Blast characteristics and TNT equivalence values for some commercial explosives detonated at ground level

We report measurement of the pressure-time profiles produced by the initiation at ground level of four common commercial sector explosives with different detonation velocities. The results indicate that there are no significant differences in the blast waveshapes from the explosives when measured at distances of 25 and 50 m from the initiation point. Analysis of both peak overpressure and positive phase impulse data has yielded values for the TNT Equivalence of the materials at two scaled distances. Our work indicates that the TNT Equivalence values of the materials studied vary with scaled distance and on whether they are evaluated from overpressure or impulse.     

岩石型乳化炸药的TNT当量

通过２．４ｋｇ、１５ｋｇ、４２ｋｇ量级的ＴＮＴ和岩石型乳化炸药空中爆炸实验，利用曲线拟合法，得出了与实验结果吻合较好的ＴＮＴ，岩石型乳化炸药中爆炸的压力表达式，并求出了压力在１０ｋＰａ￣１０００ｋＰａ时，该乳化炸药的ＴＮＴ当量与对比距离的关系，在这个压力范围内，岩石型乳化炸药的ＴＮＴ当量的平均值是０．７０８。     

不同组分温压炸药的爆炸冲击波特性

为了更好地运用炸药爆炸的毁伤能力,采用相关实验手段对不同组分温压炸药的冲击波超压、正压作用时间及冲量等反应爆炸冲击波特性的参数进行了研究,并将测得的实验结果与TNT的爆炸冲击波特性进行了对比分析。结果表明,两种温压炸药W-1、W-2的爆炸性能均强于TNT炸药,且由于固液混合相温压炸药W-2中各组分混合得更为均匀,其爆炸性能强于固相温压炸药W-1,可为进一步研究温压炸药毁伤效应提供参考。     

径向不耦合装药爆破效果的数值研究

为了研究径向不耦合条件下爆破效果的影响因素,利用AUTODYN-2D对比不耦合系数、不耦合介质、炸药种类对爆破效果的影响规律。结果表明,与耦合装药相比,径向不耦合装药条件下炮孔压力明显降低。对比水介质和空气介质下的爆破效果可知,水介质不耦合条件下,炸药爆炸能量的传递效率更高。炮孔压力与炸药种类密切相关,TNT产生的炮孔压力最大,但作用时间较短,而ANFO和乳化炸药的作用时间较长。     

径向不耦合装药爆破效果的数值研究

为了研究径向不耦合条件下爆破效果的影响因素,利用AUTODYN-2D对比不耦合系数、不耦合介质、炸药种类对爆破效果的影响规律。结果表明,与耦合装药相比,径向不耦合装药条件下炮孔压力明显降低。对比水介质和空气介质下的爆破效果可知,水介质不耦合条件下,炸药爆炸能量的传递效率更高。炮孔压力与炸药种类密切相关,TNT产生的炮孔压力最大,但作用时间较短,而ANFO和乳化炸药的作用时间较长。     

液态CO2相变破岩参数及数值模拟研究

为更好地了解液态CO₂相变破岩技术,对液态CO₂相变的相关参数进行了研究。并通过调节装药不耦合系数,对传统数值模拟方法进行优化,确定了用于施工现场的布孔方式。结果表明:所采用的CO₂相变致裂器的TNT当量为0.29 kg,乳化炸药当量为0.41 kg;其作用于孔壁上的爆轰压力为1 200 MPa,仅为乳化炸药爆轰压力的7.8%;爆容为509 L/kg,约为乳化炸药爆容的50%;破岩范围半径约为1.75 m。提出了用于工程现场的致裂方案,取得了良好的破岩效果。     

Trace detection and discrimination of explosives using electrochemical potentiometric gas sensors

