B炸药爆轰波拐角传播的三维数值模拟

为研究B炸药起爆后爆轰波在拐角中的传播特性以及拐角爆轰低压流场现象,运用LS-DYNA3D程序对120°,90°,45°三种特定的拐角装药的爆轰波传播现象进行了数值模拟,观察了爆轰波通过拐角的传播过程,讨论了爆轰波波阵面通过拐角后爆速的变化情况.结果表明,爆轰波通过拐角后由于传播面积的变化而产生衰减-增长过程,装药拐角越大,爆轰波通过时越稳定;随着装药拐角的减小,拐角处的波阵面压力、爆速和传播能力都逐渐降低.     

DNTF基含铝炸药复合装药的驱动特性

设计了内外层分别由含铝质量分数为5%和20%的DNTF基炸药组成的复合装药。采用直径50mm圆筒试验测量了其爆速及圆筒壁的膨胀位移,研究了不同复合装药结构的能量释放特性,并与单一配方装药进行了对比。结果表明,内层为高爆速炸药时,爆速约为两种单一装药的平均值,后期驱动能力没有显著增强,格尼系数仅为2.86mm/μs;外层为高爆速炸药时,爆速略低于高爆速单一装药,爆轰波形具有明显的内聚特征,提高了内层低爆速炸药的能量释放速率,驱动能力持续增强,格尼系数为2.93mm/μs。     

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.     

填充物对单孔双基推进剂爆轰性能的影响

为了提高装药的安全性,以非整体式圆环形双基推进剂为主装药,其间隙分别填充氧化剂混合胶液、空气、沙子、水、木屑、橡胶等,采用电离法和见证板法测定装药的爆轰性能。结果表明,用氧化剂混合胶液与水填充的主装药爆轰速度较大,空气填充的主装药爆轰不完全;得到用氧化剂混合胶液与空气填充时非整体式装药的爆速与装药药段长和空隙尺寸关系的表达式。     

带隔板复合装药结构对双层罩毁伤元成型的影响

针对带隔板复合装药爆轰波控制问题,利用LS-DYNA软件仿真研究了不同隔板参数及复合装药结构参数对爆轰波传播及作用过程的影响;结合X光成像试验验证并通过仿真研究了双层药型罩在不同装药结构参数下的成型规律。结果表明,随着隔板厚度及复合装药高度的增加,复合装药爆轰波由球面波向V形波转化,使得双层药型罩从包覆式侵彻体向杆式侵彻体转换;其中侵彻体的头部速度和长径比与隔板厚度、装药高度、炸药性能呈正相关,与隔板半径、隔板底部距起爆中心位置、内外层炸药直径比呈负相关,当隔板厚度为0.114～0.142倍装药口径、隔板半径为0.400～0.429倍装药口径、隔板底部距起爆中心位置为0.100～0.129倍装药口径、复合装药高度为0.971～1.257倍装药口径、内外层炸药直径比为0.77～0.83时,杆式侵彻体成型较好。     

CL-20基含铝炸药爆轰波阵面法向速度与曲率的关系

采用高速扫描相机及电探针测速法测量了具有相同铝含量的CL-20基和RDX基含铝炸药的拟定态爆轰波形及爆速,分析了炸药波阵面法向速度Dn与曲率κ之间的函数关系。结果表明,CL-20基含铝炸药的爆轰波阵面较RDX基含铝炸药的平坦,其法向爆速受曲率效应的影响也较RDX基含铝炸药的小。当κ0.005mm-1时,其法向爆速的下降速率明显小于RDX基含铝炸药;当κ0.005mm-1时,其法向爆速的下降速率略高于RDX基含铝炸药。     

分散药T型装药控制二次引爆型FAE云雾研究

为了控制新型FAE弹体云雾的窜火、形状、直径与高度等,设计出直径不同的两种药柱间隔装填的分散药T型装药结构,着重对两种药柱的半径、高度、爆速、密度、分散药燃料比进行了设计。在假设小药柱以平面爆轰波引爆大药柱的前提下,对大药柱爆轰波正常传播条件进行了理论推导。选择宏观固态燃料,对Φ330mm×430mm的新型FAE炸弹进行静爆实验;运用柯达高速运动系统观测云雾形成及爆轰过程,并对FAE云雾的直径、高度和体积进行了处理和分析。结果表明,分散药T型装药能有效地控制FAE云雾的形状、直径、高度以及云雾体积,特别是对遏制云雾窜火有很好的效果。     

