铝粉粒度和铝氧比对含铝炸药在密闭空间内爆炸特性的影响

为研究铝粉粒度和铝氧比对含铝炸药在密闭空间内爆炸能量输出的影响,对铝氧比为0.45和0.99,铝粉粒度分别为50 nm、5μm和50μm的RDX基含铝炸药进行了内爆炸实验。采用多点平均降噪法对压力曲线进行降噪处理获得准静态压力,指数衰减近似法获得压力衰减系数的实验数据处理方法,提出用准静态压力(p_(QS))、压力上升时间(t_(QS))和压力衰减系数(ω)三个特征量来表征含铝炸药在密闭空间内爆炸的能量输出特性。实验研究结果表明:铝氧比为0.45,含50μm铝粉的p_(QS)比含5μm和含50nm的分别高0.3%和0.7%;相应的t_(QS)分别延长8.6 ms和10.0 ms。铝氧比为0.99,含50μm铝粉的p_(QS)比含5μm和含50 nm铝粉的分别高31.2%和31.9%,相应的t_(QS)分别延长9.3 ms和9.4 ms。铝粉粒度相同时,铝氧比为0.99的p_(QS)大于铝氧比0.45的p_(QS),t_(QS)亦是如此。对于任一铝氧比炸药,ω随铝粉粒度的增加而减少,对于同一铝粉粒度,ω随铝氧比增加而减少。     

真空环境下铝粉粒度与形状对RDX基炸药爆炸场压力和温度的影响

为研究真空环境下铝粉对含铝炸药爆炸场压力和温度的影响规律,利用密闭爆炸罐测量了粒度为4,13,28μm的球状铝粉和130μm的片状铝粉的四种含铝炸药的爆炸场压力和温度。结果表明,铝粉对含铝炸药爆炸场压力的降低显著性的顺序是13μm球状铝粉4μm球状铝粉28μm球状铝粉130μm片状铝粉,铝粉对含铝炸药爆炸场温度的提升作用大小顺序是28μm球状铝粉130μm片状铝粉4μm球状铝粉13μm球状铝粉,显示铝粉对含铝炸药爆炸场压力和温度的影响与铝粉粒度大小不具有相关性。     

"外嵌内包"微结构的奥克托今/铝复合粒子制备及其应用性能

为改善铝粉在炸药爆轰过程中的动力学条件,采用喷雾包覆法制备奥克托今/铝（HMX/Al）复合粒子,并基于该粒子制备含铝炸药,利用扫描电镜、能谱仪和红外光谱分别对HMX/Al复合粒子形貌、表面元素组成以及化学结构进行表征;通过机械感度、爆热、金属驱动和爆炸罐试验,研究HMX/Al复合粒子基含铝炸药的爆炸性能。结果表明：粒径为13 μm、未经酯类物质清洗及无氟橡胶2603（F2603）预包覆的铝粉有利于形成“外嵌内包”的微结构;HMX/Al复合粒子通过非键作用形成复合结构;制备工艺对撞击感度无显著影响,“外嵌内包”微结构可将HMX/Al复合粒子的摩擦感度由88%降低至12%;HMX/Al复合粒子基含铝炸药的爆热、驱动金属飞片的最大速度和后燃最高温度比传统含铝炸药分别提高5.5%、7.3%和6.4%,证明HMX/Al复合粒子可以使铝粉提前参与爆轰反应,提高铝粉反应完全性。     

密闭空间内六硝基六氮杂异伍兹烷基复合炸药能量释放特性

为研究密闭空间内六硝基六氮杂异伍兹烷(CL-20)基复合炸药爆炸能量释放特性,实验测试了药氧比为0.35～1.00炸药样品内爆产生的准静态压力.基于理想气体绝热模型和铝粒子气化燃烧方程,计算分析了不同药氧比样品爆炸的能量释放过程,应用非线性有限元AUTODYN软件模拟了不同药氧比炸药样品密闭空间内爆炸的作用过程.研究结...     

制备梯度结构来提高HMX/Al复合材料的燃烧和压力输出性能（英）

含铝炸药因其高能量密度和压力输出而被广泛应用。为了调控和提高含铝炸药的二次燃烧反应和压力输出,以竹子的微观结构为灵感设计了具有分级结构的HMX/Al径向梯度药柱,使用3D打印技术制备了不同铝含量和不同铝颗粒尺寸的HMX/Al径向梯度结构药柱,研究了Al含量和粒径分布对HMX/Al梯度结构燃烧性能和压力输出的影响。结果表明,当HMX/n-Al（160 nm）径向梯度结构按照从中心层向外层Al的质量分数分别为10%、20%和30%分布时,内层的燃烧反应和火焰传播速度比外层更快;其密闭空间内由于气体释放而获得的压力（2337.61 kPa）高于反向分布的梯度结构药柱。当HMX/Al径向梯度结构按照从中心层向外层Al粒径依次为10 μm-Al,5 μm-Al和n-Al分布时,梯度结构药柱的燃烧过程比较缓慢,可以看到单独铝颗粒的燃烧现象。当中间层为n-Al时,HMX/Al径向梯度结构具有最大的压力输出（1512.65 kPa）,高于均相的HMX/Al药柱;当中间层为10 μm-Al时,获得了具有双重峰的压力输出。     

