Simplified Approach to Velocities of Axial Forward Projection Fragments from the End of a Warhead

A warhead with axial forward projection fragments is one of the most important forms of aimable warheads. For such warheads the axial forward projection fragments are placed at the end of the explosive charge and form a fragment beam with high fragment density and high speed by the blast, which will obviously increase the damage to the targets. Experimental data showed that the velocities of the forward projection fragments on the convex end of a warhead which was initiated at the opposite end do not match that predicted by the Gurney equation for cylindrical warheads. A new approach for addressing the velocities of fragments of this kind of warhead is proposed. Two limiting conditions are defined, i.e. for fragment on the circumference of a cylindrical charge and fragments on the end of cylindrical charge, respectively.     

Initiation Style Optimization of Aimed Warhead by Numerical Simulation

The kill characteristics of aimed warhead were studied. Emphasis on the improvement of initiation system, experiments and three dimensional numerical investigations were carried out. Simulation results of side three initiation points fit experiments well. Optimal initiation style is obtained through further simulation. It shows that the effective fragments and the effective kill energy of the optimal scheme increase 12.8% and 10.1% respectively.     

弹头目标的ISAR回波特性分析

针对弹道导弹目标进行逆合成孔径雷达(ISAR)成像问题,对沿轨道高速运动并同时伴有自旋的弹头ISAR回波特性进行了分析.首先建立了弹头目标的运动模型和ISAR回波模型,将弹头的自旋矢量沿雷达视线方向和垂直于雷达视线方向进行分解,然后分别分析了弹头目标的轨道运动和自旋对回波信号的影响,最后进行了仿真分析.理论分析和仿真结果表明:弹头目标沿轨道的高速运动会使目标散射点产生严重的越距离单元徙动,而弹头的自旋会使目标散射点产生严重的越多普勒单元徙动,并使回波多普勒谱展宽,因而这两者都必须进行补偿.     

基于SIMBOX的导弹杀伤空中目标的视景仿真研究

研究了一种基于SIMBOX的导弹杀伤空中目标的视景仿真方法。介绍了空空导弹对目标的杀伤概率模型及其影响因素,文中分别给出了攻击区、制导误差规律、引信引爆点散布规律、引信引爆概率、目标坐标杀伤概率的计算模型,确定了杀伤概率模型。在SIMBOX平台上,以破片式战斗部为例进行了仿真计算,给出了直观的视景仿真三维动画过程。文中通过对仿真结果进行分析,指出了目标初始速度与瞄准线的夹角和目标及导弹速度会对杀伤概率产生影响,证明了所建的模型具有较高的可信性和可依赖性。     

Initiation behavior of covered explosive subjected to reactive fragment

Reactive fragment enhances lethality by incorporating the defeat mechanisms of kinetic energy and chemical energy into a unitary damage unit.Combined studies on the behavior of reactive fragment initia...     

子母弹抛撒技术及其内弹道计算

用气体动力学理论分析了子母弹抛撒技术 .分析表明 ,前开舱二级抛撒可用于数目较少的制导子导弹 .利用数值计算方法计算了该二级抛撒的内弹道性能 ,得到了高、低压室压力和子导弹的速度等性能曲线     

轴向增强型战斗部对导弹目标毁伤评估的可视化仿真研究

将修正广义射击线和粒子系统二种可视化仿真技术相结合,提出了基于计算机描述的轴向增强型战斗部威力模型和基于计算机有限网格(面元)的弹目作用模型,并结合计算机可视化仿真技术和模型构建技术开发了目标毁伤可视化仿真评估平台.以该评估平台就某轴向增强型弹药对ARM导弹目标的毁伤效果进行了仿真,结果表明上述模型可以很好的描述轴向增强型战斗部威力特性,不仅可提供在非试验条件下战斗部的设计依据,而且可形象直观地给出毁伤作用过程.     

用弹道摆测定球形破片侵彻钢质甲板后效动能实验研究

本文介绍用弹道摆测定球形破片侵彻钢质甲板后效动能的尝试,内容包括实验设计、实施、实验数据处理和结果分析,所得结论对大口径杀伤爆破战斗部设计和轻型装甲车辆毁伤标准研究有一定参考意义。     

Numerical simulation of shock initiation of the coated-type projectile penetrating target

The behavior of the charge initiation of the coated-type projectile penetrating target is researched by means of numerical simulation. The influences on charge initiation of the projectile shape, shell thickness, charge diameter, and projectile velocity are analyzed. Results show that projectile shape takes an obvious impact on critical detonation velocity, that for the projectile with the same quality, it is more vulnerable for the cylindrical projectile with the one length-diameter ratio to occurring shock initiation than the spherical projectile, the charge diameter is an important factor that affecting critical detonation velocity, which significantly decreases as the charge diameter increases.     

