Interaction of a shaped-charge jet with a target possessing an axial orifice

Interaction of a shaped-charge jet with a target possessing an axial orifice is studied experimentally. For an orifice diameter approximately equal to 0.2D, where D is the shaped-charge diameter, the shaped-charge penetration depth is found to be substantially reduced owing to deviation of the shaped-charge jet axis from the shaped charge axis because of imperfections of the manufacturing technology. A diameter of the target orifice providing unconstrained penetration of the shaped-charge jet is determined. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 13–16, November–December, 2008.     

Effect of initial heating of shaped charge liners on shaped charge pentetration

An increase in the penetration capability of a laboratory shaped charge under initial heating, i.e., heating of the liner material before initiation of the explosive charge, is revealed in experiments. The results obtained confirm the theoretical hypothesis on the possibility of increasing the ultimate elongation of elements of a plastically fractured high-gradient, shaped-charge jet by increasing the initial temperature of the jet-forming layer of the liner. Bauman Moscow State Technical University, Moscow 107005. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 5, pp. 27–31, September–October, 2000.     

聚能射流侵彻径向扩孔的可压缩模型

聚能射流侵彻厚靶时,对靶材同时进行轴向和径向挤压进而发生轴向侵彻和径向扩孔。本文中基于聚能射流侵彻可压缩模型并结合Szendrei-Held扩孔方程,推导给出考虑弹/靶材料可压缩性的聚能射流扩孔方程。为简化完整可压缩模型繁琐的计算过程,又基于Murnaghan状态方程给出可压缩模型的近似解。与水中聚能射流扩孔的实验研究对比分析,表明该模型预测优于Szendrei-Held扩孔方程。模型分析表明,射流半径、驻点压力、靶材强度、驻点处靶材密度以及聚能射流速度是影响聚能射流扩孔的主要因素。本文模型可以更准确地预测聚能射流侵彻可压缩性较强的靶材的扩孔情况。相关工作可为含液密闭结构干扰聚能射流侵彻提供理论基础。     

On the possibility of reducing the penetration capability of shaped-charge jets in a magnetic field

The possibility of reducing the penetration capability of shaped charges by producing a magnetic field ahead of the target with flux lines parallel to the charge axis is considered. The problem is studied on the basis of results of experiments in which a magnetic field was produced in a shaped-charge liner before firing, resulting in a sharp reduction or elimination of penetration. The variation of the magnetic induction in the shaped-charge liner moving in the magnetic field is calculated using the model of two conducting coaxial cylindrical shells corresponding to the charge case and liner and assuming constant induction-current density over the shell thickness. A longitudinal magnetic field is specified on the surface of the outer shell as a function of the spatial distribution of the field ahead of the target and the charge velocity. The magnetic-field intensity that can provide a considerable reduction in the penetration capability of shaped charges of various diameters is estimated. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 3, pp. 112–120, May–June, 2007.     

微声聚能穿孔装置优化设计及IED安全销毁实验

根据Held引爆理论,利用聚能射流使炸药只燃烧或发生不完全爆轰的特点,设计了微声聚能穿孔装置,并对装药结构进行了正交优化.实验结果表明,装置的消声能力良好,用于销毁模拟爆炸药盒时,装药仅发生低速爆轰,达到了安全销毁简易爆炸装置的目的.     

Use of magnetocumulative generators in experiments on current disruption of shaped-charge jets

Results of experiments on disruption of shaped-charge jets by a pulsed current are reported. An industrially produced helical-coaxial magnetocumulative K-80 generator with transformer energy output was used as a source of energy. The operation of the generator in the experiments performed and the effect of the current-pulse parameters on jet disruption and depth of penetration of a shaped-charge jet into a target are discussed. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 3, pp. 30–35, May–June, 1998.     