In this article, selective and sensitive detection of trace amounts of pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX) is demonstrated. The screening system is based on a sampling/concentrator front end and electrochemical potentiometric gas sensors as the detector. Preferential hydrocarbon and nitrogen oxide(s) mixed potential sensors based on lanthanum strontium chromite and Pt electrodes with yttria stabilized zirconia (YSZ) solid electrolyte were used to capture the signature of the explosives. Quantitative measurements based on hydrocarbon and nitrogen oxide sensor responses indicated that the detector sensitivity scaled proportionally with the mass of the explosives (1-3 μg). Moreover, the results showed that PETN, TNT, and RDX samples could be discriminated from each other by calculating the ratio of nitrogen oxides to hydrocarbon integrated area under the peak. Further, the use of front-end technology to collect and concentrate the high explosive (HE) vapors make intrinsically low vapor pressure of the HE less of an obstacle for detection while ensuring higher sensitivity levels. In addition, the ability to use multiple sensors each tuned to basic chemical structures (e.g., nitro, amino, peroxide, and hydrocarbon groups) in HE materials will permit the construction of low-cost detector systems for screening a wide spectrum of explosives with lower false positives than present-day technologies.     

不同组分温压炸药的爆炸冲击波特性

为了更好地运用炸药爆炸的毁伤能力,采用相关实验手段对不同组分温压炸药的冲击波超压、正压作用时间及冲量等反应爆炸冲击波特性的参数进行了研究,并将测得的实验结果与TNT的爆炸冲击波特性进行了对比分析。结果表明,两种温压炸药W-1、W-2的爆炸性能均强于TNT炸药,且由于固液混合相温压炸药W-2中各组分混合得更为均匀,其爆炸性能强于固相温压炸药W-1,可为进一步研究温压炸药毁伤效应提供参考。     

Stand-off detection of solid targets with diffuse reflection spectroscopy using a high-power mid-infrared supercontinuum source

We measure the diffuse reflection spectrum of solid samples such as explosives (TNT, RDX, PETN), fertilizers (ammonium nitrate, urea), and paints (automotive and military grade) at a stand-off distance of 5 m using a mid-infrared supercontinuum light source with 3.9 W average output power. The output spectrum extends from 750-4300 nm, and it is generated by nonlinear spectral broadening in a 9 m long fluoride fiber pumped by high peak power pulses from a dual-stage erbium-ytterbium fiber amplifier operating at 1543 nm. The samples are distinguished using unique spectral signatures that are attributed to the molecular vibrations of the constituents. Signal-to-noise ratio (SNR) calculations demonstrate the feasibility of increasing the stand-off distance from 5 to ~150 m, with a corresponding drop in SNR from 28 to 10 dB.     

铵(梯)油类粉状炸药复合油相的研究

文章叙述了岩石粉状硝铵炸药向少梯,无梯炸药发展过程中,所采用的不同材料和配比的复合油相的不断改进,从而生产各种适应于能满足爆破工程需要的铵（梯）油类粉状炸药。     

Detection of explosives and related compounds by low-temperature plasma ambient ionization mass spectrometry

Detection of explosives is important for public safety. A recently developed low-temperature plasma (LTP) probe for desorption and ionization of samples in the ambient environment ( Anal. Chem. 2008 , 80 , 9097 ) is applied in a comprehensive evaluation of analytical performance for rapid detection of 13 explosives and explosives-related compounds. The selected chemicals [pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT), cyclo-1,3,5-trimethylenetrinitramine (RDX), tetryl, cyclo-1,3,5,7-tetramethylenetetranitrate (HMX), hexamethylene triperoxide diamine (HMTD), 2,4-dinitrotoluene, 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,6-dinitrotoluene, and 4-nitrotoluene) were tested at levels in the range 1 pg-10 ng. Most showed remarkable sensitivity in the negative-ion mode, yielding limits of detection in the low picogram range, particularly when analyzed from a glass substrate heated to 120 °C. Ions typically formed from these molecules (M) by LTP include [M + NO(2)](-), [M](-), and [M - NO(2)](-). The LTP-mass spectrometry methodology displayed a linear signal response over three orders of magnitude of analyte amount for the studied explosives. In addition, the effects of synthetic matrices and different types of surfaces were evaluated. The data obtained demonstrate that LTP-MS allows detection of ultratrace amounts of explosives and confirmation of their identity. Tandem mass spectrometry (MS/MS) was used to confirm the presence of selected explosives at low levels; for example, TNT was confirmed at absolute levels as low as 0.6 pg. Linearity and intra- and interday precision were also evaluated, yielding results that demonstrate the potential usefulness and ruggedness of LTP-MS for the detection of explosives of different classes. The use of ion/molecule reactions to form adducts with particular explosives such as RDX and HMX was shown to enhance the selectivity and specificity. This was accomplished by merging the discharge gas with an appropriate reagent headspace vapor (e.g., from a 0.2% trifluoracetic acid solution).     

