DNAN 炸药熔铸工艺安全性分析

为确保新型载体炸药DNAN熔铸装药过程的安全性,着重从炸药的基本特性和装药工艺流程等方面对熔铸装药工艺进行安全分析,并采用自行设计的一种烤燃试验装置,对DNAN的热安全性进行试验研究,得到其在不同温度下的热爆炸延滞期。结果表明:DNAN在220℃环境温度下,放置48 h没有发生反应;230℃发生不完全燃烧;当温度达到240℃以上时发生热分解反应;理论计算DNAN在通常的熔药温度(100℃)下的热爆炸延滞期,表明DNAN的装药工艺安全可靠。     

熔铸炸药热爆炸临界工艺温度的计算方法

为评估熔铸炸药装药工艺的热安全性,提出一种热爆炸临界工艺温度的计算方法。以纯DNTF炸药的性能数据,计算不同工艺温度下的热爆炸延滞期,并将其与实际工艺处理时间进行比较,从而确定其热安全水平以及发生热爆炸的临界工艺温度值。计算结果表明：在常规工艺条件下,处理DNTF炸药不会发生热爆炸反应;但随着工艺处理量的增加,发生热爆炸的危险性也会不断增加。该计算方法对于熔铸工艺参数的制定具有重要意义。     

烤燃温度对凝聚炸药热起爆临界温度影响的研究

为了研究凝聚炸药在不同热烤温度下的热分解情况及相应规律,文中采用以RDX为基的高能炸药,以1℃/min的升温速率并采用恒温控制技术,进行了不同温度下的热烤试验,利用FLUENT软件对不同温度下的热爆炸延滞期进行了数值模拟。结果表明,烤燃温度对凝聚炸药的热分解有重要影响,在1℃/min的升温速率条件下,当恒定温度达到178℃后,实验用高能炸药发生自加热反应,最终导致点火;随着炸药装药量的增加,炸药热起爆临界温度在逐渐降低。     

DNAN炸药烤燃特征

熔铸炸药在烤燃过程中会发生炸药熔化,影响炸药热反应过程。本文采用烤燃弹法,对熔铸载体炸药2,4-二硝基苯甲醚(DNAN)进行了烤燃实验,测量了炸药中心温度变化,分析了炸药熔化和反应情况。建立了熔铸炸药热反应计算模型。采用焓-孔隙率方法,计算分析了炸药熔化过程。考虑了炸药自热反应、热传导、熔化后的对流传热和空气的辐射传热。对炸药烤燃实验进行了数值模拟计算。通过与实验结果的比较,验证了计算的正确性。确定了DNAN炸药的活化能和指前因子分别为172 kJ·mol~(-1)和1.20×1011s~(-1)。计算分析了3.3 K·h~(-1)、0.3 K·min~(-1)、1.0 K·min~(-1)、3.0 K·min~(-1)、10 K·min~(-1)和60 K·min~(-1)六种不同加热速率下DNAN炸药的烤燃特征。在慢速烤燃下炸药完全熔化后才点火,而相对快速烤燃下炸药边缘点火,这时炸药内部还未完全熔化。得到了点火时刻的温度分布和液相分数分布。结果表明,在熔铸炸药烤燃中,加热速率对炸药点火前的状态影响很大,从而会影响炸药反应的激烈程度。     

DNAN及TNT基熔铸炸药综合性能比较

为了对比载体炸药2,4,6-三硝基甲苯(TNT)和2,4-二硝基苯甲醚(DNAN)、以及以它们为基的熔铸炸药的综合性能,系统研究了DNAN和TNT、以及DNAN/HMX(20/80)和TNT/HMX(25/75)熔铸炸药的流变、能量、安全、以及力学等性能。结果表明:载体炸药DNAN(6.87 m Pa·s)的粘度低于TNT(9.05 mPa·s),DNAN/HMX熔铸体系的极限固含量(约80%)高于TNT/HMX熔铸体系(约75%);DNAN/HMX(20/80)和TNT/HMX(25/75)熔铸炸药的爆速分别为8336 m·s~(-1)和8452 m·s~(-1),爆压分别为31.03 GPa和31.44 GPa;在1 K·min~(-1)的慢速烤燃条件下,DNAN/HMX(20/80)和TNT/HMX(25/75)熔铸炸药的响应等级分别为燃烧反应和爆炸反应;在4.51GPa的冲击波入射压力条件下,TNT/HMX(25/75)在8～12 mm内达到完全爆轰,而DNAN/HMX(20/80)在12 mm内未能达到完全爆轰;DNAN/HMX(20/80)的抗拉和抗压强度均大于TNT/HMX(25/75)。因此可以得出结论,在能量性能基本持平的情况下,DNAN/HMX(20/80)熔铸炸药的安全及力学性能优于TNT/HMX(25/75)熔铸炸药。     

