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爆炸塔设计中常采用等当量集中装药估算爆炸塔内部载荷。为研究该方法的合理性,本文采用有限体积方法离散求解积分型Euler方程组;利用瞬时爆轰模型描述炸药爆炸初场,分别计算了乳化炸药和TNT集中装药爆炸对爆炸塔的内部加载情况;给出了塔体及封头内壁面9个特征点的压力时间曲线。结果表明:可以采用集中装药模拟乳化炸药对爆心截面处的超压作用,但不可以采用集中装药模拟乳化炸药对封头中心处的超压作用。因为在封头中心处乳化炸药爆炸会聚产生的超压极值约为TNT集中装药的2倍;塔体柱段的爆心截面处与封头中心处为超压作用最强的部位,两处冲量大致相当;压力最大值出现在封头中心处,由反射冲击波会聚产生。建议塔体建筑设计时对封头中心处和塔体爆心截面处采取相应的防护措施。 相似文献
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鸟与叶片的撞击过程是一个复杂的加载过程。为了将其简化,以建立一个简单且合理的鸟撞击载荷模型,需要分析鸟撞击载荷的各种因素对叶片响应的影响。本文通过计算机数值模拟进行上述工作。以矩形悬臂板模拟实际叶片,以冲击载荷模拟鸟撞击载荷,采用有限元法计算悬臂板在冲击载荷下的非线性瞬态响应。从鸟撞击载荷的冲量、时间因索、空间因素三个方面分析了冲量、加载持续时间、力-时间函数、初始冲击压力、加载位置、载荷的空间分布以及载荷类型等七种因素对叶片响应的影响。本文得出的结论为合理简化鸟撞击加载过程及建立鸟撞击载荷模型提供了参考与依据。 相似文献
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2~#炸药[重(,,-三硝基乙基-N硝基)乙二胺]是一个零氧平衡的高能炸药。在2~#炸药中混入少量HMX,以氟橡胶粘结,以TATB、石墨和石腊组成的复合钝感剂来钝感,得到了撞击感度和摩擦感度较低的B-01炸药配方。配方组成为2~#炸药/HMX/TATB/氟橡胶/聚苯乙稀/石墨/石腊=70/22/4/2/0.5/0.5/1。 该配方的特点是冲击波感度很高,很容易用2mm直径的柔爆索起爆。其撞击感度与TNT相当(4%),摩擦感度低于14%,爆轰能量相当于PBX-9404,而且容易在低比压下制成不同形状,因此它适用于某些特殊用途的装药。 相似文献
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在采用炸药加载模拟锥壳结构遭受X射线辐照的结构响应实验中,利用激光多普勒测振仪测量了锥壳表面特征点的水平方向速度曲线.并从载荷的侧向余弦分布特点出发,推导了根据锥壳刚体运动的质心水平方向初速计算加载比冲量峰值的公式.同时根据锥壳表面的质点运动特征,提出了截取结构响应基本结束之后的曲线段进行算术平均,通过理论计算修正得到锥壳刚体运动的质心水平方向初速的数据处理方法.最后给出并分析了测量结果,结果表明采用激光多普勒测振仪可以测量炸药加载下结构的刚体运动速度,从而可进一步计算分析结构受到的载荷大小,其精度可以满足工程测量的要求. 相似文献
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温压炸药在野外近地空爆中的冲击波规律 总被引:1,自引:0,他引:1
为了研究温压炸药在敞开空间爆炸中冲击波的规律,选取典型温压炸药制成不同量级的裸药柱进行野外近地空爆实验,同时用TNT进行对比实验,获取温压炸药与TNT的冲击波参数并拟合得到相似律公式。结果表明,温压炸药的冲击波超压峰值在中远场略高于TNT;在相同对比距离处,温压炸药的比冲量明显高于TNT,在对比距离小于2 m/kg1/3的近场,温压炸药的比冲量达到TNT的2倍。引入超压-比冲量曲线描述冲击波特征,表明当超压峰值相同时,温压炸药比冲量更大, 超压峰值在20~50 kPa的中度以下毁伤范围时,温压炸药的比冲量比TNT高40%~60%,可产生更严重的毁伤效应。冲量是爆炸冲击波的重要毁伤元素,应建立与冲量有关的方法评价温压炸药的威力。 相似文献
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薄片炸药可用于模拟强脉冲X射线辐照下空间结构的响应,其与固体靶的冲量耦合作用是进行模拟载荷设计的基础。本文中基于有限元模拟技术,研究不同直径薄片炸药的边界稀疏作用和安装支座的反射作用对薄片炸药与固体靶冲量耦合的影响,结果表明:边界稀疏作用对薄片炸药的比冲量起到减弱的作用,由边界稀疏作用引起的薄片炸药比冲量的变化量和薄片炸药直径的倒数近似成线性关系;薄片炸药安装支座的反射作用对薄片炸药的比冲量起到增强的作用,由支座反射作用引起的薄片炸药比冲量的变化量和薄片炸药直径的平方近似成反比;随着薄片炸药直径的增加,薄片炸药比冲量趋于定值,边界稀疏作用和支座反射作用可以忽略;存在一个临界直径,当薄片炸药的直径为临界直径时,薄片炸药的边界稀疏作用和支座反射作用达到平衡,其比冲量大小和薄片炸药的直径为无穷大时的比冲量值相等。 相似文献
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基于叠加原理,利用炸药接触面起爆方式,实现对可压缩固体材料的矩形波加载. 通过联立爆炸产物和可压缩固体的(u,p)曲线以及综合考虑炸药与材料试件各自由边所受稀疏波干扰情况,从理论上给出冲击波平台压力和冲击波加载平台宽度的计算方法,为将来利用接触爆炸实现对材料试件的近似矩形波加载提供理论基础. 相似文献
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The objective of this research effort was to investigate the quasi-steady flow field produced by explosives in confined facilities.
In this effort we modeled tests in which a high explosive (HE) cylindrical charge was hung in the center of a room and detonated.
