing distance, this change could alter the aiming direction and improve the damage probability.

Abstract:To enhance the damage effectiveness of anti-light armor target ammunition, a kind of variational-wall-thickness arc-cone liner with low-density loading material was proposed. The influence law of each cone angle on explosively formed projectiles (EFP) forming and the penetration effect of EFP on target plate were analyzed by finite element software LS-DYNA. The curve of EFP forming parameters with each cone angle was obtained by fitting. Results show that when the inner cone angle α₁ of liner takes 166°-170.2°, the inner cone angle α₂ of filler takes 160°-166°, the outer cone angle α₃ of filler takes 140°-152°, the outer cone angle α₄ of liner takes 132°-140°, the EFP forming speed is fast and forming effect is good. The α₃ has the greatest influence on the forming speed, length and radial dimension of EFP, and the α₁ has the greatest influence on the center thickness of EFP. Based on the research results, the structure of the liner was optimized. The optimized liner can form an EFP with distinct penetrator with enhanced lateral efficiency(PELE) effect, which expands the hole when penetrating the target plate and forms some high-speed fragments in the target interior to cause secondary damage after penetrating the target plate.

Abstract:The tear bomb is a kind of non-lethal anti riot bomb. To study its non-lethal efficiency size, the armed police RS97-2 type tear bomb was used as the research object. The diffusion process of aerosol smoke for the tear bomb was studied by using Gaussian diffusion model. The change rule in the concentration and smoke radius of CS tear agent at the time of smoke diffusion was analyzed. The simulation and calculation were carried out by written software using Matlab. The effective area of the aerosol smoke diffusion of tear bomb obtained was used as a measurement index of its non lethal efficiency. Results show that when the wind speed is 2 m·s^-1, the effective action area range of aerosol smoke for a tear bomb with tear agent charge of 20 g can reach 453.7 m².

Abstract:CH₃NH₂·HCl was used to replace NH₄NO₃ as an additive in the reaction of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DPT) in fuming nitric acid, and the effect of CH₃NH₂·HCl on the formation of 1-nitroso-3,5,7-trinitro-1,3,5,7-tetraazacyclooctane (MNX) was investigated. The process of preparing MNX by CH₃NH₂·HCl promoting the reaction of DPT with fuming nitric acid was studied. The effects of loading amounts of fuming nitric acid and CH₃NH₂·HCl, reaction temperature and reaction time on the reaction were investigated. Results show that the optimum reaction conditions determined by orthogonal experiments are： n (DPT)∶n(CH₃NH₂·HCl)=1∶2.5，reaction time 10 min and reaction temperature -25 ℃. Under the optimum reaction conditions, the yield of MNX is 78.5%. This method avoids using NaNO₂ solution and N₂O₄ as nitroso resource and simplifies the preparation process of MNX. The waste liquid is easy to be treated. The recovery of nitric acid is 75%. CH₃NH₂·HCl can promote the reaction of DPT with fuming nitric acid more significantly than NH₄NO₃. A possible mechanism of promoting the reaction of DPT and fuming nitric acid via decomposing CH₃NH₂·HCl (or NH₄NO₃) into CH₃NH₂ (or NH₃) as a Lewis base catalyst is proposed, which involves the process of nitrous acid formation from nitric acid through a redox reaction as nitroso resource.

Abstract:A new compound methyleneaminonitroguanidine (MANG) was synthesized using aminoguanidine （ANQ）and formaldehyde as raw materials, and the reaction process was analyzed. The crystal structure of MANG was analyzed by an X-ray single diffractometer. Results show that the crystal belongs to an orthorhombic crystal system. Its space group is P_nn2. Each unit cell contains four MANG molecules, and the crystal density is 1.63 g·cm^-3. Thermal behaviors of MANG were studied by differential scanning calorimetry(DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG). MANG presents only one intense exothermic decomposition process. At a heating rate of 5 ℃·min^-1, the decomposition peak temperature and exothermic quantity of MANG are 170.9 ℃ and 1440 J·g^-1, respectively. The standard molar enthalpy of combustion and the standard molar enthalpy of formation of MANG obtained by calculation are -1526.09 kJ·mol^-1 and 33.81 kJ·mol^-1, respectively. The detonation velocity 7.1 km·s^-1 and detonation pressure 20.9 GPa of MANG predicted by Kamlet-Jacobs(K-J) equation are less than those of ANQ, but higher than those of TNT. The impact sensitivity(>7.9 J) of MANG is lower than that of ANQ(3 J) and RDX(7.4 J).