基于AUTODYN的复合防护结构数值模拟

为了更好地保护小当量爆炸物处理人员的安全,提出了一种由胶体、聚氨酯、泡沫铝和凯夫拉4种材料构成的圆柱形复合防护结构。对100 g TNT爆炸物选择模型比例为1:1,利用AUTODYN软件建立二维仿真模型,采用2D-Euler算法数值模拟此防护结构对爆炸冲击波的减弱效果，并进行分析研究。研究得出:复合防护结构能很好地降低冲击波超压峰值，从而间接地增强人体对超压的忍受度,保证一定范围内人员的生命安全。该防护结构具有便携性、机动性及对爆炸冲击波的高效衰减性,正好适用于轻量、便携及有效防护的应用背景,对相关防护结构的研究设计起到很好的参考作用。     

浅析工艺配方和生产工艺对改性铵油炸药性能的影响

通过对改性铵油炸药的研究,发现由于失去了单质敏化成分TNT的作用,采用不同的工艺配方和生产工艺（设备）制成的铵油炸药性能差别是较大的,从中优选出较为理想的配方和合理的生产工艺设备,从而制造出性能优良的改性铵油炸药,显著地提高爆破使用效果。     

一种新型硝铵炸药敏化剂理论的初步探讨

文中基于2#岩石铵梯炸药梯恩梯敏化理论,对梯恩梯和粉状乳化炸药主要性能指标、形态结构进行对比分析和初步实验认为,粉状乳化炸药可以取代梯恩梯做为工业粉状硝铵炸药新型敏化剂.     

军工炸药边角余料利用的试验研究

军工生产弹类时产生的边角余料和废炸药,过去国内外作销毁处理,造成环境污染和经济损失。文中介绍了军工生产的边角余料TNT/RDX、TNT/Ba(NO_3)_2铸件炸药与NH_4NO_3配制各种民用混合炸药,TNT/RDX的再成型,TNT/Ba(NO_3)_2的分离以及废TNT提纯(分离或提纯后达到民用标准)的试验研究及生产应用。     

TNT detection using multiplexed liquid array displacement immunoassays

The presence of trace contamination of soil and groundwater with explosives is an ongoing concern, for which improved methods are required to facilitate their detection and quantification. This is true both for the monitoring of remediation and for site characterization. Immunosensors have been found effective for solution-phase detection of environmental contaminants. Our work utilized the Luminex100 (flow cytometer) to detect TNT in a multiplexed displacement immunoassay format. The Luminex100 can perform a multiplexed assay by discriminating between up to 100 different bead sets. We used this capability to evaluate four different TNT monoclonal antibodies, two recombinant TNT antibodies, and a control antibody simultaneously for the rapid detection of TNT and other nitroaromatics. TNT could be detected at 0.1 ppb and quantified over the range of 1.0 ppb to 10 ppm. In addition, the assay was shown to be effective in various matrixes such as lake water, seawater, and acetone extracts of soil. Seawater required dilution with two parts buffer to avoid loss of microspheres, while the acetone extracts were diluted 100-fold or more to minimize solvent affects.     

Developments in vapour cloud explosion blast modeling

TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be used as a simple and practical method. Computer codes based on computational fluid dynamics (CFD) like AutoReaGas, developed by TNO and Century Dynamics, could be used also in case a more rigorous analysis is required. Application of the Multi-Energy method requires knowledge of two parameters describing the explosion: a charge size and a charge strength. During the last years, research has led to an improved determination of the charge strength (i.e., the class number or source overpressure) to be chosen to apply the blast charts. A correlation has been derived relating the charge strength to a set of parameters describing the boundary conditions of the flammable cloud and the fuel in the cloud. A simple approach may not be satisfactory in all situations. The overpressure distribution inside a vapour cloud explosion is generally not homogeneous and the presence of obstructions causes directional blast propagation in the near field. A CFD approach, in which the actual situation is modeled, supplies case-specific results. An overview of the key aspects relevant to the application of the Multi-Energy method and CFD modeling is provided. Then the application of the two methods is demonstrated for an example problem involving the calculation of the explosion blast load on a structure at some distance from the explosion in an offshore platform complex.     