Al/PTFE/W反应材料的准静态压缩性能与冲击释能特性

为了提高铝/聚四氟乙烯/钨(Al/PTFE/W)氟聚物基反应材料的冲击反应毁伤效能,开展了Al/PTFE/W反应材料的准静态压缩实验。分析了W的含量(0%,30%,65%)、Al颗粒粒径(13,45,75μm)以及PTFE颗粒尺寸(25,160μm)对反应材料的准静态力学性能的影响。用准静态密闭反应容器对反应材料进行了冲击释能测试,测得反应材料在750~1200 m·s~(-1)的冲击反应压力、释能持续时间。分析了Al颗粒粒径及PTFE材料粒径对冲击反应释能特性的影响。结果表明,当W的含量为0,30%和65%时,反应材料的失效强度分别为55.6、64.8和22.8 MPa,W的含量变化对屈服强度的影响不大。Al颗粒的尺寸从75μm减小到13μm时,反应材料的失效强度从64.7 MPa提高到83.1 MPa,提高幅度为28.4%。增大PTFE基体材料的粒径也可有效地提高反应材料的失效强度。反应材料的初始反应压力阈值和释放能量持续时间受材料粒径和准静态压缩力学性能的影响。     

HMX基含硼铝炸药的释能特性和作功能力

如何有效地运用活性金属来提高炸药的爆炸威力和作功能力是设计金属化炸药的关键问题.为探索B/Al复合粉在增爆炸药和温压炸药中的应用,设计并制备了3种HMX基含硼铝炸药.对Φ100 mm×105 mm样品,用空中爆炸试验和水下爆炸试验研究其能量释放特性;用Φ50 mm圆筒试验评价其作功能力,讨论了微米金属粉含量对含硼铝炸药的释能过程和作功能力的影响.结果表明,空爆和水下爆炸中,在HMX的爆轰作用下,铝粉燃烧能够促进硼粉的后燃效应,释放出大量的燃烧热,形成高温高压的膨胀产物,增加空中爆炸火球的持续时间和水下爆炸的总能量.圆筒试验中,在爆轰产物驱动铜管膨胀破裂之前,没有足够的氧和硼反应,未能体现含硼铝炸药中B的燃烧能量优势.当铜管壁膨胀破裂后,空气中的氧可进一步与B/Al复合粉反应释放大量的燃烧热,增强后效作功能力.     

HMX粒度及其级配对塑料粘结炸药冲击波感度和爆炸输出能量的影响

本研究采用 SSGT小隔板试验测定了主体炸药 HMX粒度和粒度级配对塑料粘结炸药冲击波感度和爆炸输出能量的影响 ,研究的 HMX粒度范围为 1～ 1 50 μm,试验的混合炸药密度为 90 %和95.5%的理论密度。初步揭示了主体炸药粒度及粒度级配对混合炸药的冲击波感度和爆炸输出能量的影响。研究结果对传爆药及混合炸药中主体炸药粒度的选取具有重要的参考价值     

带有铝粉反应的含铝炸药状态方程的研究

为了解释不同粒径铝粉的含铝炸药爆炸做功能力,考虑到铝粉的气化反应,结合爆轰产物JWL状态方程,得到了新的含有铝粉反应的含铝炸药状态方程。利用有限元软件的二次开发,将新的状态方程加入LS-DYNA中,模拟了含铝炸药(76%RDX/20%Al/4%wax)爆炸驱动飞片实验。飞片速度曲线的数值模拟结果与实验结果基本一致。结果表明,铝粉的反应速率随着颗粒的减小而增大,不同颗粒度的铝粉反应规律不同。对于5μm和50μm粒径的铝粉,其反应速率先增大后减小,而50 nm粒径的铝粉,反应速率很快达到最大而后减小。新的状态方程能够描述含铝炸药的爆轰特性,由铝粉的气化反应速率方程可计算得出铝粉反应度随时间变化规律,不再需要试验标定。新的状态方程与JWL-Miller状态方程比较,其应用更方便简单。     

舱室密闭空间中爆炸载荷后燃烧效应数值计算研究

为准确分析梯恩梯炸药在密闭空间中的爆炸载荷,在统一设施标准模型和基于能量守恒的简化计算公式基础上,提出了一种计算爆炸产物后燃烧能量的方法。该方法应用到基于有限元分析软件ANSYS/AUTODYN平台的数值模拟中,实现负氧平衡炸药在密闭空间中爆炸过程的数值仿真计算。计算结果与试验测试结果表明：梯恩梯炸药在密闭空间中发生爆炸时,其爆轰产物的后燃烧效应不可忽视;不考虑爆炸产物的后燃烧效应,数值计算得到的准静态压力较试验值低55%以上,50 ms内冲量较试验值低49%以上;将爆轰产物的后燃烧能量计入后,爆炸压力及冲量时程的计算值与试验值吻合较好,为结构受爆炸载荷响应分析提供了准确的输入载荷。     

Expert Systems Aimed at General Design of Projectiles

Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.     

