地面无人装备环境感知能力评价方法研究

地面无人装备已经成为全球重要的发展方向.在无人装备产品快速研发的同时,如何能更好地从实战出发,提出适用于无人装备作战使命和作战任务的装备性能试验测试指标,从而在竞争择优中筛选出真正好用、管用、实用的地面无人装备成为同等重要的研究课题.以地面无人装备最关键的环境感知能力为研究对象,借鉴美国国防部DoDAF多视角研究方案,...     

Shock-induced reaction behaviors of functionally graded reactive material

In this paper, the ballistic impact experiments, including impact test chamber and impact double-spaced plates, were conducted to study the reaction behaviors of a novel functionally graded reactive material (FGRM), which was composed of polytetrafluoroethylene/aluminum (PTFE/Al) and PTFE/Al/bismuth trioxide (Bi₂O₃). The experiments showed that the impact direction of the FGRM had a significant effect on the reaction. With the same impact velocity, when the first impact material was PTFE/Al/Bi₂O₃, compared with first impact material PTFE/Al, the FGRM induced higher overpressure in the test chamber and larger damaged area of double-spaced plates. The theoretical model, which considered the shock wave generation and propagation, the effect of the shock wave on reaction efficiency, and penetration behaviors, was developed to analyze the reaction behaviors of the FGRM. The model predicted first impact material of the FGRM with a higher shock impedance was conducive to the reaction of reactive materials. The conclusion of this study provides significant information about the design and application of reactive materials.     

Influence of a liquid-filled compartment structure on the incoming shaped charge jet stability

Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compart-ment structure can resist the shaped charge warhead effectively.This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles.On the basis of shock wave propagation theory,the influence of the liquid-filled compartment structure on jet sta-bility is analysed.The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined.In addition,the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the re-sidual jet are obtained.A theoretical model is validated against the experimental penetration depths.     

An efficient SPH methodology for modelling mechanical characteristics of particulate composites

Particulate composites are one of the widely used materials in producing numerous state-of-the-art components in biomedical, automobile, aerospace including defence technology. Variety of modelling techniques have been adopted in the past to model mechanical behaviour of particulate composites. Due to their favourable properties, particle-based methods provide a convenient platform to model failure or fracture of these composites. Smooth particle hydrodynamics (SPH) is one of such methods which demonstrate excellent potential for modelling failure or fracture of particulate composites in a Lagrangian setting. One of the major challenges in using SPH method for modelling composite materials depends on accurate and efficient way to treat interface and boundary conditions. In this paper, a master-slave method based multi-freedom constraints is proposed to impose essential boundary conditions and interfacial displacement constraints in modelling mechanical behaviour of composite materials using SPH method. The proposed methodology enforces the above constraints more accurately and requires only smaller condition number for system stiffness matrix than the procedures based on typical penalty function approach. A minimum cut-off value-based error criteria is employed to improve the compu-tational efficiency of the proposed methodology. In addition, the proposed method is further enhanced by adopting a modified numerical interpolation scheme along the boundary to increase the accuracy and computational efficiency. The numerical examples demonstrate that the proposed master-slave approach yields better accuracy in enforcing displacement constraints and requires approximately the same computational time as that of penalty method.     

基于Monte-Carlo方法的弹炮结合防空武器系统毁歼概率仿真研究

根据弹炮结合防空武器系统对空射击的特点,建立了其毁歼空中目标的数学模型,并在此基础上利用蒙特卡洛方法对模型进行了仿真分析,仿真结果贴近实验数据,为弹炮结合防空武器系统提供了一种用计算机仿真模拟来计算毁歼概率的方法,解决了用解析法计算毁歼概率所带来的诸多困难,为新型系统的设计、研制和评价提供了依据和必要的分析手段。     

反辐射无人机作战仿真研究

通过分析反辐射无人机的作战过程,给出了单架次反辐射无人机作战仿真软件逻辑框图,定义了多个对反辐射无人机装备论证和作战使用有指导意义的作战效能评估指标,并针对大量仿真结果,给出了各个指标值的计算方法。     

双速制声自导鱼雷主动开机时机研究

鱼雷主动声自导寻的信号是潜艇探测来袭鱼雷的主要信息源之一,主动声自导开机时机是鱼雷发射时需要设定的重要参数,它直接影响鱼雷攻击的隐蔽性。通过分析双速制鱼雷辐射噪声对潜艇鱼雷报警距离的影响,提出了一种双速制鱼雷直航搜索阶段的变速策略,在此基础上建立了鱼雷主动声自导开机时机解算模型,仿真结果表明,此方法简单高效,结论详实可信,对双速制鱼雷发射诸元解算具有一定的实用价值。     

TCP友好的路由器设计

TCP流是网络中主要数据流,TCP协议处理机制的研究有助于我们认知网络内部复杂特性,合理利用网络资源,这些对于路由器设计具有重要意义。根据TCP协议处理机制,在分析TCP协议加增倍减的拥塞控制模式对报文缓冲的影响和TCP流保序性要求对报文处理的影响的基础上,对路由器的设计中报文缓冲和报文分配等关键问题提出了TCP友好的解决方案。TCP友好的路由器设计有利于提高路由器处理能力。     

近距格斗规避方式研究

空中格斗过程中,当歼击机处于有利位置时,飞行员应操纵歼击机进行机动飞行以便能采用一定的攻击方式攻击目标飞机,当飞行员判断出空战态势对其不利时,往往采用一定的规避机动方法躲避敌机的跟踪和攻击。文中重点阐述了歼击机在空对空格斗状态下常用的几种规避机动方式:逃逸法、保持航向正切法和终端消极偏差法,给出了其定义,分析了其主要的运动特征,并对规避路线运动学方程及边界等运动特性进行了一定的研究。     

激光陀螺数字抖动控制方法与特性

针对传统的模拟抖动控制系统体积大、灵活性差的缺点,设计了一种基于单片机的新的激光陀螺数字抖动控制方法,建立了陀螺抖动的数学模型,比较研究了传统的模拟正弦波驱动和新的数字方波驱动的抖动特性,指出了后者不同于前者的抖幅变化律及非线性的随机噪声注入方式。仿真和实验证明,该方法能很好满足激光陀螺抖动控制要求,保证陀螺性能。