一种钢丝绳端头固定优化设计

为提高机械升降系统的可靠性和装备的使用效率,对钢丝绳端头连接强度进行优化设计.采用限位压接工艺,利用钢丝绳和端头之间的摩擦作用将端头与钢丝绳牢固结合,通过正交试验设计筛选并验证了优化的钢丝绳端头固定参数.试验结果表明:该固定方式结合强度高,安全可靠,能够满足军用装备的战备要求.     

相交立体相贯线解析求法

介绍了绘制相贯线的两种方法:图解法和解析法,给出了几个典型相贯体相贯线的具体解析求法和两回转体的某些相贯线是平面曲线的特殊情况,最后总结了若干特殊相贯线的性质.     

机动弹头端头分系统的热设计鉴定试验

在空军火箭推进实验室的端头试验设备上,进行了机动弹头端头分系统的防热结构试验,以鉴定端头分系统热设计的合理性和端头载荷探测器的工作性能。该试验大纲由下面三部分组成:传热及压力校准,烧蚀及载荷性能校验,以及全尺寸端头的热结构试验。端头分系统成功地经受了长达6.5秒的试验,达到了全部试验目的,从而证实该热设计是适于作飞行试验的。同时发现了测量方面能够加以改善的地方,并在飞行试验的测量中已作了改进。在飞行试验中,该端头分系统性能良好,同时获得了高质量的飞行试验数据。     

多个圆弧刻槽薄壁圆管轴向压溃吸能特性数值研究

为了降低薄壁圆管吸能结构的初始峰值载荷,获得稳定的平均压溃力,设计不同刻槽形式的薄壁吸能结构.分别在薄壁圆管外壁、内壁和内外交错预设多个圆弧凹槽,利用ANSYS/LS-DYNA有限元软件,分析不同刻槽类型对吸能特性的影响.计算结果表明:不同刻槽形式对薄壁圆管吸能量影响很大;相同条件下,内壁刻槽比外壁刻槽能够更多地降低初始压溃载荷.该研究对多个圆弧刻槽薄壁圆管轴向压溃吸能特性的研究有一定的参考价值.     

最小总加热量再入飞行器端头设计

对一个指定弹道系数和端头尺寸的再人飞行器来说,用直接优化法来确定细长比为固定的一种端头外形,使端头在整个弹道上的层流或紊流总加热量达到最小。这些约束条件忽略了端头外形与飞行器性能参数之间的相互影响,当考虑进这种相互影响并补充加上飞行器的质量与体积等于常量的新约束条件之后,则结果表明截锥形端头能导致总加热量达到最小。但本文没有打算为这些补充的约束条件进行端头外形的优化研究。     

相交立体相贯线解析求法

介绍了绘制相贯线的两种方法：图解法和解析法，给出了几个典型相贯体相贯线的具体解析求法和两回转体的某些相贯线是平面曲线的特殊情况，最后总结了若干特殊相贯线的性质．     

圆管与圆杆组合体对半无限均质钢靶侵御深度研究

依据圆管、圆杆初始撞击动能与弹坑体积之比相等的假设，建立了同材料圆管与圆杆对半无限均质靶板侵彻深度之比的简化理论模型。推导出圆管与圆杆的侵彻深度之比是两者的长度比、初始撞击速度比、坑径比和圆管内外径比的函数。在同一初始撞击速度、相同长度、圆杆直径不大于圆管内径条件下，对影响圆管和同长度同材料圆管与圆杆组成的圆管一圆杆异型侵彻体侵彻深度的参量进行了讨论，并给出圆管与圆杆侵彻深度之比的变化范围。圆管与圆杆侵彻深度之比在同材料同长度下理论计算值与实验数据有很好的一致性。所有这些都为伸缩式、大长径比新型动能穿甲弹结构设计提供了理论基础。     

激光束切割厚钢板

1.前言用激光热切割法切割厚度达5mm的钢板,已经不断地被某些工业部们所采用,例如,汽车工业部门。这些工业部门所采用的激光器功率达1KW。由于已有功率高达10KW激光器出售,因此,有可能采用如下三种方法切割较厚的钢板即氧-激光切割,激光升华切割和激光熔化切割。最常用的方法是氧-激光切割。割缝主要由割缝处材料燃烧而形成。激光束的作用实质上是把割缝区加热到熔点温度,而氧射     

喷嘴型面对膏体火箭内弹道的影响

为研究燃面变化对膏体火箭发动机内弹道调节精度的影响,根据膏体火箭发动机的工作原理,分别推导了直圆管喷嘴和锥形扩张喷嘴型面下的膏体推进剂燃面方程,建立了膏体火箭发动机零维内弹道模型,分析了喷嘴型面对发动机内弹道性能的影响,并进行了直圆管喷嘴发动机试验.结果表明,直圆管喷嘴下计算的点火时间比试验结果短,但平衡时间及平衡压强与试验结果基本吻合,喷嘴型面变化对发动机平衡时间影响很大.     

封闭式反方向切割

采用本文介绍的切割法,能全无毛刺地切割扁金属材料。受切板以不同于通常切割时的方式进行切割;切割过程分成三个阶段,且各阶段的切割工件的切割方向均相反。     

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.     

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.     

The Kinematics Analysis of the Hydraulic Mine-clearing Mechanical Manipulator

Through analyzing the kinematics of the hydraulic manipulator operating system, according to the rules for set-ing up the D-H coordinate system, the generalized coordinate of the manipulator system is established. The rotating and moving joints are selected from the mechanism as joint variables. Each generalized transformation matrix of joints is worked out. The kinematics equation at the finger end of the manipulator is calculated. The obverse solution for the manipulator is gained. The geometrical operating parameters and primary technical specification of the manipulator system are simulated through the computer. The simulative result has shown that the manipulator operating system meets the working task requirements. This research provides theoretical basis for optimizing structural parameters of the manipulator operating. So it also is justified the feasibility for mechanical manipulators to be used in the engineering equipment platform of the hydraulic excavator.