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。     

聚黑-14C的传爆装置冲击起爆实验及数值模拟

基于聚黑(JH)-14C传爆药的小隔板试验方法及结果,建立了小隔板试验有限元模型并进行了模拟计算,确定了密度为1.65g/cm~3时JH-14C的Lee-Tarver参数。以RDX-8701为主发药柱,对实际装药条件下JH-14C的传爆装置进行了冲击起爆实验,得到了钢鉴定块的凹坑深度。根据小隔板试验确定的JH-14C传爆药Lee-Tarver参数,建立了全尺寸的冲击起爆实验有限元模型,并对比分析了模拟结果与实验结果,通过改变导爆药柱顶部的钢隔板厚度,确定了JH-14C的传爆装置发生冲击起爆的临界钢隔板厚度。结果表明,冲击起爆实验中钢鉴定块的凹坑深度约为2.1mm,模拟计算结果与实验结果基本吻合;JH-14C的传爆装置冲击起爆的临界钢隔板厚度在4~5mm。     

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.     

Shock Initiation of Sheet Explosive

The shock sensitivity of a typical sheet explosive RDX-WAX (90:10) has been experimentally determined with gap test arrangement by measuring free surface velocity in different thicknesses of the barrier and shock and particle velocity of non-reactive shock wave in the sheet explosive with Pin Oscillography Technique. It has been found that a shock wave, generated by a point-initiated cylindrical explosive in contact with an aluminium barrier of diameter nearly twice the diameter of the charge, attenuates exponentially and a 6.5 mm thick sheet explosive, of density 1.28 g/cm³ and velocity of detonation 6.43 mm/μs, detonates with 50% probability by a shock wave of 11 kbar pressure in the explosive.     

薄环形装药起爆技术研究

设计和压制了一种薄型起爆药片及环形药柱,并对其隔爆和起爆能力、可靠性和同步性进行了测试研究。采用环形装药起爆可以有效地提高聚能装药的威力,而且其威力随着环形装药直径的增加而增加。研究结果对于传爆序列的可靠性和起爆技术的研究有重要的参考价值,可用于聚能装药的起爆,提高其作战能力。     

Initiation Tests

In detail, a test method is described which gives the delay times and build up distances of the initiation of squeeze cast or plastic bonded high explosive charges. A special test setup arrangement is used to observe the incoming detonation wave of a high explosive train as the donor or initiating charge and then the breakthrough of the detonation wave at the acceptor charge in the axial direction and in the 90° direction. This allows to define the shift of the detonation breakthrough in the longitudinal direction, and the corner turning distance in the transverse direction and the build up distances in both observed directions.     

Shaped Charge Jet Initiation on Explosive Charges equipped with barriers made up of various materials

This paper describes initiation tests on cast TNT/RDX (35/65) explosive charges applying shaped charge jets with test set-ups on which the HE charge was arranged either in contact to a 50-mm thick barrier or after a 100-mm thick barrier in a 15-mm air gap. A variety of materials was attached to the barrier's rear side which, on one band, resulted in a varying shock wave attenuation and also in different bulging effects that are responsible for the differences in the initiation mechanisms observed on the two test arrangements. Materials with a lower density also provide, due to a less precompression of the IIM charge used on the arrangement “test charge in contact”, shorter buildup distances than materials with a higher density. An exception to this is a high ductile material such as e.g. steel. The build-up distances, however, remain constant when arranging the explosive charge with an air gap. This backs up the hypothesis that most of all, bulging of the target is responsible for the sensitivity reduction observed on the test HE charges in contact with the barrier.     

Energy release of mixed explosives during propagation of a nonideal detonation under conditions similar to the operation conditions of a blasthole charge

Detonation experiments were performed in a specially developed explosive device simulating a blasthole using charges of fine-grained and coarse-grained (granular) 30/70 TNT/ammonium nitrate mixtures of identical density 0.89 g/cm³ in steel shells with an inner diameter of 28 mm and a wall thickness of 3 mm at detonation velocities of 4.13 and 2.13 km/sec, respectively. Despite significant differences in detonation velocity (pressure), identical expansion of the charge shells was observed. On the other hand, numerical simulations of detonation propagation in the explosive device with the corresponding velocities ignoring the possibility of energy release behind the shock front show that the expansion of the charge shell is always greater in the case of a high-velocity regime. It is concluded that under the conditions simulating detonation propagation and the work of explosion products in a blasthole, effective additional energy release occurs behind the low-velocity (nonideal) detonation front. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 4, pp. 111–120, July–August, 2007.     