Research on Designing Profiled Rod Warhead

A new Kinetic Energy Rod (KER) warhead named profiled rod warhead is proposed in this paper. Based on the design of profiled rod warhead, a model of profiled rod driven by detonation is established. The detonation process is simulated by ANSYS/LS-DYNA, and the deployment velocity and initial flight attitude of rod are achieved. In addition, static rod deployment testing are performed to investigate the damage effect, the spatial flight attitude and deployment velocity. A satisfactory agreement is obtained by the comparison between numerical results and testing results. Meanwhile, the profiled rod studies are conducted to determine a higher penetrability compared with traditional cylindrical rods. Rigid body dynamics equations of profiled rod, which accounts for the influence of air resistance, are set up to predict the flight trajectory of long-distance. The results show that the profiled rod may provide a better penetration angle which still maintains a significant penetrability against projectiles when the rods move off long-distance range.     

航空炸弹杀爆战斗部综合毁伤分析研究

战斗部综合毁伤是战斗部最重要的特性,也是衡量战斗部设计优劣的重要指标之一.预制破片的速度是战斗部综合毁伤很重要的指标.针对目前战斗部爆炸破坏机理需完善和试验费用昂贵的现状,基于理论计算和数值模拟分析了战斗部的综合毁伤.本文对杀爆战斗部的静态和动态杀伤威力、毁伤概率等综合毁伤指标进行了分析,计算结果与试验测试数据较为吻合,对新产品研制、论证具有一定的参考价值.     

“10·10”西藏白格滑坡运动特征反演分析

为获取“10·10”白格滑坡运动规律与特征，基于“10·10”白格滑坡发育的3大区（启动区、堆积区、冲击区）和6个运动阶段（主体失稳破坏、牵引区启动、高速临空滑跃、冲击对岸、折返相撞及水砂射流、堆积坝次级滑移）,对滑坡碎屑体堆积状态及其在四川岸的冲击形态进行分析。采用谢徳格尔法及能量转化计算方法，选取滑坡体冲击高度的5个特征点，计算滑坡碎屑体在各运动阶段的运动速度。结果表明：主滑区阻滑区滑体以2.2 m/s的初速度启动，从启动区至剪出口，速度不断增大，5个特征点达到最大速度，分别为H₁ 67.0 m/s、H₂ 73.0 m/s、H₃ 73.7 m/s、H₄ 73.2 m/s、H₅ 68.3 m/s;牵引区滑体到达剪出口时，速度为70.2 m/s;主滑区阻滑区滑体的滑动速度具有从中间向两端递减的态势，其中滑坡主滑方向的中间位置速度最高，达73.7 m/s;滑体整体剧动时所释放的能量E至少为10^10.8J,引起震动相当于4.0～4.7级的表层基岩地震。通过滑坡...     

基于电磁散射数据的进动目标微多普勒仿真与分析

以旋转对称锥柱体弹头为研究对象,建立了目标进动模型,推导了不同类型散射中心的微多普勒理论公式,给出了一种基于静态电磁散射数据仿真进动目标微多普勒的方案．最后,对进动目标的微多普勒进行了仿真实验,验证了理论分析和仿真方案的正确性,实验结果表明基于电磁散射数据仿真的微多普勒可以反映目标较为真实的散射机理,为后续弹道目标特征的有效提取与识别奠定了基础．     

超高速破片对双层靶碰撞效应研究

研究了超高速破片碰撞双层靶形成碎片云的分布特点．在一定合理假设的前提下提出了一个供工程计算用的碎片云均匀分布模型，根据碎裂过程中产生的表面面积的表面能与局部惯性或动能相互成平衡的原理进行计算．利用能量守恒原理得到了超高速破片碰撞空间靶板结构形成的碎片尺寸、质量分布、碎片数量和碎片运动规律，可进一步求出碎片云特征破坏参数，为研究空间结构防护与毁伤提供设计依据．     

超高速破片对双层靶碰撞效应研究

研究了超高速破片碰撞双层靶形成碎片云的分布特点.在一定合理假设的前提下提出了一个供工程计算用的碎片云均匀分布模型,根据碎裂过程中产生的表面面积的表面能与局部惯性或动能相互成平衡的原理进行计算.利用能量守恒原理得到了超高速破片碰撞空间靶板结构形成的碎片尺寸、质量分布、碎片数量和碎片运动规律,可进一步求出碎片云特征破坏参数,为研究空间结构防护与毁伤提供设计依据.     

