FOX-7和RDX基含铝炸药的冲击起爆特性

为研究FOX-7和RDX基含铝炸药的冲击起爆特性,对其进行了冲击波感度试验和冲击起爆试验,结合冲击波在铝隔板中的衰减特性,确定了FOX-7和RDX基含铝炸药的临界隔板值和临界起爆压力,并通过锰铜压阻传感器记录了起爆至稳定爆轰过程压力历程的变化。结果表明,以Φ40mm×50mm的JH-14为主发装药时,FOX-7和RDX基含铝炸药临界隔板值分别为37.51和34.51mm,对应的临界起爆压力为10.91和11.94GPa;起爆压力为11.58GPa时,FOX-7炸药的到爆轰距离为25.49~30.46mm,稳定爆轰后的爆轰压力为27.68GPa,爆轰速度为8 063m/s;起爆压力为14.18GPa时,RDX基含铝炸药的到爆轰距离为17.27~23.53mm,稳定爆轰后的爆轰压力为17.16GPa,爆轰速度为6 261m/s。     

带壳B炸药在钨珠撞击下冲击起爆的数值模拟

基于L ee-T arver点火增长模型,对直径分别为9、14、18和25mm的钨珠撞击带钽壳B炸药的过程进行了数值模拟,计算出了引爆B炸药的阈值速度,计算值与试验值相符合。探讨了B炸药在钨珠撞击下的起爆机理,结果表明,随着钨珠尺寸的增大,引爆B炸药的钨珠撞击阈值速度呈指数规律减小;当钨珠以引爆阈值速度撞击炸药时,随着钨珠直径的增大,炸药发生爆轰的时间逐渐推后,爆轰增长速度逐渐变慢。从钨珠撞击引爆炸药的机制来说,炸药点火是压力波的峰值压力和持续时间共同作用的结果,峰值较低的压力波作用较长时间也可以引爆炸药。     

Explosive Initiation of Creative Processes in Nature

The paper deals with the construction of explosive–fill dams, of which Academician M. A. Lavrent'ev was an enthusiast. His contribution to the construction of the Alma–Ata mud dam is described. The experience of industrial explosions is used to show the possibility of including the potential of nature in human creative activity by means of explosion energy. Large–scale processes of rocksliding and formation of long–range rock avalanches produced by man–made and natural factors are considered. The development of a spontaneous landslide is described using a model of a rigid body with inhomogeneities. As a result, a unified approach to natural and man–made relief–forming processes is proposed. Recommendations for prediction and prevention of disastrous landslides are formulated.     

新型高能钝感炸药JBO-9X在较高冲击压力下冲击起爆过程的实验研究

采用高速扫描相机和楔形炸药构型,对新型高能钝感炸药JBO-9X的冲击起爆过程进行了实验研究;采用LS-DYNA软件对实验结果进行了数值模拟验证。结果表明,在6.9GPa的入射冲击压力下,JBO-9X炸药的冲击转爆轰时间为1.5μs,冲击到爆轰的距离为7.9mm;当冲击波刚进入炸药时,炸药发生化学反应的比例(λ)为0.2,随着冲击波进入炸药的距离增加,受试炸药中发生化学反应的比例逐步增加。在实验条件下,入射冲击波压力为6.85GPa时,JBO-9X炸药的冲击到爆轰距离为8.0mm。化学反应比例随冲击波进入炸药距离的增长曲线与实验基本相同。     

Shock Compression and Initiation of LX-10

LX-10 is a high energy density solid explosive consisting of 94.5% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 5.5% Viton A Binder pressed to 1.865 g/cm³ (98.4% of theoretical maximum density). In this paper the shock compression and initiation of chemical reaction in LX-10 by sustained shock pressures of 0.4 to 3 GPa are studied experimentally using embedded pressure and particle velocity gauges. The resulting pressure and particle velocity histories are evaluated theoretically using the ignition and growth reactive flow computer model of shock initiation and detonation. Manganin resistance and polyvinylidene fluoride (PVF₂) ferroelectric pressure gauges are both employed in the low pressure (0.4 – 0.7 GPa) shock compression experiments. Multiple manganin pressure and multiple electromagnetic foil particle velocity gauges measure the growth of reaction at various positions in LX-10 shocked to 1 – 3 GPa. The reactive flow modeling results imply that less than one percent of the LX-10 shocked to 0.4 – 0.7 GPa reacts in fifteen microseconds. For the higher pressure experiments, the ignition and growth model accurately calculates the pressure and/or particle velocity buildup in LX-10 as the reaction grows toward detonation. The LX-10 calculations are compared to those for the well-calibrated explosive PBX-9404, which contains 94% HMX and a reactive binder. Since it has the inert binder Viton A and better mechanical properties than PBX-9404, LX-10 is demonstrated to be significantly less reactive than PBX-9404 at these shock pressures. Therefore LX-10 is safer than PBX-9404 in many hazard and vulnerability scenarios to which solid explosives may be subjected.     

