陶瓷/铝合金复合装甲倾角效应研究

采用12.7mm穿甲枪弹,进行陶瓷/铝合金复合装甲在不同倾角条件下抗弹侵彻试验,研究倾角效应对抗弹性能的影响。研究结果表明:陶瓷复合装甲的倾角效应为正效应,即随着倾角增大,陶瓷的抗弹性能提高;弹靶作用时陶瓷面板中倒陶瓷锥的形成是陶瓷复合装甲抗弹性能提高的主要原因。     

弹丸低速贯穿纤维与金属组合薄靶板的试验研究

为研究半穿甲战斗部动能侵彻下舰船舷侧复合装甲结构的抗穿甲机理,以均质钢板前置复合材料板模拟舰船舷侧复合装甲结构,采用低速弹道冲击试验,研究了结构的典型破坏模式和吸能机理,分析了前置复合装甲板的面密度对组合结构靶板整体抗穿甲性能的影响。在此基础上,根据靶板的破坏模式,得到了球头弹丸低速贯穿组合靶板的剩余速度预测公式。结果表明,组合靶板在弹丸低速冲击下主要呈现局部破坏,前置复合装甲板的破坏模式主要为纤维拉伸断裂,迎弹面存在少量的纤维剪切断裂,而钢质背板则主要呈现花瓣开裂破坏;组合靶板的整体抗弹性能随前置复合装甲板面密度的增加而提高;将理论预测剩余速度值与实验结果进行了比较,二者吻合较好。     

加筋板架结构与均质靶板等效关系的数值分析

为使用廉价均质钢等效替代加筋板架结构进行弹丸威力考核试验,运用LS-DYNA软件对板架结构和均质靶板的弹体穿甲过程进行数值模拟,分析了均质靶板的厚度和加筋板架结构不同弹着点对弹头穿靶能力的影响,并基于剩余速度理论,运用数值模拟和统计概率分析相结合的方法,建立了加筋板架结构与均质靶板之间的等效关系。结果表明：在工程应用上使用37 mm厚的均质靶板可替代给定加筋板架结构进行战斗部穿靶能力的考核。     

穿甲过程中薄靶等效关系研究

研究了斜置-垂直靶板在抗穿甲过程中的等效关系,建立了穿甲弹对垂直及斜置薄靶板射击的模型,利用Autodyn软件对侵彻深度进行了数值模拟,并通过实弹射击加以验证,证明了数值模拟的正确性;最后得出薄靶板在抗穿甲过程中,斜置-垂直靶板不能简单的进行等效,并给出了靶板进行等效的定性关系。     

钛合金板抗12.7mm穿甲燃烧弹倾角效应试验研究

采用12.7 mm穿甲燃烧弹对水平厚为25.5 mm的Ti-6Al-4V钛合金板进行倾角效应试验,以研究钛合金板倾角对其防护能力的影响。采用等重钢总穿深的方法考核其抗弹性能。结果表明:钛合金板抗小口径枪弹(12.7 mm穿燃弹)倾角效应的基本规律呈现正效应,对于水平厚为25.5 mm的钛合金板,其跳弹角为62°。     

铝合金板抗枪弹倾角效应试验研究

用7.62 mm和12.7 mm穿燃弹对不同厚度的均质铝合金板进行倾角效应试验,以研究铝合金板倾角对其防护力的影响。在试验中均以弹丸在标准弹速下对后效板的残余穿深或对靶板的总穿深来作为衡量抗弹性能的指标。对这两种穿燃弹而言,小角度时,装甲防护力比0°角时低,随着倾角增大,防护力逐渐提高。     

反舰导弹动能穿甲效应中倾角的影响

半穿甲反舰导弹战斗部侵彻目标的角度具有不确定性.从理论上给出了薄板花瓣破坏的模型后,采用ANSYS/LS-DYNA有限元分析软件对弹体不同倾角攻击目标的终点效应进行了分析.穿甲过程中,弹体和目标板选择了考虑应变、应变率和温度效应的Johnson-cook材料模型,分析了不同倾角对穿甲过程中弹体剩余速度及弹头姿态的影响.结果表明对于倾角效应来说,小角度时反舰导弹半穿甲战斗部穿甲能力略有提升;随着倾角增大,导弹穿甲能力降低甚至跳弹.     

穿甲模拟弹侵彻不同厚度钛合金靶板的数值分析

运用AUTODYN非线性显式动力学程序对不同厚度钛合金靶板受105 mm钨合金穿甲模拟弹的侵彻过程进行数值模拟计算,给出钛合金靶板的厚度效应规律:钛合金靶板抗105 mm穿甲模拟弹的相对防护系数N与靶板厚度b间的关系曲线近似躺倒的"S"形状,随靶板厚度b的增加,相对防护系数值N先降低后增大又降低;钛合金靶板厚度b≤50 mm时,随厚度b的增大,靶板对105 mm钨合金穿甲模拟弹的动能消耗线性单调增大。     

半穿甲战斗部对加筋靶板和均质靶板垂直侵彻的实验研究

文中以航母等大型舰船特有的筋板结构为目标,设计制做了缩比模拟加筋靶,同时参考国内外相关文献,设计了适合于毁伤航母的半穿甲战斗部实验弹.用实验弹对加筋靶和均质靶进行靶场垂直侵彻试验,得到了多种击靶条件的终点弹道参数和靶板毁伤破坏模式,为半穿甲战斗部对航母典型结构侵彻的机理研究提供基本的实验现象及数据,为高效毁伤大型舰船结构的半穿甲战斗部设计,提供一种技术支撑.     

舰舷结构与均质靶板等效关系的基本方法

按照能量等效原则,以穿靶后战斗部的剩余速度相等为基础,运用统计概率分析方法,建立了舰舷结构靶板与均质靶板之间的等效关系.在以打击舰船为目标的半穿甲战斗部穿靶能力试验中确定相应均质靶板厚度,以达到简化试验用靶板及显著减少试验次数的目的.     

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.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

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.     

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.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

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.     

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.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.