固体炸药冲击起爆尺寸效应的数值模拟

固体炸药样品的装药尺寸对其冲击起爆的特性有着比较明显的影响，本文利用非线性有限元方法模拟计算了JO－9159炸药冲击起爆过程，分析了炸药冲击起爆过程的尺寸效应，结果表明，在一定范围内，JO－9159炸药的起爆力阈值随装直径和装药长度的增大而减小。     

JO-9159炸药强爆轰雨贡纽实验及产物的状态方程研究

采用高速扫描相机测量冲击波在JO-9159炸药试样和铝试样中的传播速度,用对比法得到JO-9159炸药强爆轰产物的雨贡纽关系。采用JWL与γ的联合方程描述炸药强爆轰产物的状态,基于实验结果确定了其状态方程的参数值。结果表明,该状态方程的p-V曲线与实验结果吻合较好。用JWL与γ律联合方程可较准确地描述JO-9159炸药强爆轰产物的状态。     

表面吸附对JO-9159炸药力学性能影响的分子动力学模拟

为研究表面吸附对JO-9159炸药力学性能的影响,通过Materials Studio软件构建了JO-9159炸药无定形六组分模型,在COMPASS力场和NPT系综下,对其(0 0 1)、(0 1 0)和(1 0 0)3种晶面的表面吸附进行了周期性分子动力学模拟;基于模型的平衡轨迹对JO-9159炸药的力学性能进行了研究。结果表明,在295K下,吸附后其各向同性增长,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低;随着JO-9159炸药表面吸附气体分子数量的增加,体系的各向异性减小,各向同性增长,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低;在195~395K内,随着温度的升高,表面吸附后JO-9159炸药的各向异性特征降低,各向同性特征增强,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低。     

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。     

JO-9159炸药柱在加速老化条件下表面特性的变化

采用激光共聚焦扫描显微镜、接触角测试仪、显微-红外联机等表面分析技术,对JO-9159炸药柱的表面特性进行了非破坏性分析。在65℃、湿度<40%RH、贮存4个月的加速老化条件下,可得到如下变化趋势:JO-9159炸药柱在加速老化后,氟橡胶在温度的作用下向炸药柱表面发生迁移,表面自由能下降,表面分子结构未发生明显变化。     

聚能射流冲击起爆屏蔽压装PBX炸药的试验研究

为了分析由聚能射流引起的两种典型屏蔽压装PBX炸药的冲击起爆感度,采用某Ф80mm制式破甲弹作为标准射流源,在炸高为150mm的条件下,对不同厚度45~#钢覆盖板屏蔽的PBX-1和PBX-2炸药进行了射流冲击起爆感度试验;采用"兰利法"对覆盖板的厚度进行选取,得到了聚能射流引爆两种典型压装PBX炸药的临界隔板厚度。结果表明,临界爆轰时,PBX-1炸药覆盖板厚度为35～40mm,PBX-2炸药覆盖板厚度为140～150mm,即PBX-1的临界隔板厚度比PBX-2炸药减少73.3%;PBX-1炸药起爆所需的射流能量为185mm~3/μs~2,远高于PBX-2炸药,因此PBX-1炸药的射流安全性显著优于PBX-2炸药。     

非均质固体炸药冲击起爆与爆轰研究进展

综述了非均质固体炸药的冲击起爆机制、宏细观反应流模型、中尺度/跨尺度及连续介质尺度数值模拟和冲击起爆试验及测试技术等研究进展,并总结作者团队近年来在该领域的研究成果;分析了该领域的未来发展趋势,旨在加深对非均质固体炸药冲击起爆爆轰物理机制的认识,为装药安全性研究提供方法和技术手段。指出非均质固体炸药冲击起爆物理响应过程复杂,往往由多种热点机制控制,现有反应速率模型考虑热点机制单一,无法适应冲击起爆过程的高保真计算。现阶段压力相关型反应速率模型虽然在一定范围内适应细观结构的变化,但无法描述复杂加载路径如多次加载和斜波-冲击复合加载下炸药脱敏或敏化、拐角效应死区现象等,而熵或温度相关型反应速率模型可较好地适应复杂加载,但未考虑细观结构响应机制。发展多热点机制耦合作用的、宽适应范围的宏细观反应速率模型是反应流模型的重要方向。快响应高分辨率的细观实验诊断技术一直是爆轰领域的技术难点,中尺度计算是现阶段冲击起爆热点机制研究的主要手段,已初步实现从中尺度到宏观尺度的冲击起爆跨尺度计算,仍是非均质固体炸药冲击起爆与爆轰问题数值模拟发展的重要趋势。附参考文献151篇。     

破片冲击起爆屏蔽B炸药比动能阈值研究

为了研究破片冲击起爆屏蔽B炸药的比动能阈值,采用六棱柱和圆柱钨合金破片冲击带有40Cr炸药盒的B炸药,并测量了B炸药的速度阈值。根据比动能的计算方法,得到破片冲击起爆屏蔽B炸药的比动能阈值范围。运用Autodyn-3D软件和点火增长Lee-Tarver模型,计算了两种破片在垂直侵彻和最大迎风面积两种状态下的比动能阈值,重点研究了最大迎风面积状态下破片冲击起爆屏蔽B炸药的比动能阈值随长径比的变化规律。结果表明,六棱柱破片的比动能阈值低于圆柱破片;随着长径比的增加,破片冲击起爆屏蔽B炸药的比动能阈值先增加后减小。     