Flyer Plate Motion by Thin Sheet of Explosive

Acceleration of a metal plate by explosive energy at low value of charge to metal mass ratio has been studied by employing a new theoretical model based on uniform pressure and density of detonation products behind the flyer plate. Theoretical velocities of flyer plates have been compared with those measured by radiographic technique and found in good agreement. Comparing the relations for plate velocity, obtained from the present model and earlier Gurney model at low C/M values, an analytical expression for Gurney energy has been obtained in terms of detonation velocity of the explosive and adiabatic exponent of the detonation products.     

Initiation of Explosive Transformation of High Explosives under Low-Velocity Mechanical Impacts and Weak Shock Waves Due to Formation of Viscoplastic Flows

A key issue for explaining bursts and explosions of high explosives (HEs) under low-velocity mechanical impacts with registered time delays is the formation of local high-temperature regions. It is demonstrated by an example of HMX that the required temperatures should significantly exceed the HMX melting point and can be obtained only due to the work of viscosity forces in the liquid phase. In this case, however, it is necessary to ensure HE flow velocities greater than the primary impact velocities by several orders of magnitude. A mechanism of generation of such velocities is proposed: squeezing of the HE, which is heated on shear strains and plasticized, from the shear layer under the action of the pressure difference along the layer. Conditions of fast decomposition of the HE in the shear layer and conditions of an explosion of the surrounding HE are formulated.     

Model of Impact Initiation of Composite Explosive Solid Systems

A model of mechanical initiation of solid explosives, applicable for analysis of sensitivity of individual substances and composite explosives, is developed. The model includes a system of equations of work softening of a high explosive charge under an impact, resulting dissipative heating, and heat release due to chemical reactions between the components of the explosive mixture. The critical parameters and reaction kinetics were numerically calculated for initiation of charges consisting of a mixture of ammonium perchlorate and polymethylmethacrylate. The results are compared to experimental data on sensitivity of this mixture to the impact. Key words: high explosive, impact, explosion, impact sensitivity.     

Laser Initiation of Non‐Primary Explosive Detonators

Aiming to solve the problems caused by primary explosives in traditional detonators, a new kind of non‐primary explosive detonator based on the principle of flying plate detonator is invented. However, in some special circumstances, such as high temperature, strong radiation, strong magnetic field, overload, high‐pressure conditions, the non‐primary explosive detonator cannot work well because of the defects of its usual used initiating method like electric hot wire initiating devices, electric exploding bridge wire initiator, and initiating by a shock‐conducting tube. In this context, initiation by low energy laser is applied to non‐primary explosive detonator. After this combination, the non‐primary explosive detonator performs well in resisting high temperature, high pressure, overload, and electric interference.     

复合装药偏心起爆的爆轰波特性

为研究复合装药在偏心起爆条件下的爆轰波特性,采用转镜式高速相机狭缝扫描技术对装药表面的爆轰波形传播过程进行测量,得到爆轰波在狭缝位置的扫描曲线、时空坐标以及爆轰波阵面分布图.分析了复合装药爆轰会聚波的速度分布、形成机理及传播规律,提出偏心起爆条件下复合装药爆轰波阵面前沿为凹面会聚波,会聚波可以提高内层装药爆轰波的传播速度.     

Effect of Explosive Shock Waves on Ceramic Powders

Powders of several ceramic materials were subjected to explosive shock waves and changes in their physical properties were studied. Very fine particle sized SiC and B₄C could be produced without introducing impurities. Strong line broadening in the X-ray diffraction pattern of shocked powders was observed and correlated with lattice strain and crystallite size reduction. Shocked CaCO₃ turned blue when exposed to X rays. Shocked powders gave higher tapped densities, higher green densities after pressing, and were unusually responsive to sintering. Explosive shocking may be a unique way of "cold-working" ceramics and may permit subsequent control of their microstructure through primary recrystallization.     

固体炸药冲击起爆研究

为了研究固体炸药冲击起爆特性,对JO-9159炸药进行了隔板冲击加载实验,用高速摄影方法记录炸药冲击起爆过程;用解析计算方法分析了有机玻璃隔板的临界厚度值;建立了炸药冲击起爆模型,对起爆过程进行了数值模拟,计算了炸药在冲击作用下的压力历史,分析了JO-9159炸药起爆压力阈值和爆轰成长距离。     

Plastic Deformation in Alumina by Explosive Shock Loading

Spherical alumina powder, composed of α-Al₂O₃ and transitional alumina phases, was compacted by explosive shock loading with maximum pressures of 13 to 26 GPa and a maximum adiabatic temperature rise of ∼400°C. A final density >90% of theoretical was achieved. The powder densified primarily by plastic deformation, with only occasional particle fracture. Transmission electron microscopy showed dislocation densities of at least 10¹¹ cm⁻² in all phases and extensive twinning in transitional alumina phases.     