The HEs used for the tests were C-4 and AFX 757. While C-4 is just slightly under-oxidized and is typically modeled as an
ideal explosive, AFX 757 includes a significant percentage of aluminum particles, so long-time afterburning and energy release
must be considered. The Lawrence Livermore National Laboratory (LLNL)-produced thermo-chemical equilibrium algorithm, “Cheetah”,
was used to estimate the remaining burnable detonation products. From these remaining species, the afterburning energy was
computed and added to the flow field. Computations of the detonation and afterburn of two HEs in the confined multi-room facility
were performed. The results demonstrate excellent agreement with available experimental data in terms of blast wave time of
arrival, peak shock amplitude, reverberation, and total impulse (and hence, total energy release, via either the detonation
or afterburn processes. 相似文献
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凝聚炸药的短脉冲冲击起爆 总被引:1,自引:1,他引:1
本文介绍了利用电炮研究两种凝聚炸药(TNT/RDX=35/65和PBH-9)的短脉冲冲击起爆的实验结果。炸药样品为直径20mm,长度分别为3.0、5.0、10.0mm的圆柱及楔形药块。在所研究的实验条件下,当药柱长度大于5.0mm时,两种炸药的起爆判据可用p?=常数描述。当药柱长度小于3.0mm时,撞击飞片的阈值速度明显增加。我们还观测了飞片直径对起爆阈值速度的影响,用楔形药块观测了不同加载条件下的到爆轰时间和距离。 相似文献
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CL-20基混合炸药的冲击起爆特征 总被引:1,自引:0,他引:1
为了研究CL-20基混合炸药的冲击起爆特征,深入分析冲击波作用下CL-20基混合炸药的爆轰成长规律,采用炸药驱动飞片冲击起爆实验方法,对CL-20、CL-20/NTO和CL-20/FOX-7三种压装混合炸药进行了冲击起爆实验,通过嵌入在炸药内部不同位置处的锰铜压力传感器,获得了炸药内部压力的变化历程。依据实验结果标定了混合炸药的点火增长模型参数,其中,利用反应速率方程中的两个增长项,分别模拟CL-20/NTO和CL-20/FOX-7混合炸药中两种组分的反应增长过程,得到这两种混合炸药的反应速率方程参数。并通过数值模拟的方法得到了三种炸药的临界起爆阈值和POP关系。研究结果表明:三种CL-20基混合炸药中,CL-20/NTO混合炸药具有更高的临界起爆阈值,而CL-20/FOX-7混合炸药具有更长的爆轰成长距离;此外,利用此套拟合双组分混合炸药反应速率方程的方法,可以对新型配方炸药的冲击起爆过程进行预测性计算 相似文献
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利用光纤探针/光电转换器/示波器技术和楔形炸药块方法,采取电炮驱动薄飞片冲击加载产生高压短脉冲激励的装置,测量了一种以TATB/HMX为基炸药的到爆轰距离,研究了到爆轰距离与初始冲击波压力幅值和脉宽的关系,给出了该炸药的POP曲线和表达式。实验结果有助于了解压力脉宽对钝感炸药的冲击起爆和爆轰成长的影响。对于短脉冲冲击加载,入射压力脉宽对炸药的到爆轰距离影响明显,相同实验条件下,压力脉宽越长,炸药的到爆轰距离越短;相同压力脉宽下,加载压力越高,炸药的到爆轰距离越短。 相似文献
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A transient optical-electrical two-color pyrometer combined with optical-fibers was utilized to measure the temperature of
shock relaxation in air-dusty explosive media in tiny transparent tubes. The external and internal diameters of the tubes
are 3.0 mm and 1.5 mm, respectively. The explosives coated on the inner wall of the tubes are RDX/Al 91/9 with a loading density
of 9 kg/m3 initiated by an electric spark. The temperature profiles versus time at various stages during the ignition-to-detonation
