子母式战术导弹子弹散布场的Monte-Carlo数字仿真

利用Ｍｏｎｔｅ－Ｃａｒｌｏ 方法,对子母式战术导弹空中抛撒后形成的子弹散布场和毁伤面积概率分布进行数字仿真研究,建立了散布场的数字仿真方法。建立了考虑重力影响的三维子弹弹道方程及其解。最后,以某种型号的战术导弹为例进行了仿真。     

Study on energy release characteristics of reactive material casings under explosive loading

Reactive Materials (RMs), a new material with structural and energy release characteristics under shock-induced chemical reactions, are promising in extensive applications in national defense and military fields. They can increase the lethality of warheads due to their dual functionality. This paper focuses on the energy release characteristics of RM casings prepared by alloy melting and casting process under explosive loading. Explosion experiments of RM and conventional 2A12 aluminum alloy casings were conducted in free field to capture the explosive fireballs, temperature distribution, peak overpressure of the air shock wave and the fracture morphology of fragments of reactive material (RM) warhead casings by using high-speed camera, infrared thermal imager temperature and peak overpressure testing and scanning electron microscope. Results showed that an increase of both the fireball temperature and air shock wave were observed in all RM casings compared to conventional 2A12 aluminum ally casings. The RM casings can improve the peak overpressure of the air shock wave under explosion loading, though the results are different with different charge ratios. According to the energy release characteristics of the RM, increasing the thickness of RM casings will increase the peak overpressure of the near-field air shock wave, while reducing the thickness will increase the peak overpressure of the far-field air shock wave.     

Enhancing the explosive characteristics of a Semtex explosive by involving admixtures of BCHMX and HMX

A well-known ternary plastic explosive, Czech Semtex 1H, contains a mixture of PETN and RDX softened by SBR. In this work, BCHMX was used to replace PETN in Semtex 1H to form Sem-BC+RDX. In addition, another mixture based on BCHMX and HMX as energetic fillers bonded by the polymeric matrix of Semtex 1H (Sem-BC+HMX) was studied. The particle size distribution of each individual explosive was determined to obtain the optimum mixing conditions. Friction and impact sensitivities were determined. The velocity of detonation was reported practically and the detonation properties were calculated by EXPLO5 code. The explosive strength of each sample was measured by the ballistic mortar test. The conclusion confirms that the velocity of detonation of Sem-BC+HMX was the highest in comparison with the prepared samples. Sem-BC+RDX has the least impact and frictions sensitivities. Sem-BC+RDX has higher detonation velocity, detonation properties and explosive strength than Semtex 1H. Addition of BCHMX in Semtex 1H as a replacement for PETN is the candidate to produce a high performance advanced Czech plastic explosive.     

Microstructural characterization of silicon carbide reinforced dissimilar grade aluminium explosive clads

Aluminium composites are inevitable in ship building, commercial and defence aircrafts construction due to their light weight, high strength to weight ratio, admirable properties and cost affordability. In this study, the microstructural characteristics of explosive cladded dissimilar grade aluminium (Al 1100-A1 5052) clad composites reinforced with silicon carbide (SiC) particles is presented. Microstructure taken at the interface by optical and scanning electron microscopes (SEM) revealed the formation of a silicon carbide layer between the dissimilar grade aluminium sheets. Though reaction layers were witnessed at few locations along the interface, the diffusion of atoms between the participant metals is not visible as confirmed by energy dispersive spectroscopy, elemental mapping, line analysis and X-ray diffraction (XRD). The variation in microhardness at various regions of the silicon carbide reinforced dissimilar aluminium explosive clad is reported. The increase in tensile strength of the SiC laced clad is also presented.     

A numerical study on the disturbance of explosive reactive armors to jet penetration

The disturbance of flat and V-shaped sandwich reactive armor configurations to shaped-charge jet is studied by a numerical approach. The disturbing and cutting effects of the two reactive armor configurations to the jet are successfully captured. The predicted disturbance characteristics and patterns are in fairly good agreement with the X-ray photographic observations. The residual depth of penetration into a semi-infinitive homogeneous steel target behind the reactive armor is computed for a series of jet/armor parameters. For the flat configuration, it is demonstrated that the residual penetration depth is not significantly reduced for a normal impact while it is reduced up to 75% for an oblique impact. In comparison, the V-shaped configuration reduces the penetration depth of the jet to 90%, and it is observed that the penetration depth is not sensitive to the V-shaped angle.     

Reaction degree of composition B explosive with multi-layered compound structure protection subjected to detonation loading

The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered com-pound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.     

Effects of nano-sized aluminum on detonation characteristics and metal acceleration for RDX-based aluminized explosive

