大口径牵引火炮改装灌注轮胎后射击稳定性研究

为研究灌注轮胎对火炮射击稳定性的影响,通过对炮膛合力、驻退机力和复进机力进行分析,建立全炮模型的各主要构件间的拓扑关系及对应的自由度;并在ADAMS进行火炮动力学仿真,得到不同射击角度火炮动力学特性曲线。仿真结果表明:灌注轮胎不仅不会对大口径牵引的射击稳定性产生影响,而且提升了火炮的射击精度。     

异型弹芯斜侵彻靶板的数值分析

分析了高速撞击过程中不同入射角的异型弹芯的斜侵彻运动.结合异型弹芯侵彻靶板试验,建立了三维有限元计算模型,应用有限元软件ANSYS/LS-DYNA进行仿真计算,得到速度为1.5 km/s时靶板侵彻变形过程中的应力分布图,给出了碰撞过程中任意时刻的速度、加速度及能量的变化曲线.根据仿真结果,得到异型弹芯入射角与侵彻深度的变化曲线,与试验进行了对比,数值结果与试验结果吻合较好.     

履带车辆强化行驶试验的平顺性仿真

履带车辆强化行驶试验的平顺性仿真的过程如下:先用仿真软件ATV建立某型履带式自行火炮虚拟样机,并根据强化试验路的设计指标,编写相应的路面文件,建立仿真路面.其仿真试验通过强化试验路面上得到的不同车速下车辆驾驶员位置的垂直振动和水平振动加速度及其均方根值,解算出振动加速度与路面及行驶速度的关系.     

引信设计用火炮内弹道曲线的Logistic经验公式

为了便于炮弹引信后坐运动机构的分析和计算,能使引信工作者只根据身管长度和炮口速度等少量参数就能获得弹丸膛内加速度近似曲线,运用Logistic函数拟合火炮内弹道的位移-时间曲线和速度-时间曲线,再对拟合得到的速度-时间曲线求导便得到了弹丸膛内加速度近似曲线.对76种制式火炮弹药内弹道曲线拟合结果进行分析和处理,得到具有普适意义的引信设计用火炮内弹道曲线的Logistic拟合经验公式.Logistic经验公式所拟合的弹丸膛内加速度曲线虽不如传统的余弦简化法和直线简化法拟合精度高,但为连续函数,形式简单,所需参数也少,便于在引信设计计算中应用.     

基于非线性二自由度模型多轴车辆转向特性分析

针对3轴车辆,通过建立非线性二自由度转向模型,开展转向特性分析,得到在轮胎大侧偏角情况下车辆的转向特性,仿真结果表明,转向行驶过程中,轮胎的侧偏角进入非线性范围,侧偏力对车辆转向特性产生明显影响,为多轴车辆转向特性分析提供理论支撑.     

基于RecurDyn和MATLAB的坦克底盘-火炮系统动力学联合仿真研究

为了对坦克底盘-火炮系统中火炮的振动特性进行准确描述,提出应用多软件联合仿真的方法,分别基于Recur Dyn和MATLAB建立坦克底盘多体动力学模型和炮控系统模型,二者相结合建立联合仿真系统模型;在稳定工况下,对坦克底盘-火炮系统高低向俯仰角振动特性进行仿真研究.结果表明:随路面不平度的增大和坦克行驶速度的提高,火炮高低向误差角变大,稳定性变差;所建联合仿真模型能够很好的模拟火炮的高低向俯仰角振动,联合仿真方法提高了模型的准确度和计算效率,为坦克在不同行驶条件下进行火炮射击提供了定位范围参考.     

火炮振动与射击密集度实验方法研究

大口径火炮炮口振动响应是影响火炮射击密集度的关键参数之一.目前还没有一种理想的实验测试系统能得到炮口振动位移和速度测试值.为了研究火炮振动和射击密集度相关性,分析了大口径火炮炮口振动响应实验测试现状,提出了大口径火炮摇架俯仰振动角位移是联系火炮振动与其射击密集度的可监测实验测试敏感量的观点.给出了实验测试方法和实验测试步骤,采用RecurDyn多体动力学仿真软件进行了刚柔混合动力学模型计算,模型仿真计算和实验测试结果初步验证了该试验方法的有效性.     

越野车轮胎卵石路面牵引性能有限元与离散元耦合仿真及试验验证

越野车轮与松软路面相互作用研究对提高越野车辆松软路面行驶性能有重要意义。针对有限元方法或离散元方法不能单独有效描述轮胎与松软路面相互作用的问题,基于室内单轮土槽试验,建立能表征越野车轮胎复杂力学特性和卵石路面散体介质特性的有限元轮胎-离散元卵石路面耦合模型。使用有限元仿真分析软件LS-DYNA对越野车轮胎在不同滑转率工况下卵石路面的牵引性能进行仿真实验,得到了轮胎牵引性能参数（轮胎牵引力、轮辋下陷量）以及它们随滑转率变化关系。研究表明,仿真结果与土槽试验结果的一致性良好,验证了越野车轮胎卵石路面性能评价有限元与离散元耦合模型及仿真分析方法的正确性。     

非线性迟滞振动系统仿真

在基于Matlab/Simulink仿真软件的基础上,建立了双折线恢复力的仿真模型。从非线性迟滞振动系统力学模型和simulink仿真程序对非线性迟滞振动系统进行了分析,并以非线性迟滞振动系统为例作了仿真。结果表明,Simulink软件编程简单,可靠性高,利用其对非线性振动系统进行仿真,很容易得到系统的位移、速度及加速度的时域曲线。     

火炮牵引虚拟试验技术研究

以某高炮和某加农炮为研究对象，利用MSC／ADAMS构建了虚拟试验环境。应用三维造型软件PRO／E建立了11条强化路面的三维模型和火炮牵引状态虚拟样机。对火炮在强化路上牵引进行了虚拟试验，为了确定安全的牵引试验速度，必须首先计算火炮悬挂系统的固有频率。参考悬挂系统的固有频率和路面谱，设计牵引试验车速，防止出现悬挂系统共振。通过与现场试验对比，结果吻合，表明虚拟试验可为制定试验方案和编写火炮牵引试验方法的国家军用标准提供科学依据。     

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.     

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.     

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.     

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.