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。     

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。     

RDX基铝薄膜炸药与铝粉炸药水下爆炸性能比较

为了减少铝粉炸药在生产过程中因铝粉对环境污染,降低铝粉炸药的撞击感度,提高含铝炸药的成型性及力学性能,将RDX用铝薄膜分层包裹得到新型的铝薄膜混合炸药。将铝薄膜混合炸药与铝粉炸药进行水下爆炸实验与爆速实验,得到两种炸药的爆速与压力时程曲线,经过分析计算得到两种炸药的压力峰值、冲量、冲击波能、气泡脉动周期与气泡能。结果表明：铝薄膜炸药药柱的轴向为RDX与铝薄膜独立贯通的结构,有利于降低混合炸药中添加物对基体炸药爆轰波传播的影响,从而使铝薄膜混合炸药的爆速高于铝粉炸药,导致铝薄膜炸药的冲击波损失系数高于铝粉炸药,使铝薄膜混合炸药的总能量、比气泡能与铝粉炸药相当情况下,其比冲击波能却降低了10.16%～10.33%,计算过程说明铝薄膜混合炸药的C-J压力计算公式具有合理性。     

炸药的冲击波感度——隔板试验

文中叙述了建立隔板试验的必要性,试验装置及数据处理方法。并列出了八种炸药样品的制备方法、密度、空隙度、爆炸50%几率的隔板厚度和起爆点的延迟距离的试验结果。初步探索了装药密度、试验环境温度对炸药冲击波感度的影响,并进行简单的讨论。     

炸药的冲击波感度——隔板试验

文中叙述了建立隔板试验的必要性,试验装置及数据处理方法。並列出了八种炸药样品的制备方法、密度、空隙度、爆炸50％几率的隔板厚度和起爆点的延迟距离的试验结果。初步探索了装药密度、试验环境温度对炸药冲击波感度的影响,並进行简单的讨论。     

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。     

复合载荷作用下TATB基PBX炸药药柱的损伤试验研究

为研究损伤炸药的安全性,在温度载荷和机械载荷的复合作用下,对TATB基PBX炸药药柱进行了较轻微和较强烈两种不同程度的损伤试验。测试了损伤前后PBX药柱的密度、超声波声速和增益值变化,采用隔板试验测试了冲击波感度。结果表明,经两种复合载荷作用后药柱的密度分别减小0.15%和2.16%,超声波声速减小0.97%和7.87%,增益值增加43.32%和49.07%;50%爆轰隔板厚度分别增加约2.08%和30.21%,表明复合载荷作用越强烈,药柱密度和声速值减小越明显,损伤越严重,冲击波感度越高。     

CL-20基含铝炸药组分微结构对其爆炸释能特性的影响

为了改善铝粉在CL-20基含铝炸药中的反应动力学特性,利用溶剂-非溶剂法制备了CL-20/Al复合颗粒,实现了CL-20与Al在微结构上的紧密结合,通过直接法制备了由CL-20/Al复合颗粒构成的组分质量分数为85%CL-20/10%Al/5%黏结剂的含铝炸药,并与常规法制备的相同组成的CL-20基含铝炸药进行了机械感度、爆热、爆炸罐试验和圆筒试验等结果的对比。结果表明,CL-20/Al复合颗粒会使含铝炸药的撞击感度略有提高,而摩擦感度不变,但总体上对机械感度影响不大;通过CL-20/Al在微结构上的复合,缩短了Al粉与爆轰产物之间的扩散距离,可以显著改善Al粉的反应动力学性能,提高Al粉在含铝炸药爆炸过程中的反应完全性,促使部分Al粉在爆轰区内参与反应,相比于常规法制备的相同组成的含铝炸药,可使含铝炸药的爆热从6787J/g提高至6930J/g,爆炸罐内爆炸场最高温度从544.3℃提高至661.2℃,格尼系数由2.88mm/μs提高至3.10mm/μs。     

LX-04炸药的撞击感度研究

通过铝飞片对LX-04钝感炸药的冲击，测定了其常温下及在170℃时的冲击感度，并给出了LX-04的凝聚态和爆轰产物的状态方程和点火与引爆模型，理论计算表明，方程中的参数与试验结果符合得很好。对比LX-04在不同温度下的撞击感度，得出LX-04在温度升高时相应地撞击感度也有所增加的结论并分析了撞击感度增加的原因。     