消焰剂对煤矿许用乳化炸药热稳定性的影响

利用改进的铁板实验测试了NaCl、KCl两种消焰剂对煤矿许用乳化炸药热稳定性的影响。实验结果表明:乳化炸药样品的发火延滞期均随着外界环境温度的增加而减小,最高发火温度随外界环境温度的升高而增加;在相同的环境温度下,含有NaCl的煤矿许用乳化炸药的发火延滞期最长,最高发火温度最高,表观活化能最大,含有KCl的乳化炸药次之,乳化炸药最小。研究表明消焰剂的加入可使得乳化炸药的延滞期延长,最高发火温度和表观活化能增加;在含量相同的情况下,含NaCl的乳化炸药的热稳定性优于含KCl的煤矿许用乳化炸药。     

丙基硝基胍应用基础性能研究

为了获得新型熔铸载体炸药丙基硝基胍的应用基础性能,对其熔铸性能、安全性及特量特性开展实验研究。研究结果表明:丙基硝基胍在高于熔点10℃条件下具有较低的挥发性和良好的熔铸性能,熔融状态的剪切粘度为41m Pa·s,凝固结晶过程与DNAN类似,自发火温度为221.9℃,与常见炸药组分相容,撞击与摩擦感度均为4%,含铝炸药爆轰性能与DNAN基炸药相当。     

含AP的浇铸PBX炸药的热安全性

用自行研制确定火炸药热爆炸临界温度(Tcr)的试验装置测定了直径为10,15,20,30 mm和40 mm,长径比为1∶1的含高氯酸铵(AP)的PBX-A药柱的热爆炸临界温度。用Tcr测定和5 s爆发点试验装置测定了85℃老化70 d前后PBX-A的热爆炸临界温度和5 s爆发点。获得了PBX-A炸药在恒温热刺激下的响应程度,不同直径药柱的热爆炸临界温度,爆炸延滞期(t)与温度(T)的关系以及PBX-A炸药老化前后的热性能变化。结果表明,直径小于40 mm的无约束PBX-A炸药装药在恒温条件下仅发生燃烧。由拟合方程外推直径1 m长径比为1∶1的PBX-A炸药药柱的热爆炸临界温度大于120℃。lnt与1/T只在有限温度范围内呈线性关系。85℃老化70 d前后PBX-A炸药的热爆炸临界温度不变,5 s爆发点降低4.6℃。     

功能助剂对2,4-二硝基苯甲醚基熔铸炸药性能的影响

为了获得适用于2,4-二硝基苯甲醚(DNAN)基熔铸炸药的功能助剂体系,改善其装药性能,通过黏附功确定功能助剂为吐温60和醋酸丁酸纤维素(CAB);采用巴西实验、静态剪切实验、撞击感度爆炸概率法实验、摩擦感度爆炸概率法实验、小隔板实验和液体静力称量法,研究了功能助剂对DNAN 20/奥克托今80(HMX 80)熔铸炸药的拉伸强度、剪切强度、撞击感度、摩擦感度、冲击波感度和装药密度的影响规律。实验结果表明:功能助剂使得DNAN 20/HMX 80熔铸炸药在-40℃、20℃、60℃下的拉伸强度分别增大6.25%、10.3%、47.8%,剪切强度分别增大23.5%、27.8%、45.1%;摩擦感度、撞击感度和冲击波感度分别降低14.29%、4.76%、3.11%;相对密度提高0.2%.因此,功能助剂吐温60和CAB可以用于改善DNAN基熔铸炸药的力学性能和安全性能。     

加速老化对炸药件安全性的影响研究

为了解老化对PBX-6炸药件安全性的影响,分别开展了温度75℃、100 d和65℃、180 d的加速老化试验.对加速老化前后的炸药件,进行了热爆炸试验、火烧试验和跌落试验,对比分析了试验数据,结果表明,老化炸药柱的热爆炸延滞期缩短,热安全性降低;老化炸药件的烤燃时间缩短,烤燃温度降低,爆燃后对炸药外壳的破坏程度更大,热...     

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.     

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.     

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.     

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.     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

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.     

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.     

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.