Nano-sized aluminum(Nano-Al)powders hold promise in enhancing the total energy of explosives and the metal acceleration ability at the same time.However,the near-detonation zone effects of reaction between Nano-Al with detonation products remain unclear.In this study,the overall reaction process of 170 nm Al with RDX explosive and its effect on detonation characteristics,detonation reaction zone,and the metal acceleration ability were comprehensively investigated through a variety of experiments such as the detonation velocity test,detonation pressure test,explosive/window interface velocity test and confined plate push test using high-resolution laser interferometry.Lithium fluoride(LiF),which has an inert behavior during the explosion,was used as a control to compare the contribution of the reaction of aluminum.A thermochemical approach that took into account the reactivity of aluminum and ensuing detonation products was adopted to calculate the additional energy release by afterburn.Combining the numerical simulations based on the calculated afterburn energy and experimental results,the param-eters in the detonation equation of state describing the Nano-Al reaction characteristics were calibrated.This study found that when the 170 nm Al content is from 0％to 15％,every 5％increase of aluminum resulted in about a 1.3％decrease in detonation velocity.Manganin pressure gauge measurement showed no significant enhancement in detonation pressure.The detonation reaction time and reaction zone length of RDX/Al/wax/80/15/5 explosive is 64 ns and 0.47 mm,which is respectively 14％and 8％higher than that of RDX/wax/95/5 explosive(57 ns and 0.39 mm).Explosive/window interface velocity curves show that 170 nm Al mainly reacted with the RDX detonation products after the detonation front.For the recording time of about 10 μs throughout the plate push test duration,the maximum plate velocity and plate acceleration time accelerated by RDX/Al/wax/80/15/5 explosive is 12％and 2.9 μs higher than that of RDX/LiF/wax/80/15/5,respectively,indicating that the aluminum reaction energy significantly increased the metal acceleration time and ability of the explosive.Numerical simulations with JWLM explosive equation of state show that when the detonation products expanded to 2 times the initial volume,over 80％of the aluminum had reacted,implying very high reactivity.These results are significant in attaining a clear understanding of the reaction mechanism of Nano-Al in the development of aluminized explosives.     

Effect of energy content of the nitraminic plastic bonded explosives on their performance and sensitivity characteristics

Information about the forty nine nitraminic plastic bonded explosives (PBXs) and different nitramines were collected. Fillers of these PBXs are nitramines 1,3,5-trinitro-1,3,5-triazinane (RDX) and β-1,3,5,7-tetranitro-1,3,5-tetrazocane (β-HMX), cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole (bicyclo-HMX, BCHMX) and ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, CL-20) which are bonded by polyfluoro-elastomers, polydimethyl-siloxane, poly-glycidyl azide, polyisobutylene, polystyrene-butadiene, poly-acrylonitrile-butadiene and hydroxyl-terminated polybutadiene in addition to a melt cast compositions based on 2,4,6-trinitrotoluene. For thirty two of these PBXs the relationships are specified and analyzed between heats of their combustion and relative explosive strengths; by means of these relationships it might be possible to estimate, which groupings in the macromolecule of binder could be liable to their primary fission in the PBXs initiation. Similarly, for forty two of these explosives, the relationships are described and analyzed between their enthalpies of formation and impact sensitivities; here is especially attention paid to PBXs filled by BCHMX. Specific rate constants from Vacuum Stability Test (VST) of four nitramines and twenty PBXs are introduced into relationships with their enthalpies of formation. Regarding to all the mentioned cases, increasing of energy content of the studied explosives leads to increase of the relative explosive strength or initiation reactivity, respectively. Exception with the opposite trend, the outputs of VST are for BCHMX, where in PBXs are matrices with the esteric plasticizers or the energetic poly-glycidyl azide. Admixture of RDX or HMX, respectively, into the BCHX PBXs gives ternary PBXs whose thermal stability, in the sense of applied VST, is higher comparing to the original binary explosives.     

Performances and direct writing of CL-20 based ultraviolet curing explosive ink

A new type of explosive ink formulation that can be quickly cured was prepared with unsaturated polyester as binder,styrene as active monomer,2,4,6-trimethylbenzoyl-diphenylphosphine oxide as photoinitiator,and hexanitrohexaazaisowurtzitane (CL-20) as the main explosive.Then the explosive ink direct writing technology was used to charge the micro-sized energetic devices,the curing mechanism of the explosive ink was discussed,and the microstructure,safety performance and explosive transfer performance of the explosive ink molded samples were tested and analyzed.Results indicate that the composite material has a fast curing molding speed,its hardness can reach 2H within 8 min.The crystal form of CL-20 in the molded sample is still ε type.The CL-20 based W-curing explosive ink formulation has good compatibility,its apparent activation energy is increased by about 3.5 kJ/mol.The composite presents a significant reduction in impact sensitivity and its characteristic drop height can reach 39.8 cm,which is about 3 times higher than the raw material.When the line width of charge is 1.0 mm,the critical thickness of the explosion can reach 0.015 mm,and the explosion velocity is 7129 m/s when the charge density is 1.612 g/cm3.     

不可预见作战下排弹抢修力量编配分析

在资源有限的情况下,综合考虑某一区域不同机场之间的相互关系,从整体的角度合理分配排弹抢修资源,可以大幅提升区域内军队机场阵地的战场排弹抢修能力。本文通过建立数学模型,从整体的角度出发,分析区域内各机场的排弹抢修资源分配问题：首先,针对不可预见作战带来的新挑战,提出了新的机场排弹抢修作业流程,引出排弹抢修力量分配所面临的几个现实问题;其次,为解决提出的问题,建立计算排弹抢修时间的数学模型;最后,利用建立的模型依次对上述问题进行分析,并给出排弹抢修资源编配与力量建设的建议。本研究认为,军事机场排弹抢修力量应根据机场特点,合理分配排弹抢修资源;要以机场排弹抢修力量为主导,以外部支援力量为辅助,提升机场自身排弹抢修能力;可通过建设排弹抢修物资仓库和设置排弹抢修支援小组,提升多机场联动的排弹抢修能力。