transition processes of the media are given and discussed in detail. It is shown that there is a special temperature structure
of the shock relaxation in multiphase reactive media different from that of a detonation in condensed high explosives.
This article was processed by the author using Springer-Verlage TEX PJour2g macro package version 1. 相似文献
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A new robust numerical methodology is used to investigate the propagation of blast waves from homogeneous explosives. The
gas-phase governing equations are solved using a hybrid solver that combines a higher-order shock capturing scheme with a
low-dissipation central scheme. Explosives of interest include Nitromethane, Trinitrotoluene, and High-Melting Explosive.
The shock overpressure and total impulse are estimated at different radial locations and compared for the different explosives.
An empirical scaling correlation is presented for the shock overpressure, incident positive phase pressure impulse, and total
impulse. The role of hydrodynamic instabilities to the blast effects of explosives is also investigated in three dimensions,
and significant mixing between the detonation products and air is observed. This mixing results in afterburn, which is found
to augment the impulse characteristics of explosives. Furthermore, the impulse characteristics are also observed to be three-dimensional
in the region of the mixing layer. This paper highlights that while some blast features can be successfully predicted from
simple one-dimensional studies, the growth of hydrodynamic instabilities and the impulsive loading of homogeneous explosives
require robust three-dimensional investigation. 相似文献
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V.K. Kredrinskii 《Shock Waves》1997,7(2):63-76
The paper presents a review of the experimental results, mathematical models and numerical investigations of wave processes
and the dynamics of liquid media under impulse loading. The presence of micro-inhomogeneities can change substantially the
state of the liquid, the structure of the applied wave field and the mechanisms of the physical processes that take place
in the liquid. Some crucial research trends received proper attention: the cavitation fracture of liquid under explosive loading,
different methods of describing the mechanisms of pressurized-liquid tank explosions, the effects of bubble cavitation and
inhomogeneities on the sensitivity of high explosives (HE) to the initiation and propagation of detonation, the problem of
focusing the shock waves, and destruction of stones in lithotriptors.
Received 10 August 1995 / Accepted 18 June 1996 相似文献