Abstract:To prolong the storage life of binder, the poly(glycidyl azide) ether(GAP)-based binders with self-healing performance were firstly synthesized by introducing disulfide functional group into an azide binder through an one-step method. Fourier transform infrared spectroscopy(FTIR), X-ray diffractometry(XRD) and optical microscopy were used to characterize its structure and surface topography characterization. On this basis, the self-healing efficiency under different self-healing temperature and different self-healing time was examined through the change of tensile strength before and after self-healing. Results show that the synthesized GAP-based self-healing binder has a polyurethane structure, the surface cracks of self-healing binder are completely healed after 24 h at 60 ℃. Increasing the temperature and prolonging the self-healing time are helpful to improve the self-healing efficiency. At the same time, the self-healing efficiency is firstly improved and then decreased with increasing mass fraction of the cross-linking agent, in which, the self-healing efficiency for the formula with a cross-linker mass fraction of 8% can reach 98%. Compared with control sample with the self-healing efficiency as 61.7%, which proves that the introduction of disulfide functional groups can improve the self-healing efficiency of the system.

Abstract:Based on the regulating of nanostructure on the properties of materials, the nanostructure of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was constructed by solvent/non-solvent method. Through strong nonsolvent effect and temperature effect,the keel-like nanostructure TATB was prepared.The microstructure of the sample was observed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) and the crystal phase and particle size distribution of the sample were measured by X-ray diffraction (XRD) and Laser Particle Size Analyzer. The results show that the whole morphology of obtained sample is keel-like crystalline. And the crystal form does not change compared with the raw material and the size distribution is from 70 to 400 nm. The thermal analyses at different heating rates show that the thermal decomposition peak temperature of keel-like nanostructure TATB is 1.54-2.91 ℃ earlier than that of raw TATB, the apparent activation energy(E_a) is increased by 0.29 kJ·mol^-1, and the sensitivity to thermal stimulation is decreased. The thermal decomposition mechanism of keel-like nanostructure TATB obtained by differential method calculationis random nucleation (a core for a particle), whereas the raw material is three-dimension diffusion and its kinetic equation is Jander equation with sphericalsymmetry.

Abstract:To simplify the production process of ruthenium oxide(RuO₂) ignition bridge, improve the output energy and meet the requirements of low energy ignition and rapid response, the 30 kinds of V-type RuO₂ ignition bridges with different structure size were designed and manufactured by a low-temperature co-fired ceramic(LTCC) technology. The electro-explosion properties of the bridge under constant-voltage excitation were investigated. The ignition ability of B/KNO₃ mixture was evaluated according to the ignition test results of B/KNO₃ mixture. The results show that the design of V-type structure is conducive to improving the current density in the bridge area and forming hot points in the narrowest part of the V-type bridge, which is conducive to reducing the energy required by electro-explosion.The angle, length/width ratio and width of the V-type RuO₂ ignition bridge have great influence on electro-explosion performance. Under 40 V constant-voltage excitation, when the angle, length/width ratio and width of the narrowest place of V-type RuO₂ ignition bridge are 60°, 0.43 and 100 μm, respectively, the input energy required by electro-explosion is small, its value is 1.47 mJ, the output energy is maximum, its value is 8.46 mJ, which can ignite B/KNO₃ mixture.