EAK基熔铸分子间炸药的能量和撞击感度

通过水下爆炸试验研究了RDX和HMX对EAK基熔铸分子间炸药水下能量的影响。结果表明,RDX和HMX对EAK基混合炸药起到明显的增能作用,但对含铝和非含铝体系有不同的作用效果。爆速和撞击感度测定表明,EAK—RDX混合炸药爆轰的理想化程度和稳定性及撞击感度随RDX含量的增加而增加。从能量和撞击感度两个方面综合考虑,RDX的较佳加入量应为20％～30％。     

Shock to Initiation Characters of Heated Explosives with Different Confinement

Heated explosives might undergo thermal expansion and/or phase transition, which affects their shock sensitivity. Therefore, investigating the effect of temperature on the shock initiation properties of explosives would provide valuable safety guidelines for their transportation and handling. In this study, an experimental detonation device that achieved homogeneous heating of the explosive test sample while avoiding unintended heat transfer to the donor was designed and constructed. The device allowed to perform flyer impact tests on PBXC10 at different temperatures and using different confinement conditions. The generated experimental pressure history curves were used to calculate the parameters of the I&G model and determine their relationships with the sample temperature. The fully parameterized I&G model enabled predicting the shock initiation properties of PBXC10 at temperatures where experimental data were unavailable. It was concluded that increased sample temperatures would lead to a shorter run distance to detonation, faster propagation of the detonation wave and enhanced shock sensitivity of the explosive. It was also demonstrated that unconfined PBXC10 exhibited significantly greater shock sensitivity compared to its partially and completely confined counterparts.     

铝粉含量对梯铝炸药爆压和冲击波参数的影响

测试了以TNT为基不同含量含铝炸药的爆压和空中爆炸冲击波参数,通过分析铝粉对炸药爆压、空中爆炸参数和爆炸冲击波超压的影响,建立了爆压与铝氧比的关系曲线、5种TNT基含铝炸药的冲击波相似律方程和TNT/Al炸药的爆压与空中爆炸冲击波超压的关系式.结果表明,随着铝粉含量的增加,炸药的爆压呈指数衰减,近距离的冲击波超压也快速减小,但爆炸场温度和爆炸火球的直径及持续时间会增大.     

Effect of Scale and Confinement on Gap Tests for Liquid Explosives

The factors influencing initiation of detonation in gap tests for liquid explosives are investigated experimentally. A calibrated donor charge (nitromethane) and PMMA attenuator disk arrangement are used to transmit shocks of known strength (2–10 GPa) into a test explosive of nitromethane sensitized with 5% diethylenetriamine. The test explosive is contained in capsules of different wall materials (PVC, Teflon, aluminum), and the dimensions of the charges vary from 25 mm to 100 mm in diameter. For the small‐scale charges, the presence of the confining wall of the test capsule is seen to have a pronounced effect on the detonation initiation. Certain wall materials (PVC, Teflon) exhibit a multi‐valued critical gap thickness, meaning that a weaker shock may result in initiation while a stronger shock does not. The effect of the wall materials could not be correlated with their acoustic or shock impedance, and the only way to eliminate these effects was to make the diameter of the test charge larger than the donor charge. When the size of the donor charge was increased, the critical pressure required for initiation decreased. These results could be correlated to “ideal” shock initiation experiments that use flyer plates as shock sources assuming that lateral rarefactions quench detonation initiation if they reach the central axis of the charge before the onset of detonation is complete.     

