强约束固体炸药燃烧裂纹网络反应演化模型

为表征受约束装药非冲击点火后的反应演化行为,建立了燃烧裂纹网络反应演化理论模型。该模型量化了反应烈度,通过与实验结果对比验证了模型的适应性。结果表明：壳体约束越强,高温产物气体自增强燃烧越迅速,装药反应越剧烈,壳体破坏时装药反应度越大;装药结构尺寸越大,炸药反应初期高温产物气体流动和表面燃烧导致裂纹增压扩展过程的时间越长,但后期反应越剧烈,壳体破坏时装药反应度越大;点火阈值压力对装药最终的反应烈度影响不明显。炸药燃烧裂纹网络反应演化模型可较好地反映炸药本征燃烧速率、约束强度、装药结构尺寸等对反应演化的影响规律,为弹药在意外刺激下的安全性设计和烈度量化评估提供了理论基础。     

炸药装药爆炸反应演化过程和约束影响的数值模拟

为分析弱刺激条件下炸药装药反应演化问题和约束条件对炸药爆炸反应的影响,构建了炸药爆炸反应速率增长的唯像模型,采用多介质任意拉式欧拉和流固耦合算法,实现了约束装药局部点火后缓慢燃烧反应到剧烈爆炸反应增长及其与壳体相互作用的数值模拟.基于强约束球形装药中心点火实验,数值模拟分析了约束条件对压装PBX-2炸药爆炸反应压力增长过程的影响,结果表明壳体强度或厚度增加,装药内反应压力的峰值也增大;随着钢壳厚度从5 mm增加到20 mm,压力峰值从163 MPa增大到1357 MPa,而且压力增长过程存在很大的差异,但随着壳体破裂解体,抑制了爆炸向爆轰反应的转变.     

不同机械约束下压装PBX炸药反应演化行为

为研究机械约束下炸药反应演化行为,加深对武器装药意外点火后反应烈度演化影响因素及机制的认识,对压装PBX炸药反应演化过程进行实验研究。设计一种机械约束装药点火实验装置,采用激光干涉仪和压力传感器分别测量壳体膨胀速度和内部压力,分析不同约束下两种HMX基压装PBX炸药装药的反应演化行为;结合空气冲击波超压测试结果和装置、炸药残骸回收分析,表征装药的反应烈度。研究结果表明：2 MPa机械约束下,PBX-1和PBX-2装药反应最高压力不超过200 MPa,壳体膨胀速度在70 m/s左右,装药反应烈度为爆燃;50 MPa机械约束下,PBX-1和PBX-2装药在百微秒甚至几十微秒内压力超过1 GPa,壳体膨胀速度达到500 m/s,装药发生爆炸反应;不同炸药的力学性能会造成装药反应演化过程存在一定差异,但机械约束影响更明显,新装置2 MPa和50 MPa机械约束装药反应压力和约束壳体速度相差接近1个数量级。     

约束HMX基PBX炸药裂缝中燃烧演化实验

为了研究约束装药裂缝中的燃烧演化规律,获取典型尺寸裂缝中的对流燃烧特性,加深对意外事故条件下武器装药发生点火后转变为高烈度反应过程的机理性认识,采用热点火方式结合高速摄影、压力测量等测试技术,对约束条件下某奥克托今（HMX）基高聚物粘结炸药（PBX）（HMX质量分数为95%）不同宽度预置裂缝（50,100,200 μm）中燃烧演化过程开展了实验研究。结果表明,约束装药内部50 μm宽裂缝中的对流燃烧能够产生超过250 MPa的压力,燃烧波阵面传播速度超过400 m·s^-1;裂缝越宽,对流燃烧产生的峰值压力越低,燃烧波阵面传播速度越快;炸药裂缝中的对流燃烧演化主要包含4个阶段：较低压力梯度下点火药燃烧产物的早期对流传播（炸药表面未反应）;产物气体的稳定对流传播伴随炸药表面燃烧导致的裂缝增压过程;炸药大量燃烧导致急速增压伴随约束壳体变形和炸药破裂;极端高压下约束壳体的解体泄压过程。     

HMX基含铝炸药装药慢烤缓释结构设计及验证

为了探索可满足战斗部装药慢烤泄压缓释要求的密封结构设计方法,设计了可调整连接强度及预制泄压孔面积的小型烤燃弹,通过实验获得了奥克托今(HMX)基含铝炸药装药不发生比燃烧更剧烈反应的条件,包括烤燃弹壳体强度阈值、泄压通道面积阈值等参数。据此提出了既能满足端盖具有较高连接强度又能可靠泄压的两级密封缓释结构设计方法,并在具有公斤级装药的烤燃弹中进行了试验验证。结果表明,烤燃弹采用两级密封设计时,若泄压通道与装药截面的面积比不小于30%,且慢烤过程中,气体产物的压力未达到96.5 MPa时便可打通泄压通道,避免了装药反应的进一步增长,使其仅发生燃烧,并保持壳体结构的完整性。     