炸药粉末压制工艺参数对药柱质量的影响

为了提高炸药粉末的压制成型质量,采用将炸药粉末视为连续体的建模方法,利用Shima-Oyane材料模型,以Φ26mm×22mm的JO-9159炸药药柱为例,采用高级非线性Msc.Marc建立了粉末压制过程仿真模型,分析了不同位置粉末位移及相对密度变化规律,研究了压制速率、初始密度对炸药粉末成型后相对密度及回弹量的影响。结果表明,Shima-Oyane材料模型可以较好地模拟粉末压制成型过程;炸药粉末流动的方向主要为轴向流动,与模具接触区域流动相对缓慢;压制速率以及初始密度影响炸药粉末成型后的质量,初始相对密度的提高有助于提高炸药粉末成型后的质量;压制速率在230~250mm/s时,粉末成型后相对密度较为均匀、回弹量较小,即粉末成型质量较好。     

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。     

PBX炸药细观结构冲击点火的二维数值模拟

为了研究冲击加载下非均质炸药的点火机理,对PBX炸药细观结构在冲击加载下的响应过程进行了二维数值模拟.首先对炸药颗粒的压制过程进行数值模拟,获得PBX炸药的细观结构模型.然后对炸药冲击点火进行数值模拟计算,考虑了热力耦合作用和炸药自热反应,分析了炸药颗粒尺寸、密度和黏结剂对炸药冲击点火的影响.结果表明,冲击作用下PBX...     

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.     

乳化剂含量与乳化炸药压力减敏关系

通过测试水中爆炸冲击波,将乳化炸药压力减敏作用数量化,用减敏程度来表征,定量地比较和分析炸药的抗压性能.采用该方法研究了Span-80含量与乳化炸药压力减敏作用之间的关系.结果表明,乳化剂含量对乳化炸药的压力减敏作用有较大影响,随着Span-80含量的增加,乳化炸药发生压力减敏作用的程度减小,其含量为4％时,减敏程度最小,亦即抗压性能最好,乳化剂含量继续增加炸药的抗压性能下降.     

Effect of Aluminum Fiber Content on the Underwater Explosion Performance of RDX‐based Explosives

In order to analyze the effect of aluminum fiber contents on the underwater explosion performance of RDX‐based explosives, the pressure‐time curves of composite explosives with different aluminum fiber contents are measured by underwater explosion experiments. Peak pressure, impulse, shock energy, and bubble energy were obtained by analyzing the curves. The results show that the peak pressures of composite explosives decrease with increasing aluminum fiber contents. The shock impulse of the 30 % aluminum fiber composite explosive is the highest in all composite explosives. The effects of the 20 % and 40 % composite explosives are nearly equal to that of the 30 % explosive, and the different values of shock impulse among them do not exceed 5 %. The specific shock energy of the 20 % aluminum fiber composite explosive is the highest in all composite explosives. The bubble energy and explosion energy of composite explosives increase with increasing aluminum fiber contents.     

Comparative brisant characteristics of some classes of industrial emulsion explosives

The four types of mixtures consisting of the two bases (aqueous solutions of ammonium nitrate and ammonium dinitroamide) and the two additions (hollow glass microballoons and gunpowder) are considered in this work. On the base of thermodynamic computations of an ideal detonation and accompanying processes (shock and rarefaction waves) there were obtained not only the dependences of detonation parameters on addition quantities to mixtures, but the pressure versus particle velocity diagrams, too, which in comparison with Hugoniots relatively soft (water) and hard (aluminium) substances allowed to determine values of pressure in the shock waves being produced in surroundings nearby the end-wall and lateral surface of a charge. It is proposed to characterize the brisant effect of an explosive by a value of relative brisance which is calculated as percentage ratio of pressures of shock waves generated in surroundings under the same conditions by detonation products of the given explosive and the standard one. It is shown that the brisant effect of the new emulsion explosives is comparable and even can exceed that of TNT of maximal density. It is shown as well that the brisant ability of industrial emulsion explosives can be raised by 60 and more percents by replacing ammonium nitrate with ammonium dinitroamide and hollow glass microballoons with powders being obtained as a result of military industry conversion and utilization of munitions.     

Shock Initiation of Energetic Materials at Different Initial Temperatures (Review)

Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of Manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental Manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 [92.5% triaminotrinitrobenzene (TATB) with 7.5% Kel-F binder] and LX-04 [85% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15% Viton binder] at several initial temperatures. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 6, pp. 181–192, November–December, 2005.     

KCl含量对乳化炸药压力减敏的影响

在相同的乳胶基质中分别添加0%、2%、4%、6%和8%的KCl,再分别用膨胀珍珠岩和化学发泡剂敏化制备2组乳化炸药。测试各乳化炸药水中爆炸冲击波,得出它们未受压和受压后的爆炸冲击波压力峰值,利用波峰值计算乳化炸药的压力减敏度。依据压力减敏度数值,分析KCl含量对乳化炸药压力减敏作用的影响,并测试不同KCl含量下分散相的析晶点,分析不同KCl含量造成压力减敏变化的原因。结果表明:KCl含量在0%～2%之间时,乳化炸药的压力减敏度无明显变化,KCl含量在2%～8%之间时,KCl含量对乳化炸药的压力减敏度有较大影响,而且呈现出正线形相关性。     

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.     

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。