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。     

用电磁粒子速度计实验研究一种TATB基钝感炸药的冲击响应

针对一种新的TATB基钝感炸药(Tx),应用组合式电磁粒子速度计(EMV)测试技术,测量了炸药直接加载、增加有机玻璃隔板以及炸药驱动飞片3种加载状态下炸药内部的粒子速度历程和冲击波轨迹。根据测试结果,分析了不同加载压力下炸药的冲击响应过程。结果表明,炸药直接加载时,加载压力最高,Tx钝感炸药很快达到爆轰状态,到爆轰距离约为1.5mm;在增加有机玻璃隔板、加载压力为14.2GPa时,与直接加载时炸药粒子速度一致,Tx钝感炸药的到爆轰距离明显增加,约为5mm;在炸药驱动飞片、加载压力为9.5GPa时,Tx钝感炸药的粒子速度逐渐降低,存在一定钝化现象,到爆轰距离达到20mm以上。     

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。     

GI-920炸药爆轰波阵面的光纤探针测量

利用熔石英在冲击作用下的发光特性开发了一种测量冲击到达时间的光纤探针技术。当爆轰波阵面到达光纤探针端面时会产生一个瞬时光信号，经光纤传输到光电探测器，变换为电信号，再由示波器记录，通过判读就可以知道冲击波或飞片到达光纤探针的时刻。采用芯径0．3mm的石英光纤探针阵列对一点起爆的爆压为10GPa的GI-920炸药的爆轰波阵面进行了测量，测量到3条不同直径上的波形，并利用所测数据绘出爆轰波阵面的三维形状图。结果表明，随着测试半径增大，爆轰到达时间分散性明显增加，爆轰波阵面的倾角也增大。实验所得信号的上升时间均小于4ns，说明光纤探针技术为炸药爆轰时间参数的测量提供了一种新的高精度的测试手段。     

炸药爆轰时的能量释放

炸药的一个重要特征就是在一定的外界作用下能发生爆轰化学反应,在极短的时间内放出巨大的能量,使爆轰产物达到极高的温度和压力而完成破坏或抛掷作用。单位质量炸药在爆轰时放出的能量叫爆轰能(E_d),这一能量如用热量的单位表示就叫作爆轰热(Q_d)。目前已经能够用实验的方法,测定炸药爆轰后产物在一定条件下冷却到室温时放出的热     

JBO-9021炸药初始密度对爆轰波阵面曲率效应的影响

采用高速扫描相机及电探针,在室温环境下对不同初始密度(1.894~1.901g/cm3)、不同半径(5.0、7.5、15.0mm)的钝感炸药JBO-9021药柱开展了曲率效应实验,获取了拟定态爆轰波阵面形状及波速,分析了其随炸药柱密度及半径的变化。结果表明,随着炸药JBO-9021的初始密度由1.894g/cm3增至1.901g/cm3,3种不同半径JBO-9021药柱的爆轰波拟定态波速均增大,拟定态波阵面形状变得更为平坦,波阵面中心点与边界点之间的波到达时间差降低;在小曲率范围内(κ0.2mm-1),JBO-9021药柱爆轰波波阵面法向波速Dn与当地曲率κ的关系(Dn(κ)关系)不受药柱半径及密度的影响,当曲率κ0.2mm-1时,Dn(k)关系随药柱半径及炸药密度呈现离散趋势,药柱半径及初始密度共同影响爆轰波波阵面大曲率的Dn(κ)关系。     

超压测试方法对炸药TNT当量计算结果的影响

用地面和空中冲击波超压测试系统测定了TNT和B炸药爆炸的马赫反射波超压和入射冲击波超压,计算得到不同测试条件下TNT爆炸冲击波超压的经验公式和B炸药的TNT当量。结果表明,马赫反射波超压大于入射冲击波超压,马赫反射波超压与入射冲击波超压比值随实验中对比距离的增加而增加。由马赫反射波超压和入射冲击波超压计算得到的B炸药TNT当量比分别为1.40和1.32。认为以空中入射冲击波超压测试结果计算得到的TNT当量更真实。     