初始自由空腔体积对PBX-3炸药慢烤反应烈度的影响

为了认识初始自由空腔对约束奥克托今（HMX）基PBX-3炸药慢烤反应烈度的影响，以圣地亚热点火（SITI）实验装置为参考，设计了初始自由空腔体积率分别为1.0%和7.4%的弱约束慢烤实验装置。在相同的温升速率下开展了约束HMX基PBX-3炸药慢烤实验，通过小尺寸K型热电偶测量炸药中心平面不同位置以及壳体表面的温度变化历程，采用耐高温光子多普勒测速探头测量炸药热爆炸后壳体的运动速度，并在慢烤箱中回收实验装置残骸。结果表明：在相同的壳体约束强度和加温条件下，2种不同初始自由空腔体积率的约束PBX-3炸药均在中心区域首先发生点火反应；初始自由空腔体积率为1.0%时，热爆炸时刻壳体表面的温度更高，炸药整体温度更高，炸药点火反应后壳体加速更快、速度更高，实验装置残骸碎片更小，反应烈度更高。分析认为：初始自由空腔体积率为1.0%时，热爆炸前炸药受到的应力更大，炸药损伤更严重；炸药中心点火反应后，更大的热应力使得炸药点火反应产生的气体在中心聚集形成更高的压力，炸药燃烧速率更大，燃烧产生的高温气体更容易进入微裂纹，形成更强的对流燃烧，导致压力增长速率更快，炸药反应更剧烈。     

炸药燃烧产物驱动裂纹动态扩展耦合特性

为了研究炸药燃烧产物驱动基体中裂纹动态扩展的耦合特性,加深对武器装药意外点火后反应进入裂纹形成对流燃烧引发高烈度反应的机理性认识,采用热点火方式对某奥克托今(HMX)基(质量分数为95%)高聚物粘结炸药PBX预置缺口点火,采用数字高速摄影技术对炸药燃烧产物驱动裂纹动态扩展过程开展了实验研究。结果表明,由于高聚物粘结炸药(PBX)存在较强的细观非均匀性,同一种炸药的不同样品细观结构也不完全相同,导致其裂纹扩展路径存在差异(可能沿直线传播,也可能会发生偏转),但是在相同的约束条件和预应力下其扩展速度基本一致,本研究实验条件下,该PBX炸药裂纹扩展平均速度为146.7 m·s~(-1)。     

非 TNT 基高固含量熔铸炸药致密成型工艺研究

为提高炸药的高能量和安全性能,对非 TNT 基高固含量熔铸炸药致密成型工艺进行研究。运用 ANSYS 软件建立熔铸炸药自然冷却温度场,构建装药壳体实体和有限元模型,对装药疵病的产生与防止进行分析。根据“组 分体积形状尺寸匹配准则”,运用振动、抽真空、保温冷却等工艺措施,实现高固含量熔铸炸药高致密成型。研究 结果表明：该工艺使装药内部致密均匀,无气孔、缩孔、裂纹等疵病,可实现高固含量熔铸炸药高致密成型。     

PBX炸药冲击起爆的改进细观反应速率模型

为了系统研究载荷和炸药细观结构对高聚物粘结炸药(Polymer Bonded Explosive,PBX)冲击起爆爆轰成长的影响规律,考虑到炸药低压慢反应阶段的燃烧拓扑结构包含颗粒内部孔隙表面燃烧和颗粒外表面燃烧形式,以及装药密度的影响,引入燃耗因子和装药密度影响因子,改进了Duan-Zhang-Kim(DZK)细观反应速率模型。采用同一套反应速率模型参数,数值模拟各实验状态下HMX基PBXC03(87%HMX,7%TATB,6%Viton)的冲击起爆过程,数值模拟结果与实验测试结果均吻合较好,表明改进DZK反应速率模型可更好地描述和预测载荷和炸药细观结构对PBXC03冲击起爆爆轰成长过程的影响规律。在本研究装药和加载条件下,中等密度的炸药冲击起爆和爆轰成长最快;颗粒度越小,炸药越难点火,但一旦点火,爆轰成长最快。     

强约束下典型熔铸和浇注炸药的烤燃特性对比

利用自行设计的烤燃试验装置,以熔铸RHT-1和浇注GHL-1 2种典型炸药为研究对象,试验研究了厚壳体强约束下2种炸药慢速烤燃和火烧时的反应特性,并将试验结果与薄壳体和相关战斗部的烤燃结果进行了对比。研究表明:在所研究的厚壳体强约束情况下,浇注炸药火烧时的安全性显著优于熔铸炸药,而其慢速烤燃时的安全性略高于熔铸炸药;熔铸装药战斗部可以通过换装浇注炸药提高其安全性。     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.     

Overview of Anti-tank Mines

First the different anti-tank mines laying possibilities are shortly summarized： hand emplaced, with mine layers, ground or helicopter relatively topographical well defined, and with cluster systems of projectiles, rockets and aircraft dispensers. Then examples of the three generations of anti-tank mines are presented：Ⅰ generation： detonating only beneath the track; Ⅱ generation： detonating beneath the track and belly; Ⅲ generation： mines with off-route actions. Weight and cost comparisons are strongly favoring the off-route Ⅲ-generation mines.     

A Finite Element Analysis on Static Strength of a Complex Section

A static finite element analysis （FEA） of an impulsive controller section is presented. The boundary condition and a part of the loads are applied. Considering the grades of the stress around the holes being large, the dense grids are adjusted accordingly. Four cases with different loads are compared, thus the influences of different loads on the section are analyzed. Numerical results show that the maximum stress of the section is lower than the strength limit of the material, and the section will not be broken with the static loads.     

Discussion on Mechanism of Breech-Blow Caused by Propellant Charge

From the view point of launch safety caused by fracture of propellant charge, this paper points out that the safety criterion of pressure wave is inadequate to evaluate the launch safety of propellant charge based on the initial negative differential pressure and sensitivity tests. Generally, the maximum barrel pressure does not depend upon the intensity of pressure wave correspondingly. The pressure wave intensity can not describe the fracture degree of propellant charge in chamber and reflect the mechanical environment of propellant charge fracturing exactly and wholly. The evaluation criterion for launch safety of propellant charge should be built on the basis of depicting the fracture degree of propellant bed.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.