微/纳米粒度级配对炸药爆轰波阵面D_n(κ)关系的影响

为了研究微/纳米铝粉/RDX粒度级配对含铝炸药爆轰波阵面曲率效应的影响,采用光学波形扫描及电探针测速法测量了不同微/纳米铝粉/RDX粒度级配的含铝炸药在常温环境下的拟定态爆轰波形及爆速,并基于实验结果分析了炸药爆轰波阵面法向速度D_n与当地曲率κ之间的函数关系。结果表明,采用微/纳米铝粉/RDX粒度级配时,波阵面弯曲程度明显变小,且法向爆速受曲率效应的影响减弱,其中,微/纳米RDX颗粒质量比为50∶25或微/纳米铝粉颗粒质量比为15∶5时波形较为平坦,其最大曲率分别约为0.013和0.014mm~(-1),法向爆速较拟定态爆速的最大降幅分别约为0.03和0.04mm/μs,相当于常规微米试样的56%和61%,反映出波阵面能量因侧向流动而发生的损耗较小。     

爆轰波叠加作用下金属杆条断裂行为分析

为了分析爆轰波叠加作用下45~#钢杆的断裂行为,进行了爆轰波叠加效应试验。通过数值模拟分析了杆条受力分布及断裂过程,分析了起爆模式、起爆间距和装药高度对杆条断裂行为的影响,并通过试验对数值模拟结果进行了验证。结果表明,爆轰波叠加后产生一条狭窄的压力增强带,在试验靶板上造成深度为1mm的刻痕;起爆模式影响受力分布的均匀性,起爆点位于传爆药一端时,靠近起爆点一端的杆条所受压力峰值明显低于其他杆条;起爆点位于传爆药中心时,杆条受到爆轰波的作用时间更加集中,且压力大小接近;装药高度与起爆间距的比值在0.75～1.25之间时,爆轰波叠加后作用到杆条的压力随着装药高度或起爆间距的增加而增大。起爆间距对爆轰波叠加压力的影响比起爆点位置和装药高度的影响更明显。     

高速摄影机与计算器联用测定爆速爆压

一、前言炸药的爆轰压力与爆轰波速度的精确测定对于爆轰理论的研究具有重要的意义。为了在测定爆压的同时直接得到同一样品的爆速值,我们探讨了联测法。在原来计数法测爆速的基础上,将高速摄影机与计数器联用,同时测定炸药的爆速与爆压。这将对新炸药的研究有一定的意义。     

Dynamics of the detonation-wave front in solid explosives

The important role of the shape of the front during detonation wave propagation in gas mixtures was substantiated by K. I. Shchelkin during construction of the theory of spinning detonation. Subsequently, a unique relationship between the curvature of the front and detonation wave parameters has been repeatedly confirmed in experiments, including for condensed high explosives (HEs). The existence of this relationship formed the basis of the theory of the dynamics of the detonation front which had been developed by the end of the 20th century. This paper presents the results of a study of detonation front propagation in cylindrical samples of a low-sensitivity HE of different diameters with one-point and plane-wave initiation. A unique relationship between the detonation velocity and the curvature of the detonation wave front has been found. Ordinary differential equations describing two-dimensional steady-state detonation front profiles for HE charges in the form of a plate, a cylinder, and a ring were derived assuming that the detonation velocity depends on the curvature of the front. It was taken into account that the boundary angle between the normal to the front and the HE edge is unique for each combination of HE and liner material. It was found that the same detonation front profile corresponds to several combinations of liner material and the determining size of the charge (plate thickness, radius of the cylinder or the inner radius of the ring). A comparison of experimental front profiles near the edges of HE charges for these combinations provides data on the dependence of detonation velocity on the curvature of the front at low velocities corresponding to shock-induced detonation regimes. Analysis of previously obtained data for detonating ring charges of low-sensitivity HEs shows that as the detonation velocity decreases, the total front curvature tends to a limit of about 0.05 mm⁻¹, i.e., of the order of the inverse critical diameter. The limit of the front curvature allows predicting the critical detonation diameter.     

Detonation Velocity Deficits and Curvature Radius of Mild Detonation Cords

In order to study the detonation velocity deficits of wound mild detonation cords, a physical model and a theoretical mathematical equation for detonation velocity deficits of wound mild detonation cords were established based on the detonation wave’s corner effects and delay time phenomenon by using non‐dimensional analysis method. Besides, a semi‐empirical formula for detonation velocity deficit of wound mild detonation cords in the same charge size was obtained through experiments and curve fitting. Both the theoretical mathematical equation and the semi‐empirical formula show that the detonation velocity deficit of wound mild detonation cords and the reciprocal of the curvature radius have an exponential relationship.     