Abstract:To improve the ignition ability of semiconductor bridge (SCB), especially the ability to ignite insensitive compositions, Al/CuO_x multilayer film was fused and combined with semiconductor bridge by magnetron sputtering technology to form an energetic ignition device and the ignition sensitivity and ignition ability of the energetic ignition device were studied. The micro morphology and composition of Al/CuO_x multilayer films were studied by scanning electron microscopy (SEM), X-ray energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). Results show that the copper oxide film mainly exists in the form of black copper ore （Cu₂¹⁺ Cu₂¹⁺O₃）; the mass fractions of Al, Cu and O in the multilayer film are 28.8%, 32.5% and 38.7% respectively, and the ratio of Al to Cu atom is close to the theoretical ratio of 1∶1; the results obtained by differential scanning calorimeter(DSC) show that the quantity of heat release of Al/CuOx multilayer film is about 2175.4 J·g^-1. The burning rate of Al/CuO_x multilayer film is measured by high-speed photography is about 3.0 m·s^-1. The 50% ignition voltage of the energetic ignition device measured by Lanley′s method is 8.45 V and 99.9% ignition voltage is 12.39 V. The ignition ability experiment shows that when the ignition gap is 4 mm, the energetic device can ignite the insensitive ignition composition of B/KNO₃ tablets, which significantly improves the ignition ability of the semiconductor bridge.

Abstract:To investigate the characteristics and laws of energy releasefor Al/Ni reactive multilayer films(RMFs), Al/Ni RMFs initiator with double “V” type angle was fabricated by a micro-fabrication method and its characteristics and laws of energy release under 47 μF solid tantalum capacitor discharge excitation were studied. When electric explosion testing, the self-developed ALG-CN1 energy storage discharge detonator was used as an excitation power source. A 47 μF solid tantalum capacitor with a charging voltage of 10 V to 45 V was used. A high-speed camera（HG-100K）was used to observe the firing process of the initiator. A digital oscilloscope（LeCroy44Xs， 4 channnels）was used to record the current and voltage curves of the initiator.Results show that the electrical explosion process of Al/Ni RMFs initiator can be divided into three stages according to the change rate of current（dI/dt）：energy storage of parasitic inductance, electrical explosion of initiator and plasma heating. Comparison with NiCr film initiator of same bridge type,under the same excitation condition of 30 V/47 μF, the fabricated Al/Ni RMFs initiator has high output energy and long spark spattering distance after electrical explosion. The parasitic inductance of the firing circuit plays an important role in the initiation of the initiator. The output energy of Al/Ni RMFs initiator during electric explosion mainly comes from two parts： the input energy of capacitor and the chemical energy released by energetic film. When the excitation voltage is 30 V, the chemical energy contributes to the output energy of Al/Ni RMFs initiator is higher, which can reach 40% of the total output energy.

Abstract:A rapid component detection method of modified Composition B was studied by near infrared spectrum technology. The quantitative models of main components TNT and RDX were established by partial least squares（PLS）method. Results show that the coefficients of determination of cross-validation （R²）of established models are 0.9611, 0.9415, respectively. The root mean square errors of cross-validation (RMSECV) are 0.478%, 0.501%, respectively, and the root mean square errors of prediction (RMSEP) of external-validation are 555%, 521%, respectively, showing that the established quantitative model has high accuracy and precision. The calculated results of t-test performed by determined values of near infrared method and reference values of the standard analysis method are t_RDX=1.03, t_TNT=0.72, respectively. Their t values are smaller than the critical value t₉=2.26 (α₉=0.05), revealing that there is no significant difference between the near infrared spectroscopy and the standard analysis method.

Abstract:Each technology upgrading of Exploding Foil Initiator system (EFIs) is accompanied with the innovation of design concepts and manufacture processes, especially the technologies of Micro Electro Mechanical System (MEMS) and Low Temperature Co-fired Ceramics (LTCC) greatly promote the development of Micro Chip Exploding Foil Initiator system (McEFIs). The advantages and disadvantages of Micro Chip Exploding Foil Iinitiator (McEFI) fabricated by two kinds of processes were briefly analyzed. The working performances of several planar high-voltage switches in Capacitor Ddischarge Unit (CDU) were listed, and the feasibility of manufacture idea and research method of the switch is obtained. The research progress at home and abroad based on the preparation of MEMS process and LTCC process, and the study of McEFI, planar high-voltage switch as well as planar high-voltage switch integrated with McEFI was summarized respectively. Key research directions were put forward. In-depth research of the fabrication of McEFI and its planar high-voltage switch by the MEMS process will achieve engineering application. The planar high-voltage switch & McEFI with monolithic structure can be fabricated by LTCC technology.

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