聚能射流水中侵彻行为的实验研究

对三种不同药型罩形成的射流在水中的侵彻行为进行了实验研究,采用电铜箔测速法及高速摄影法分别获取了聚能射流在水中的行进过程及图像。实验结果表明,水体的边界效应及聚能射流在水中的开坑行为对电铜箔的测量结果影响很大,且聚能射流的准定常侵彻行为在平均速度的变化上表现明显,在准定常侵彻阶段,聚能射流的速度可近似为线性递减,且药型罩构型对射流速度的衰减率影响较大,药型罩材料的影响较小。光测结果给出了聚能射流在水中的运动图像,且据此计算出的射流速度与电测结果吻合较好。     

Rebounding of a shaped-charge jet

The phenomenon of rebounding of a shaped-charge jet from the armour surface with small angles between the jet axis and the target surface is considered. Rebounding angles as a function of jet velocity are obtained in experiments for a copper shaped-charge jet. An engineering calculation technique is developed. The results calculated with the use of this technique are in reasonable agreement with experimental data. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 5, pp. 17–20, September–October, 2007.     

包覆板材料为陶瓷时平板装药的防护性能

运用口径36mm的精密成型装药实验,研究了等效厚度相同的碳化硅和氧化铝陶瓷平板装药的防护性能,并与包覆材料为钢的平板装药进行了对比。运用LS-DYNA3D软件,对平板装药与聚能装药的作用过程进行了三维数值模拟。实验结果显示,对于此结构的平板装药,碳化硅和氧化铝陶瓷平板装药使聚能装药侵彻能力分别下降了88%和82%,优于钢板的防护性能。数值模拟结果显示,陶瓷包覆板从边缘至中心依次出现断裂和粉碎现象,钢板与射流后部作用为断续干扰,而陶瓷板为连续干扰。     

大锥角聚能装药射流形成及对多层靶侵彻的数值模拟研究

运用改进的网格线示踪点法MOCL(MarkOnCellLine)二维多流体欧拉程序 ,对大锥角聚能装药射流的形成及侵彻多层金属靶的全过程进行了数值模拟研究 ,计算结果与试验结果较吻合。这种连贯性的模拟能力避免了数值计算中对射流的许多人为假定。计算和试验结果表明 ,该聚能装药所形成的射流质量约占整个药型罩质量的 32 % ,兼有聚能射流和爆炸成型弹丸的特点 ,更适合于穿透多层大间隔金属靶。     

GPU-accelerated smoothed particle hydrodynamics modeling of jet formation and penetration capability of shaped charges

The prediction of the penetration of three-dimensional (3D) shaped charge into steel plates is a challenging task. In this paper, the smoothed particle hydrodynamics (SPH) method is applied to simulate the jet formation generated by the shaped charge detonation and its damage to steel plates. The Jones–Wilkins–Lee (JWL) equation of state (EOS), Tillotson EOS, and elastic–perfectly plastic constitutive model were incorporated into SPH for the modeling of explosive detonation and dynamic behavior of metal material. The compute unified device architecture (CUDA) parallel programming interface has been employed in SPH to improve the computational efficiency of SPH. Firstly, the constitutive models and EOSs are validated by 3D TNT slab detonation and aluminum–aluminum (Al–Al) high velocity impact. Then the jet formation of the shaped charge detonation and its penetration into the steel plates are investigated using the graphics processing unit (GPU)-accelerated SPH methodology. The numerical results of these test cases are compared against the published experimental data or analytical result, which shows that the GPU-accelerated SPH methodology is capable of tackling the 3D shaped charge detonation and penetration involving millions of particles with high computational efficiency.     

Specific features of interaction of a shaped-charge jet with a target

Coaxial interaction of a copper shaped-charge jet with a thin tungsten rod is considered. A theoretical model of spraying of the shaped-charge jet on the rod and results of experiments performed are presented. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 24–26, September–October, 2008.     

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利用X光照片对射流垂直侵彻反应装甲这一物理过程进行研究，认为爆 轰场加快了射流失稳断裂过程. 并基于射流在空气中运动断裂模型的基础上，运用弹塑性相 关理论，建立了在爆炸场中射流断裂时间模型，利用该模型得到了干扰后射的侵彻模型.     