Heat Transfer Between a Missile＇s Combustion Chamber and the Warhead

Under higher temperatures the charge within a warhead will be subjected to physical and chemical changes, which will influence the security of the warhead launching process. In this paper the problem is studied adopting finite difference method for the case of a rocket-powered missile. Temperature distribution tables are giv-en through quadrature experiments, and the results fit the actual measured values very well. The results also show that to ensure the launching security of rocket-powered missiles having warhead charge critical temperature close to about 60℃, the designer can select appropriate heat insulation structural parameters.     

外环流气提式反应器液体局部动力学的实验研究和数值模拟

在外环流气提式气液反应器内,分别以空气和质量分数5%羧甲基纤维素(CMC)水溶液为气相和液相,对液相局部动力学进行了系统研究。应用电极示踪测试技术(ETM)测定了下降段液体速度;应用计算流体力学软件FLUENT 6.0对上升段的液体湍动能和湍动能耗散率进行了模拟计算。模拟结果表明:气体分布器对液体湍动能和湍动能耗散率有较大影响,液体湍动能和湍动能耗散率随表观气速的增大均增大,且液体湍动能呈现出较对称的波动模式。在低气速下,局部液体速率的模拟结果与实验数据吻合良好。     

Heat Transfer Between a Missile''''s Combustion Chamber and the Warhead

Thecombustionofpropellantacceleratesawar headduringtheprocessoflaunchingofthewarhead .Theheatcomingfromthecombustionnotonlypro pelsthewarheadbutitisalsotransferredtothechargewithinthewarhead.Tothepropellantcharge,spacebetweenthecombustionchamberandthewarheadneedstobewelldisposedininsulation ,andthedesignofheatinsulationstructureisveryim portantforsecurelaunching .Thusfarrelevantstud iesconcentratelargelyontheaspectsoftheouterspaceengine,andmostanalysesaregivenonthetem peraturedistributionofthe…     

基于立体视觉的数字图像相关方法在爆破抛掷作用研究中的应用

爆破抛掷物能否按照设计运动直接决定爆破工程的成败。为进一步研究爆破抛掷作用过程,量化研究抛掷物运动状态,本文采用数字图像相关和立体视觉原理,建立了爆破抛掷物运动观测系统。应用该系统观测了混凝土模型爆破试验过程,通过数字图像相关匹配算法进行抛掷物的跟踪,通过立体视觉技术计算抛掷物三维运动轨迹坐标,进而得到了其运动速度。结果表明,抛掷物的运动过程可分为整体加速运动和分散减速运动两个阶段。在第一阶段：在爆生气体推动下,抛掷物以一整体做加速运动,此阶段持续时间9ms,在6.5ms时抛掷物脱离爆破漏斗,最大速度可达16.63~19.65m/s;在第二阶段：抛掷物逐渐破裂、分散成块,处于不同区域、不同形状的碎块运动状态均不同,表面碎块的速度最大,可达26.24m/s,是潜在的爆破飞石,其只受到重力和空气阻力作用,做减速运动;中下部碎块在残余气体推动下,同样做减速运动,但减速缓慢,速度为9~16m/s;薄片状碎块在飞行中不断翻转,消耗自身动能,其中速度最小的仅为5~6m/s。整体运动阶段简单,而分散运动过程较复杂,除爆破参数、介质自身性质外,抛掷物碎块的形状、所处位置也会影响其运动状态,抛掷物表面碎块速度最大,更易形成爆破飞石。本文为量化研究爆破抛掷作用和预测爆破飞石提供了一种有效的新方法。     

Anti-impact and energy-absorption of metal and compound thin-wall cylindrical tubes

The paper presents an energy iterative method to determine the second critical velocity by comparing the time histories of the kinetic energy and the buckling deformation based on the finite element model of the impact system. To design anti-impact structures of the thin-wall cylindrical tubes with this new method, the cost of the experiment can be considerably reduced. The feasibility and validity of this method are demonstrated by a dropping hammer experiment. In addition, this paper deals with the influence of constrained damping layers on the anti-impact capability and energy-absorption of thin-wall cylindrical tubes. Results show that the constrained damping layers make the energy-absorption and the anti-impact capability increased comparing with the naked tubes; the thickness of the damping layer should be restricted in a range, or else the anti-impact capability will decrease with the increase of the damping layer thickness; for the constrained layer, the anti-impact capability will increase with the augment of its thickness.