Parameter Identification for the Valve Control Cylinder System of a Hydraulic Manipulator

In mechanical, hydraulic and electronic systems, the determination of system parameters is often challenging because liquid parameters often change significantly, due to variations in working and environmental conditions. Therefore, it is of significant practical importance to identify those parameters through experimental procedures. A systematic approach to identifying parameters in the valve controlling cylinder system of hydraulic manipulators is provided. It first derives the transfer function of the system, and then uses P control of PID control to predict system parameters. The predicted parameters are further validated using PID control. The prediction through simulation using MatLab language is utilized, which agrees well with experimental results.     

Three-dimensional Numerical Simulation of Combustion Field in the Combustion Chamber

In order to study the effect of rotation on the combustion in the underwater vehicle, a two-phase turbulent combustion process is described with Reynolds stress turbulence model, eddy-dissipation turbulent combustion model, P-1 radiation model and particle tracking model of liquid. The flow in the rotating combustion chamber is simulated at two different working speeds, 0 r/min and 1 000 r/min by Fluent software. The temperature, gas velocity, static pressure of wall and fuel concentration are computed and compared. The results show that the combustion in rotating combustor is faster and more effective.     

Software Communication Architecture Implementation and Its Waveform Application

This paper attempts to do a research on the development of software defined radio（SDR） based on software communication architecture（SCA）. Firstly, SCA is studied and a whole reference model of SCA3.0 core framework （CF） is realized; Secondly, an application-specific FM3TR waveform is implemented on the platform of common software based on the reference model; Thirdly, from the point of view of real-time performance and software reuse, tests and validations are made on the above realized CF reference model and FM3TR waveform. As a result, the SCA-compliant SDR has favorable interoperability and software portability and can satisfy the real-time performance requirements which are not too rigorous.     

Dynamic Simulation of the Tank Gun Recoil Response

By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle‘s velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.     

Survey of Controllable Suspension System for Off-road Vehicles

The controllable suspension system can improve the performances of off-road vehicles both on road and cross-country. So far, four controllable suspensions, that is, body height control, active, semi-active and slow-active suspensions, have been developed. For off-road vehicles, the slow-active suspension and the semi-active suspension which have controllable stiffness, damping and body height are more appropriate to use. For many years, some control methodologies for controllable suspension systems have been developed along with the development of modern control theory, and two or more original control methods are integrated as a new control method. Today, for military or civilian off-road vehicles, the R&D of controllable suspension systems is ongoing.     

Finite Element Analysis of Fretting Behavior Between an Engine Cylinder Block and a Main Bearing Cap

The finite element analysis of the fretting behavior between a cylinder block and a main bearing cap is presented. The stresses, relative fretting slip, fretting friction work parameter W and crack initiation location parameter G on the fretting contact surface of the cylinder block are obtained and analyzed. It shows that the fretting fatigue problem of the cylinder block can be quantitatively explained by W or G. The effects of pretightening force, friction factor and material combination of the cylinder block and the main bearing cap are studied. The computational results indicate that the fretting fatigue of the cylinder block can be allayed by increasing the elastic modulus of the cylinder block, but not by changing the other two factors.     

An Efficient Key Agreement Framework to MANET

Protocols for key management are compared and evaluated from the point of view on mobile ad hoe networks （MANET）. The issues of fault-tolerance and efficiency of key distribution protocols for group communications in MANET are addressed. Most key distribution protocols existing today are primarily designed for wlre-line networks. These protocols either fail to work as intended or cannot work at all when they are applied to the demanding environment of MANET. Parameters and performance of different protocols are analyzed, and then a fiat is given out, on which new protocols or existing ones are designed and modified, so that they can be robust, scalable and efficient in MANET.     

A Physical Model of Electromagnetic Force from PEMA Acted on Metal Projectiles

Electromagnetic armor is a new conceptual combat vehicle technology, which improves remarkably the defensive capability and maneuverability of vehicles. The authors present definitely to apply the electromagnetic theory to analyze the electromagnetic armor. Based on electromagnetics, the experienced expression of projectile and the physical model of PEMA （passive electromagnetic armor） are obtained when electric current flows through the system, and a computer sim- ulation is given.     

The Kinematics Analysis of the Hydraulic Mine-clearing Mechanical Manipulator

Through analyzing the kinematics of the hydraulic manipulator operating system, according to the rules for set-ing up the D-H coordinate system, the generalized coordinate of the manipulator system is established. The rotating and moving joints are selected from the mechanism as joint variables. Each generalized transformation matrix of joints is worked out. The kinematics equation at the finger end of the manipulator is calculated. The obverse solution for the manipulator is gained. The geometrical operating parameters and primary technical specification of the manipulator system are simulated through the computer. The simulative result has shown that the manipulator operating system meets the working task requirements. This research provides theoretical basis for optimizing structural parameters of the manipulator operating. So it also is justified the feasibility for mechanical manipulators to be used in the engineering equipment platform of the hydraulic excavator.