大气/钢靶板交界处对平行入射聚能射流干扰的数值模拟

利用非线性动力学软件LS-DYNA,对聚能射流平行入射大气/钢靶板交界处的侵彻过程进行了数值模拟.通过分析数值模拟过程和结果,讨论了聚能射流头部速度和碰撞出口处横向速度的变化规律.结果表明:大气/钢靶板交界处不仅降低了聚能射流头部的轴向速度,而且使射流头部产生横向偏移,最大速度达到约1.8 km/s;后续射流横向偏移速...     

Use of shutdown of the capacitive storage in implementing electrical action on metallic shaped-charge jets

Tto improve the efficiency of electrical action on metallic shaped-charge jets, it is proposed to use shutdown of the capacitive storage at the time when the voltage on it during passage of an alternating discharge becomes zero. It has been shown that using this expedient eliminates recharging of the capacitive storage and provides better matching between the current pulse and the time of motion of various parts of the shaped-charge jet through the electrode gap. Studies have been conducted using a computational procedure in which the development of magnetohydrodynamic instability of the jet and the dispersion of its material are considered possible physical mechanisms reducing the penetration capability of shaped-charge jets under the action of high current pulses.     

Experimental investigation of fast shaped-charge jets

The effect of various methods for producing a fast shaped-charge jet on the jet velocity is studied. Experimental results allow one to optimize the process of formation of fast shapedcharge jets. Spectra of a copper jet are obtained, and its temperature is determined. It is shown that fast copper shaped-charge jets can be used for quasi-cw lasing. Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 5, pp. 62–67, September–October, 2000.     

Thermal softening of metallic shaped-charge jets formed by the collapse of shaped-charge liners in the presence of a magnetic field

This paper presents an analysis of the possibility of increasing the ultimate stretching and penetration capability of metallic shaped-charge jets in the presence of an axial magnetic field in the shaped-charge liner due to heating and thermal softening of the jet material as a result of a sharp increase in the magnetic-field induction in the jet formation region upon liner collapse. This process is studied by numerical simulation in a quasi-two-dimensional formulation taking into account the inertial stretching of the conductive rigid-plastic rod in the presence of a longitudinal magnetic field in it.     

线型聚能装药的理论研究

本文提出了一端起爆的线型聚能装药射流形成的不定常理论模型。根据这一模型,当金属罩在爆轰波作用下的运动速度为已知时,则不论此速度是否是时间或初始位置的函数,都能得到射流形成时的速度,质量和位置等参数。 按照本文模型,Defourneaux.M.的定常射流形成定常模型是一个简单的特例。我们利用本文的模型对等厚度装药的情况进行了计算,并与实验结果比较,两者符合良好。同时计算结果表明,考虑射流形成的不定常因素,可以较好地解释射流头部的质量堆积和射流内部的反向速度梯度等实验现象。本文的模型可以为线型聚能切割索的设计提供较为准确的理论指导。     

射流对工业炸药的引爆及侵彻机制

本文用脉冲X光摄影技术及电探极-记录仪系统,对射流引爆及侵彻工业炸药的过程进行了观测,探讨了的流引爆及侵彻工业炸药的机制,给出了射流与工业炸药作用过程的物理图象。     

Meshfree particle simulation of the detonation process for high explosives in shaped charge unlined cavity configurations

The numerical simulation of the detonation of a high explosive (HE) is generally not an easy task for traditional grid based methods. Smoothed particle hydrodynamics (SPH) method, as a meshfree, Lagrangian and particle method, provides a very attractive approach in dealing with large deformations and large inhomogeneities in the extremely transient high explosive detonation and later expansion process. This paper presents the application of SPH to simulate and analyze the detonation process of high explosive in shaped charge. A three-dimensional SPH code is developed and applied to simulate the shaped charge detonation process in different scenarios. It is observed that for high explosive in a shaped charge, the detonation produced gaseous products experience strong convergence that forms an extremely high-pressure gas jet. Factors such as different charge cavity shapes and different detonation models lead to quite different behavior of the gas jet convergence and later divergence. Further analyses reveal that a critical value for the charge head length exists. Beyond this critical value, increasing the charge head length will not result in improvement on the gas jet convergence performance.Received: 11 March 2002, Accepted: 9 December 2002, Published online: 28 April 2003