密度对压装B炸药燃烧转爆轰性能的影响

以常规武器中常用的B炸药为研究对象，采用电探针及压力传感器测量技术，在相同的实验条件下分别对3种不同密度固体压装B炸药（m（TNT）；m（RDX）=40：60）的燃烧转爆轰性能进行了实验研究。B炸药的密度范围为1．597～1．681g／cm^3。实验结果表明，在相同的约束条件下，炸药密度对其燃烧转爆轰（DDT）性能有较大影响。不同密度炸药的DDT性能不同。较低密度的炸药更容易发生DDT现象，固体压装B炸药存在一个燃烧转爆轰的临界密度值。在较强的约束条件下（45号钢管，内径20mm，外径64mm，长500mm），密度为1．597g／cm^3的B炸药发生了DDT现象，诱导爆轰距离为295～310mm。     

壳体对炸药水下爆炸近场特性的影响

为了研究壳体对炸药水下爆炸近场特性的影响,在水下进行了Φ25mm圆筒试验与Φ25mm裸药柱滑移爆轰试验,对比分析了带壳装药、裸装药的冲击波迹线与壳体、气泡的膨胀迹线。结果表明,壳体对炸药爆炸后冲击波的衰减作用较为明显,带壳装药水下爆炸冲击波波阵面压力与冲击波传播速度以相对较低的初始值(0.9GPa,0.78mm/μs)近似保持不变,而裸装药水下爆炸冲击波波阵面压力与冲击波传播速度从较高初始值(8.5GPa,0.92mm/μs)以指数形式快速衰减;不同膨胀时期壳体对膨胀过程的影响不同,导致水下爆炸初期(0～5μs)与后期(20μs以后)带壳装药壳体的膨胀速率低于裸装药气泡的膨胀速率,水下爆炸中期(5～20μs)带壳装药壳体的膨胀速率高于裸装药气泡的膨胀速率。     

冲击加载下PBX的点火特性与力学特性间的关系

为研究撞击加载下无CT可见疵病的高聚物黏结炸药(PBX)的点火特性,利用大落锤实验研究了PBX在冲击加载时的力学响应和点火机制;采用ANSYS/LS-DYNA软件模拟计算了400kg落锤、2 500mm落高撞击加载下PBX的力学响应特性,探讨了PBX力学特性与其点火特性间的关系。结果表明,模拟加载应力曲线与实验测试曲线高度吻合;同一落高下,弹性模量为1.12~4.36GPa时,随着PBX弹性模量的增加,作用在PBX上的最大应力增加,PBX的最大应变率增大,发生点火的概率增加。为了增加PBX的加载安全性,PBX围压加载模量的最佳值应调整到1.12GPa。     

Reaction Zones of Detonating Solid Explosives

The reaction zones of normal and overdriven detonation waves in a number of solid HE were studied by recording the shock–wave luminosity in chloroform placed at the end of a high–explosive (HE) charge. The data obtained have led to some conclusions on the regularities of HE decomposition in a detonation wave. Thus, in a powerful solid HE, the heterogeneity of the charge plays a decisive role in the formation of a chemical spike. In this case, the time of reaction of heterogeneous HE correlates with the Jouguet pressure rather than with the sensitivity of the HE. The experimental parameters of the chemical spike are in good agreement with calculations on an extrapolated shock adiabat of the HE. This, however, does not indicate that the fraction of the HE decomposed directly at the detonation front is small but only shows that it depends smoothly on the front parameters. In overdriven detonation waves, an increase in the overcompression pressure is accompanied by an increase in the fraction of the HE decomposed directly at the front, and with a relatively large increase in pressure, the chemical spike completely disappears. In TATB and TATB–based HE, this occurs at a pressure of 40 GPa.     