Evaluation of the James Initiation Criterion in the 21 mm and 50 mm PMMA Gap Test

The gap test has been used for several decades as a measure for the shock sensitivity of high explosives. Normally the axial pressure in the gap is used as the necessary initiation pressure of a high explosive for a shock to detonation transition. But it has been shown in the past that the pressure in the gap is not a suitable measure for shock sensitivity and other criteria like the James criterion in terms of critical energy fluence and critical specific kinetic energy should be used. To evaluate the James criterion in the 21 mm and 50 mm polymethylmethacrylate (PMMA) gap test numerical simulations are conducted. To validate the simulations a 21 mm water gap test is simulated and compared to experimental results, where the axial pressure calibration can be reproduced with high accuracy. With the results from the simulation of the 21 mm and 50 mm gap test it is shown that at the same maximum axial pressure the energy fluence is higher in the 50 mm gap test. This explains to some extent the higher initiation pressures observed in smaller gap tests. The James criterion is derived and it is shown that the two gap tests probe very different regions in the energy fluence vs. specific kinetic energy plane. The results can be used as a calibration for the gap tests and are intended to improve the comparability of gap test results among each other and with different initiation experiments like flyer or heavy fragment impact testing.     

Spin wave and attenuation of liquid explosive detonation

The detonation of nitromethane and a dinitrotoluene solution in bistrinitroxyethylnitramine when the diameter of the cylindrical charge is close to the critical was investigated with the aid of high-speed photography of the luminosity of the lateral and end cylinder surfaces and the recording of the spin wave surface using sampling plates with an air gap. It was discovered that the appearance of penetrating spinning absence-of-reaction waves, which are responsible for the attenuation of liquid explosive detonation, is closely related to the spread of detonation spin waves over the charge surface (or immediately below it). The spin waves, which are instrumental in the propagation of a normal detonation in weakly heterogeneous cast charges consisting of trotyl-hexogene and trotyl-PETN, in the case of liquid explosives probably inhibit the detonation process by inducing the formation of penetrating absence-of-reaction spin waves. It is shown that the spin wave velocity corresponds to the degree of material compression in the near-surface layer, as calculated according to the Dremin-Trofimov model (it can be only slightly above it.)Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 2, pp. 93–98, March–April, 1992.     

Relation between the critical detonation diameter of explosive charges with characteristics of their shock-wave sensitivity

Correlation dependences between the critical diameter of high explosive (HE) charges and characteristics of their shock-wave sensitivity are theoretically justified. Relations for the critical radius of curvature of the detonation-wave front and for the critical detonation diameter are derived on the basis of the author’s theory of the critical diameter and the generalized kinetic characteristic of HE decomposition determined from the experimental dependence of the distance of transition of the initiating shock wave to the detonation wave on the wave amplitude. A qualitative analysis of these relations reveals good agreement with available experimental data. Key words: detonation, critical diameter, sensitivity, shock-wave initiation of detonation, HE decomposition kinetics. __________ Translated from Fizika Goreniya i Vzryva, Vol. 45, No. 3, pp. 101–105, May–June, 2009.     

Calculation of the critical detonation diameter of explosive charges using data on their shock-wave initiation

This paper deals with the further development of the quantitative theory of critical detonation diameter that was earlier proposed by the author. According to this theory, to calculate the critical diameter, it is necessary to know the shock adiabat, detonation velocity, and the generalized kinetic characteristic of decomposition of a high-explosive (HE) charge under shock-wave compression. It is suggested that the generalized kinetic characteristic of decomposition of a HE can be found from an experimental dependence of the shock-wave amplitude on the distance the shock wave travels during shock-wave initiation of the HE charge. This approach allows one to calculate the critical detonation diameters of HE charges with sufficient accuracy. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 2, pp. 112–115, March–April, 2006.     

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.     

固支矩形钢板近距爆炸的毁伤特性

为掌握金属平板结构在近距爆炸载荷下的毁伤特性,以四边固支矩形钢板为对象,开展了柱形TNT装药近距爆炸毁伤试验,根据试验结果划分了钢板的3种毁伤模式:塑性大变形毁伤、临界起裂毁伤和花瓣状破口毁伤,建立了不同毁伤模式下的理论计算和数值模型,并分析了药量、爆距及钢板厚度对其近距爆炸毁伤特性的影响。结果表明,钢板的塑性最大变形随装药质量增加而增加,随爆距增加而减小;钢板的临界起裂毁伤形式为平行于长边的Ⅰ字形裂纹;爆距保持不变时,钢板的最大破口毁伤直径与药量为正相关,2000g药量时的最大破口直径为1000g药量时的1.18倍;相同药量时,随着爆距的增加,钢板最大破口直径呈先增大后减小的趋势,药量为500g和1000g时,最佳毁伤爆距分别为4cm和5cm。     

Air Gaps,Size Effect,and Corner‐Turning in Ambient LX‐17

Various measurements under ambient conditions are presented for LX‐17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner‐turning has been measured with an LX‐07 booster, and the dead‐zone results are comparable to the previous TATB‐boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel‐backed samples are faster than the Lucite‐backed samples by 0.6 μs. Bare LX‐07 and LX‐17 charges of 12.7 mm radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX‐07 booster crossed a 10 mm gap with a slight time delay. Steady‐state LX‐17 crossed a 3.5 mm gap but failed to cross a 4.0 mm gap. LX‐17 charge with a 12.7 mm radius run after the booster crossed a 1.5 mm gap but failed to cross a 2.5 mm gap. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in reactive flow JWL++and Linked Cheetah V4, mostly at 4 zones mm⁻¹. Tarantula has four pressure regions: off, initiation, failure, and detonation. The physical basis of the input parameters is considered.     