Numerical calibration of donor systems for some GAP tests

Numerical models of various donor/attenuator systems utilized in gap tests were evaluated with the DYNA2D hydrocode. Three donor (pressed pentolite)/attenuator (PMMA) configurations were tested. Case I and Case 2 had a pentolite donor which was 2 cm × 2 cm right cylinder; the cell size was smaller in Case 1. Case 3 utilized a composite pentolite donor 2.07 cm long but having stepped diameters of one and two cm; the cell size was quite similar to that of Case 2. Peak (axial) pressure versus distance results from Case 1 were scaled and Compared to experimental data for both the NOL large scale gap test (LSGT) and the NSWC expanded large scale gap test (ELSGT). The comparison was found to be very good for the LSGT but less satisfactory for the ELSGT. Peak (axial) pressure versus distance results from Case 1 were the also compared to Case 2, a coarser zoned model similar to Case 1, and Case 3. This comparison showed that the composite donor produced peak (axial) pressures similar to those from the LSGT model. Normalized peak pressure versus radial distance and shock profiles were compared for the three cases and found to be quite similar. Additional normalized peak pressure versus radial distance and normalized pressure versus time information from Case 1 is plotted to show how the pentolite/PMMA rarefaction affects both the axial and radial pressure-time histories.     

Time Resolved Pressure Measurement of the Initiation in Gap Test Experiments

Time resolved measurement of shock pressures in high explosives is possible with inexpensive composite carbon resistors. These resistors are embedded plane to the surface of a Plexiglas slab fixed at the end of the explosive. This configuration was used with gap test experiments with a 10 g donor charge. No initiation delay is measured in Seismoplast I (plastic PETN) up to a gap height of 10 mm PMMA (Plexiglas) due to the time resolution of the measuring system. From 10 mm to 22.5 mm gap height distances for detonation development up to 25 mm are found. For even greater gap heights a shock wave with decreasing amplitude occurs. The detonation development can be explained by the measured structure of the shock waves. Behind a first shock front with nearly constant pressure a second front propagates with increasing pressure which at last catches up with the first and then the pressure increases further up to the Chapman-Jouguet pressure of 160 kbar. At a gap height of 25 mm a stationary shock wave configuration with amplitudes of 20 kbar and 30 kbar was observed.     

Re‐Calibration of the UK Large Scale Gap Test

A new donor explosive, ROWANEX 3601 has been selected for use in the large scale gap test (LSGT). It was necessary to calibrate the peak pressure recorded on the central axis of the PMMA gap using calibrated piezo‐resistive pressure transducers as a function of the gap thickness. The stress history within the PMMA gap was measured and the peak pressure plotted against gap thickness as a calibration. Further effects were noted relating to the curvature of front exiting the donor charge and the validity of the measurement of the transmitted shock at small gap thicknesses.     

Analytical and Numerical Study of the Shock Pressures in the Gap Test

This paper analyzes the functional relationship of pressure induced in the gap versus distance travelled. P = k e^−ax. An analytical shock matching calculation is described to evaluate the constant k as a function of the density and the velocity of detonation of the donor explosive. TDL code is used to check the values of the constants for several donor explosives, and to compute the decay constant a. Functions for pentolite are compared with experimental data from bibliography. The method can be used to predict equivalent gap test thicknesses for donor explosives different from the commonly used pentolite.     

Detonation characteristics of emulsion explosives sensitized by MgH2

Preliminarily results on the reaction mechanism of detonation of composite emulsion explosives sensitized by MgH₂, which simultaneously plays the role of an energetic material, are presented. Compared to emulsion explosives sensitized by glass microspheres, emulsion explosives sensitized by magnesium hydride have a different reaction mechanism of detonation. The shock wave overpressure, specific impulse, shock wave energy, and bubble energy are all greatly increased with the use of MgH₂, and it is noticeable that the shock wave overpressure and shock wave energy increase by 17% and 24%, respectively. In addition, emulsion explosives sensitized by MgH₂ improve significantly in terms of detonation velocity and brisance. These emulsion explosives also meet safety requirements.     

铝粉含量和粒径对乳化炸药作功能力的影响

为研究铝粉对乳化炸药作功能力的影响,在负氧平衡的乳化炸药中分别添加不同含量和粒径的铝粉,采用测时仪法测定其爆速;通过水下爆炸实验计算出含铝乳化炸药的比冲击波能、比气泡能和总能量等参数。结果表明,当铝粉(粒径为5μm和35μm)质量分数为5%时,含铝乳化炸药的爆速最大,分别为5 128、5 071m/s;当铝粉(粒径为5μm和35μm)质量分数为20%时,乳化炸药的比冲击波能、比气泡能、总能量均随着铅粉含量的增加而增大,比冲击波能分别增加19.7%、15.3%;比气泡能分别增加12.6%、13.7%,总能量分别增加15.1%、14.5%。