Effect of Al/O Ratio on the Detonation Performance and Underwater Explosion of HMX‐based Aluminized Explosives

The performance of detonation and underwater explosion (UNDEX) of a six‐formula HMX‐based aluminized explosive was examined by detonation and UNDEX experiments. The detonation pressures, detonation velocities, and detonation heat of HMX‐based aluminized explosive were measured. The reliability between the experimental results and those calculated by an empirical formula and the KHT code was verfied. UNDEX experiments were carried out on the propagation of a shock wave and a bubble pulse of a 1 kg cylindrical HMX‐based aluminized explosive underwater at a depth of 4.7 m. Based on the experimental results of the shock wave, the coefficients of similarity law equation for the peak pressure and attenuation time constant of shock wave were in acceptable agreement. The bubble motion during UNDEX was simulated using MSC.DYTRAN software, and the radius time curves of bubbles were determined. The effect of the aluminum/oxygen ratio on the performance of the detonation and UNDEX for an HMX‐based aluminized explosive was discussed.     

Detonation Failure Characterization of Homemade Explosives

Typically characterizing home made explosives (HMEs) requires many large scale experiments, which is prohibitive given the large number of materials in use. A small scale experiment was developed to characterize HMEs such as ammonium nitrate‐fuel oil mixtures. A microwave interferometer is applied to small scale confined transient experiments, yielding time resolved characterization of a failing detonation that is initiated with an ideal explosive booster charge. Experiments were performed with ammonium nitrate and two fuel compositions (diesel fuel and mineral oil). It was observed that the failure dynamics were influenced by factors such as the chemical composition, confiner thickness, and applied shock wave strength. Thin steel walled confiners with 0.71 mm wall thickness experienced detonation failure and decoupling of the shock wave from the reaction zone. Confiners with a wall thickness of 34.9 mm showed a decrease in propagation speed and a steady reactive wave was achieved. Varying the applied shock strength by using an attenuator showed corresponding changes in the initial overdriven reactive wave velocity in the HMEs. The distance to detonation failure was also shown to depend on the attenuator length when thin wall confinement was used. This experimental method is shown to be repeatable and can be performed with little required material (about 2 g). The data obtained could be useful to model development and validation, as well as quantifying detonability of materials.     

Effect of an inert high-modulus ceramic wall on detonation propagation in solid explosive charges

The effect of an intert high-modulus ceramic wall on detonation propagation in charges of a solid heterogeneous explosive was investigated experimentally and numerically. Subdetonation pressures occurred at the boundary between the wall and the explosive for the conditions investigated. Here the detonation velocity increased, and the mass velocity and the pressure at the detonation front decreased, which is explained by the indirect effect of an overtaking wave into the unreacted explosive and the chemical reaction zone. Transverse waves, which affect the detonation parameters, propagate perpendicular to the detonation front with a velocity of ∼6 km/sec. The initial decomposition rate of the explosive directly after the compression shock determines the degree of the transverse-wave effect. Novosibirsk State Technical University. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 5, pp. 107–114, September–October, 1994.     

Desensitization of pressed RDX/paraffin and HMX/paraffin compounds by multiple shock waves

Multiple shock initiation of detonation in pressed RDX/paraffin and HMX/paraffin compounds is studied. If the explosive is preshocked by a weak shock wave, the effect of desensitization is observed, which is detectable by two features. First, a weak reaction appears behind the second shock wave. Second, the run to detonation increases by 100% for pressed RDX. Experiments with the samples of pressed RDX show that the run to detonation in preloaded explosive can be estimated from the distance at which the second shock wave overtakes the first weak shock; the run to detonation expected for the second shock wave, from Pop-plot data.Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 2, pp. 114–124, March–April, 1995.     

Loading of an emulsion by high-velocity plate impact

A pure emulsion based on an aqueous solution of ammonium nitrate placed in a steel tube 114 mm in inner diameter was shock loaded. The achieved dynamic pressure of 30 GPa, far exceeding the calculated detonation pressure, did not lead to the development of an explosive process.