Initiation Pressure Thresholds from Three Sources

Pressure thresholds are minimum pressures needed to start explosive initiation that ends in detonation. We obtain pressure thresholds from three sources. Run‐to‐detonation times are the poorest source but the fitting of a function gives rough results. Flyer‐induced initiation gives the best results because the initial conditions are the best known. However, very thick flyers are needed to give the lowest, asymptotic pressure thresholds used in modern models and this kind of data is rarely available. Gap test data are in much larger supply but the various test sizes and materials are confusing. We find that explosive pressures are almost the same if the distance in the gap test spacers are in units of donor explosive radius. Calculated half‐width time pulses in the spacers may be used to create a pressure‐time curve similar to that of the flyers. The very‐large Eglin gap tests give asymptotic thresholds comparable to extrapolated flyer results. The three sources are assembled into a much‐expanded set of near‐asymptotic pressure thresholds. These thresholds vary greatly with density: for TATB/LX‐17/PBX 9502, we find values of 4.9 and 8.7 GPa at 1.80 and 1.90 g/cm³, respectively.     

含废弃丁羟推进剂的凝胶炸药

为安全处理和再利用废弃固体推进剂,通过添加单基药将丁羟推进剂再利用制备了灌注式凝胶炸药.采用验证板试验及电离探针法研究了不同装药配比、推进剂颗粒尺寸及装药直径对炸药爆轰性能的影响.结果表明,丁羟推进剂难以发生爆轰,若添加适量单基药,能显著提高炸药的爆轰感度,并降低其临界直径;该凝胶炸药密度为1.6 g/cm3,直径为7...     

可变形战斗部主辅装药殉爆研究

为确定主辅装药的选型原则，对主装药在两种辅装药滑移爆轰作用下的动态响应过程进行了数值仿真研究，着重考察了辅装药爆轰性能和主辅装药间的隔爆层对冲击波衰减的影响，并结合非均质炸药的冲击起爆临界能量判据，得到传人主装药内的脉冲压力和脉冲持续时间。结果表明，引起主装药殉爆的主要因素是主装药的爆轰感度和辅装药的爆轰压力，隔爆层位置应位于辅装药和外壳体之间。     

A Miniature Device for Shock Initiation of Hexanitrostilbene by High‐Speed Flyer

A miniature device for shock initiation of the hexanitrostilbene (HNS) through micro‐charge detonation‐driven flyer was fabricated. This device consisted of the substrate, micro‐charge, flyer, and barrel. Four types of flyer (titanium of 28 μm, aluminum of 22 μm, copper of 22 μm and polyimide (PI) of 55 μm in thickness) were studied and the effect of micro‐charge thickness, diameter, and barrel length were investigated by measuring the average flyer velocities using polyvinylidene fluoride (PVDF) films. The results show that the titanium flyer is more proper for such initiation device compared to aluminum, copper, and polyimide flyer. The average velocity of the flyer increased with the thickness of micro‐charge and the increment was larger when the thickness increases from 0.3 mm to 0.4 mm than when the thickness increases from 0.4 mm to 0.6 mm. The flyer velocity significantly increased with the increase in the diameter of micro‐charge until a plateau appeared at 0.8 mm. The flyer velocity increased first and then decreased sharply with the increase in barrel length. The average velocity for a 28 μm thick titanium flyer was measured to be as high as 2468 m s⁻¹ when the thickness, micro‐charge diameter and the length of barrel were 0.6 mm, 0.8 mm and 659 μm, respectively. The HNS‐IV explosive with density 1.57 g cm⁻³ was initiated by this miniature device.     

压装工艺对CL-20基炸药性能及聚能破甲威力的影响

利用常温成型和热压成型两种工艺制备了典型的CL-20基混合炸药装药,测试了其装药密度、密度均匀性、力学性能、爆速,计算了格尼系数。对Φ50mm标准聚能装药进行了破甲试验。验证了不同压装工艺条件下装填CL-20基炸药装药聚能射流对45号钢靶的侵彻深度和穿孔直径效果。结果表明,与常温成型CL-20基装药相比,热压成型工艺条件时装药的密度提高不小于1.46%,密度均匀性、爆速和格尼系数和破甲能力试验数据均有不同程度的提高,且Φ50mm标准聚能射流对45号钢靶的平均穿深从310mm提高至343mm,平均穿孔直径由18.0mm增至23.5mm。