接触爆炸下黏土砖砌体墙的抗爆性能

为了研究接触爆炸下黏土砖砌体墙的抗爆性能，采用LS-DYNA有限元软件，以传统单面黏土砖砌体墙为例，建立了黏土砖砌体墙三维分离式细观模型，分析了不同强度接触爆炸载荷下墙体的毁伤和破坏特征。使用两种不同质量的TNT炸药对普通黏土砖墙体在单方向支撑条件下进行了对应的接触爆炸试验验证，并研究其工作机理及响应特性。分析结果表明，随着爆炸载荷的逐渐增加，接触爆炸对墙体的破坏形式主要由中央爆坑以及水平、竖直方向的十字形裂纹的形成，转化为灰缝的层裂、崩落、贯穿以及墙体的错位和倒塌。     

Comparison of visible and near-infrared Raman cross-sections of explosives in solution and in the solid state

Raman cross-sections of explosives in solution and in the solid state have been measured using visible and near-infrared excitation via secondary calibration. These measurements are valuable for both fundamental scientific purposes and applications in the standoff detection of explosives. The explosive compounds RDX, HMX, TNT, 2,4-DNT, 2,6-DNT, and ammonium nitrate were measured using discrete excitation wavelengths ranging from 532 nm to 785 nm. A comparison of the spectral features and cross-sections between the solid state and solution was performed. Comparison is also made to cross-sections measured with deep ultraviolet excitation.     

Desorption electrospray ionization of explosives on surfaces: sensitivity and selectivity enhancement by reactive desorption electrospray ionization

Desorption electrospray ionization (DESI), an ambient mass spectrometry technique, is used for trace detection of the explosives trinitrohexahydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6-trinitrotoluene (TNT), Pentaerythritol tetranitrate (PETN), and their plastic compositions (Composition C-4, Semtex-H, Detasheet) directly from a wide variety of surfaces (metal, plastic, paper, polymer) without sample preparation or pretreatment. Analysis of the explosives is performed under ambient conditions from virtually any surface in very short times (<5 s) including confirmatory tandem mass spectrometry (MS/MS) experiments, while retaining the sensitivity and specificity that mass spectrometry offers. Increased selectivity is obtained both by MS/MS and by performing additional experiments in which additives are included in the spray solvent. These reactive DESI experiments (reactions accompanying desorption) produce such ions as the chloride and trifluoroacetate adducts of RDX and HMX or the Meisenheimer complex of TNT. Desorption atmospheric pressure chemical ionization, a variant of DESI that uses gas-phase ions generated by atmospheric pressure corona discharges of toluene or other organic compounds, provides evidence for a heterogeneous-phase (gaseous ion/absorbed analyte) charge-transfer mechanism of DESI ionization in the case of explosives. Plastic explosives on surfaces were analyzed directly as fingerprints, without sample preparation, to test DESI as a possible method for in situ detection of explosives-contaminated surfaces. DESI also allowed detection of explosives in complex matrixes, including lubricants, household cleaners, vinegar, and diesel fuel. Absolute limits of detection for the neat explosives were subnanogram in all cases and subpicogram in the case of TNT. The DESI response was linear over 3 orders of magnitude for TNT. Quantification of RDX on paper gave a precision (RSD) of 2.3%. Pure water could be used as the spray solution for DESI, and it showed ionization efficiencies for RDX in the negative ion mode similar to that given by methanol/water. DESI represents a simple and rapid way to detect explosives in situ with high sensitivity and specificity and is especially useful when they are present in complex mixtures or in trace amounts on ordinary environmental surfaces.