Detonation velocity deficit and curvature radius of flexible detonation fuses

The detonation velocity deficit in bending flexible detonating fuses is studied, based on the detonation wave’s corner effects and delay time phenomenon. A physical model and a theoretical mathematical equation of the detonation velocity deficit are established by using the dimensional analysis. Based on experimental data, a semi-empirical formula of the detonation velocity deficit for bending fuses in the same charge size is derived. It is shown that the detonation velocity deficit and the reciprocal of the curvature radius are in an exponential relationship.     

基于钽球缺药型罩的多模式毁伤元成型规律

为研究钽球缺药型罩毁伤元成型规律,通过爆轰波碰撞理论和马赫高度计算模型分析了起爆半径对毁伤元成型的马赫超压和马赫高度的影响;利用LS-DYNA有限元程序研究了钽球缺药型罩结构参数(内曲率半径、外曲率半径、罩壁厚)对毁伤元成型的影响。结果表明,中心单点起爆可以形成EFP,环起爆半径为0.8倍装药半径可形成杆式EFP;毁伤元速度和密实度与药型罩内曲率半径呈正相关,与药型罩外曲率半径和药型罩壁厚呈负相关,毁伤元长径比与药型罩内外曲率半径以及壁厚呈负相关;在药型罩内曲率半径R1和外曲率半径R2关系为1.04相似文献   

Studies of Detonation Characteristics of Aluminum Enriched RDX Compositions

Research on the effect of aluminum contents and of its particle size on detonation characteristics of RDX‐based compositions containing 15–60% aluminum was carried out. Measurements of detonation velocity for different charge diameters and confinements were performed. To measure the shock curvature of the detonation wave, X‐ray photography was applied. Unconfined charges and charges confined with a water envelope were tested. The radius of the detonation front curvature was determined. The cylinder test results were the basis for determination of the acceleration ability and energetic characteristics of the detonation products of the mixtures. The Gurney energy describing the acceleration ability was found. The detonation energy of the mixtures tested was also estimated from the cylinder test data.     

Detonation velocity of mechanically activated mixtures of ammonium perchlorate and aluminum

The detonation properties of mechanically activated mixtures of ammonium perchlorate and aluminum were studied. The deflagration-to-detonation transition for low-density charges was investigated. Dependences of the detonation velocity of pressed charges with different types of aluminum on the activation time, density, and diameter of the charges were obtained. For compositions with nanosized aluminum, it is was found that the detonation velocity depends nonmonotonically on the inverse charge diameter and remains almost unchanged in a certain range of charge diameters. It is shown that the joint use of mechanical activation and nanosized components of the composite explosive significantly increases the detonability, reduces the critical diameter, and shifts the maximum of the detonation velocity as a function of density to higher charge densities.     

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。     

装药结构参数对轴向预制破片抛掷速度的影响

为研究柱形装药长径比与装药壳体厚度等结构参数对轴向预制破片抛掷速度的影响规律,以Gurney公式的假设为基础,提出爆轰产物二维运动假设条件,推导并得到轴向预制破片抛掷速度与装药长径比和装药壳体厚度之间的关系式.模拟了柱形带壳装药结构对轴向驱动预制破片抛掷速度的影响,所得结果与文献值吻合.用数值模拟结果修正关系式,得到柱形带壳装药结构参数对轴向预制破片抛掷速度的影响规律,以及轴向预制破片抛掷速度沿径向的分布规律.     

理想混合炸药模型的提出及其应用

通过建立“理想混合炸药”模型 ,发现理想混合炸药的爆速 Did与纯组分炸药的爆速 Di和质量分数 Wi之间存在着定量关系 ,据此发展了一种计算混合炸药爆速的新方法。对大量混合炸药的计算结果表明 ,爆速计算值与实验值的一致性令人满意 ,平均误差 1.37%。本文方法的提出 ,不仅提供了一种预测混合炸药爆速的方法 ,而且对高爆速混合炸药的研究具有一定的指导意义     

人工神经网络法预测炸药爆速的研究

以分子连接性指数作为炸药分子的结构描述符,利用ＢＰ人工神经网络算法,通过对４０种炸药的建立炸药分子结构与爆速之间的定量模型,并对另外１４种炸药进行了爆速预测,结果表明,该模型较好地反映了炸药分子结构与爆速之间的关系,具有较高的预防精度。该方法为新型炸药分子设计时正确估算其爆速提供了一条新的途径。