Initiation of a Porous Explosive by Overdriven Gas Detonation Products

This paper reports results of experiments on initiation and development of detonation in cylindrical charges of a porous explosive by overdriven detonation products of a gas mixture C₂H₂ + 2.5 O₂. Explosive charges with a bulk density of about 1 g/cm³ in fragile shells were studied. For PETN and RDX charges, the critical initial pressure of the gas mixture at which detonation initiation still occurs is determined and the pressures acting immediately on the charge are given. For PETN, critical initial pressures and initiation delays were measured for the first time for charges with particles of various diameters. The obtained dependence characterizes the following abnormal property of porous charges: there is an optimum particle size for which the explosive sensitivity is maximal. Streak records of selfluminosity for typical initiation modes are given. Mass velocity profiles in initiation waves at different depth of the charge are obtained using an electromagnetic procedure.     

炸药热冲击损伤破坏及超声波特性参量检测

进行了 JOB- 90 0 3炸药试样的热冲击试验和热冲击前后的超声波特性参量检测试验 ,观察并检测到试样在热冲击试验的不同阶段出现损伤破坏及超声波特性参量的具有一定典型性的变化。试验初步表明 ,初始损伤或裂纹对炸药的力学性能有十分明显的影响 ,超声波特征参量对炸药的损伤及破坏进一步表现出一些可识别的特征     

冲击波作用下炸药安全性QMU评估

为了对炸药冲击波感度进行量化评估,根据裕度和不确定度的量化(QMU)评估的通用框架和关键要素,研究了炸药安全性的QMU评估方法。按序贯试验方法设计了炸药的安全性试验,统计分析了炸药的起爆临界阈值、试验方差和响应概率,建立了隔板试验中冲击波作用下炸药安全性的QMU评估模型。通过隔板试验研究了炸药爆炸的临界隔板厚度和其他参数,利用Bruceton升降法试验和大样本量的Monte-Carlo模拟,得到炸药安全性的QMU评估的系列公式,计算了PBX-C炸药冲击波安全性要求的临界阈值Xth、均值μ、方差σ和XP估计的标准差,导出了给定置信水平时爆炸概率P相应点XP估计的不确定度区间,对冲击波作用下PBX-C炸药的安全性进行了初步QMU评估。     

A General Model for the Shock Initiation of Explosives

A general model for the shock initiation of explosive reaction in chemical explosives is proposed. The model is based on the concepts of: (1) the kinetics of decomposition in which ions and free radicals produced by the shock wave shear forces initiate chain reactions that contribute to and accelerate the decomposition produced by the thermally activated molecules; (2) the formation of statistically random reaction sites whose number in a specific explosive is a direct function of the shock pressure as the shock transits the explosive; and (3) a critical- energy-fluence requirement for initiation. This model appears to apply to explosive reaction in gases, liquids, and solids.     

Prompt Shock Initiation of Cased Explosives by Projectile Impact

Experimental results often show that a prompt shock response to projectile impact can be experienced by even relatively heavily cased explosives. This paper will discuss the predictive criteria that can be applied in such circumstances, and in particular will explore the different mechanisms which are present for rod and sphere impacts. Predicted initiation thresholds are shown to give good comparisons with experimental results, using, at most, two empirical shock sensitivity constants obtained from impacts of the uncased explosive.     

温度冲击试验技术在混合炸药中的应用研究

应用炸药温度冲击试验技术，在－５４～＋７１℃之间考察温度突变对几种典型的混合炸药药柱尺寸的稳定性及力学性能的影响。     

Shock Initiation of the CL‐20‐Based Explosive C‐1 Measured with Embedded Electromagnetic Particle Velocity Gauges

Hexanitrohexaazaisowurtzitane (CL‐20) is a high‐energy material with high shock sensitivity. The evolution of shock into the detonation of CL‐20 deserves academic attention and research. An embedded electromagnetic particle velocity gauge was used to study the shock initiation of detonation in a pressed solid explosive formulation, C‐1, containing 94 wt‐% epsilon phase CL‐20 and 6 wt‐% fluororubber (FPM). In conventional experiments, the magnetic field was generated using a pair of electromagnets with a complex structure and operation. A new device was designed to solve complex problems. This device comprised NdFeB magnets, pole shoes and magnetic yokes; using this technique, a uniform magnetic field could be created. A series of shock initiation experiments on high‐explosive C‐1 was performed, and the explosive samples were initiated at different intensity input shocks by an explosive driven flyer plate. In situ magnetic particle velocity gauges were utilized to detail the growth from an input shock to detonation, and the attenuation of particle velocity in unreacted C‐1 was also obtained in low‐intensity shock initiation experiments. Hugoniot data for C‐1 in the form of shock velocity D vs. particle velocity Up were obtained. A simulation model for shock initiation of C‐1 was established, and the particle velocity data from several experiments were used to determine the parameters required for the unreacted equation of state and ignition and growth reactive flow model for C‐1. These coefficients were then applied in the calculation of the initial shock pressure−distance to detonation relationship (Pop‐plot) for the explosive. Based on the results of experiments and simulations, the shock sensitivity characteristic of C‐1 was described.