某型舰炮弹炮耦合对炮口振动影响的研究

针对炮口振动会影响舰炮系统发射状态的问题,运用ANSYS软件建立了某型舰炮的后坐部分动力学模型和弹炮耦合动力学模型。基于此模型,采用有限元分析法进行分析,得出:炮口处的振幅从开始逐渐增大,在弹丸出膛瞬间到达最大值,然后逐渐减小,直至减到最小值。分析结果表明:该方法能够较真实得模拟舰炮弹炮耦合过程,得到弹炮耦合对炮口振动的影响结果。     

基于神经网络和遗传算法的火炮结构动力学优化

为研究炮口扰动优化问题,提出采用非线性有限元、试验设计、神经网络和遗传算法相结合的方法进行火炮结构动力学优化。建立了某大口径火炮上装部分非线性有限元动力学模型,结合试验设计进行了火炮结构动力学分析。以试验数据为训练样本,建立了基于贝叶斯正则化算法的反向传播（BP）神经网络来模拟火炮总体结构参数与炮口扰动之间的非线性映射关系。构造了炮口扰动优化目标函数,利用遗传算法对目标函数进行求解,实现了火炮总体结构参数的动力学优化。研究表明所建立的火炮总体结构参数与炮口扰动之间的非线性映射关系具有很高的可信度,运用该方法进行火炮结构动力学优化行之有效。     

某舰炮主要部件固有频率研究

舰炮在发射过程中,不良的振动和冲击会使火炮系统性能变差,如振动使射击精度和射弹散布变差;为了提高舰炮射击精度和射击密集度,需要对舰炮系统动态特性进行深入的研究;通过分析各部件的固有频率可以预测部件之间是否存在共振;通过有限元分析得到炮口扰动数值的情况下,对其进行频谱分析,得到对扰动贡献最大的频率区间,研究各部件固有频率的合理性。     

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.     

自行高炮行进间射击炮口响应特性研究

为研究自行高炮行进间射击时的炮口响应特性,基于多体系统动力学、车辆地面力学、火炮发射动力学建立了自行高炮行进间发射动力学模型,运用谐波叠加法,对典型的自行高炮行驶路面进行重构。通过数值计算获得了不同行驶和射击工况下的炮口响应,分析了行驶速度、路面等级、射击载荷、射角等因素对自行高炮的炮口响应的影响。考虑了自行高炮结构非线性因素,运用有限元方法和接触碰撞理论,将柔性身管模型和滚珠座圈大规模接触碰撞模型应用于模型中。计算结果表明,随着行驶速度和路面等级的提高,炮口动态响应增大,行进间不同射击工况下,炮口响应情况有较大差异。研究结果为掌握自行高炮行进间射击炮口扰动规律提供了参考依据。     

大口径火炮反后坐装置及定向栓空间布置对炮口振动影响研究

大口径火炮发射系统总体结构布置是影响发射系统性能的关键之一,其决定着火炮架体结构设计和关键指标实现。火炮架体、反后坐装置和定向栓及其空间布置是火炮结构的重要组成部分,是发射系统实现射击精度的结构基础。开展大口径火炮发射系统反后坐及定向栓空间布置对炮口振动影响研究,从总体结构布置出发降低炮口振动,是从火炮结构设计角度提高火炮射击精度的重要研究内容之一。通过建立某大口径自行炮全炮的有限元模型,采用动力学方法仿真得到了全炮动力学响应,包括炮口点振动速度和角速度、前套箍受力等。分析了该自行炮反后坐装置及定向栓布置对炮口振动影响,结果表明,采用双定向栓设计能够减小炮口左右方向振动速度和角速度、减小前套箍受力;采用双定向栓和反后坐装置对称布置方案能够减小炮口振动量。该研究为优化大口径火炮火力系统方案提供了理论和工程技术参考。     

运动激励下身管动力学特性研究

身管振动是影响火炮射击精度的重要因素,针对弹丸膛内高速运动冲击下的身管振动问题,建立了移动弹丸作用下身管的横向振动模型,导出了无质偏弹丸激励下的动力学方程,并采用分离变量法求解了身管振动的动力学响应;对不同弹速激励下的身管振动响应进行了数值仿真,讨论了弹丸运动速度与炮口振动幅度的变化规律;研究结果表明:欲抑制火炮发射时的炮口振动,弹丸膛内的运动速度应尽量取得大些;建立的模型与采用的分析方法,亦可用于电磁轨道炮的动力学研究。     

某火炮反后坐装置布局方案数值模拟分析

反后坐装置布局对火炮的总体性能有重要影响,为了定量分析不同反后坐装置布局方案,建立了某火炮反后坐装置典型布局方案的有限元模型,对火炮主要架体进行了结构刚强度数值计算和对比分析。研究表明制退机和复进机空间对称布局方案有利于提高火炮刚强度,进一步的非线性有限元动力学数值计算及分析表明,这种布局方案也有利于减小对炮口振动的影响。     

影响炮口扰动的火炮总体结构参数灵敏度分析与优化

从减小炮口扰动的角度出发,利用ADAMS软件建立了某火炮发射过程的刚柔耦合模型,考虑了身管、摇架、上架的变形,通过灵敏度分析获得了火炮总体结构参数对炮口扰动的影响强弱;结合灵敏度分析结果,联合小生境遗传算法与ADAMS软件进行了火炮动力学的多目标优化分析,有效降低了炮口扰动,对火炮结构设计和动力学分析具有一定参考价值。     

自行火炮车体的非线性动态响应

本文根据非线性有限元的基本理论,利用非线性有限元动力学方程的数值积分方法和三维五节点接触单元的接触算、刚度矩阵和载荷列阵,通过非线性弹簧阻尼单元、接触单元等建立自行火炮发射过程的动力学非线性有限元模型,集中解决自行火炮的悬挂部分与地面之间的接触非线性问题,求解了车体的固有特性和非线性动态响应,为火炮发射动力学的研究提供了技术途径。     

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.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

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.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

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.