基于变结构方法的空空导弹鲁棒逆控制律设计

为克服动态逆控制严重依赖被控对象精确数学模型且鲁棒性较差的缺点,将动态逆与变结构方法相结合采用双环结构设计了空空导弹鲁棒动态逆控制律.将导弹飞行状态划分成快慢2个回路,慢回路(外环)采用变结构控制,并设计扩张状态观测器,对外环中的不确定性进行估计;快回路(内环)采用动态逆控制.仿真结果表明,所设计的控制律具有较好的动态特性和鲁棒性能.     

Sandwich structure for enhancing the interface reaction of hexanitrohexaazaisowurtzitane and nanoporous carbon scaffolds film to improve the thermal decomposition performance

Improving the thermal decomposition performance of hexanitrohexaazaisowurtzitane (CL-20) by appropriate methods is helpful to promote the combustion performance of CL-20-based solid propellants. In this study, we synthesized a sandwich structure of CL-20 and nanoporous carbon scaffolds film (NCS) and emphatically studied the thermal decomposition performance of the composite structure. Thermogravimetric analysis and differential scanning calorimetry were used to measure the thermal decomposition process of the composite structure. The kinetic parameters of thermal decomposition were calculated by the thermal dynamic analysis software AKTS. These results showed that the thermal decomposition performance of the sandwich structure of CL-20 and NCS was better than CL-20. Among the tested samples, NCS with a pore size of 15 nm had the best catalytic activity for the thermal decomposition of CL-20. Moreover, the thermal decomposition curve of the composite structure at the heating rate of 1 K/min was deconvoluted by mathematical method to study the thermal decomposition process. And a possible catalytic mechanism was proposed. The excellent thermal decomposition performance is due to the sandwich structure enhances the interface reaction of CL-20 and NCS. This work may promote the extensive use of CL-20 in the field of solid rocket propellant.     

Investigation of the shock compression behaviors of Al/PTFE composites with experimental and a 3D mesoscale-model

The responses of AI/PTFE reactive materials (RMs) under shock compression were investigated by a single-stage gas gun.A 3D mesoscale-model was established based on micro-computed tomography(micro-CT) slice images and confirmed with experimental results.In the high-pressure stage,the com-posites reacted partially,whereas there were no deviations between the partially reacted Hugoniot and the inert simulation results.The simulation reveals that the Teflon matrix melting on the high shock pressure.Melts and decomposition of the PTFE accelerated the diffusion of the atoms.Thus,the reactions of the Al/PrFE composites are more like a combustion rather than a detonation.     

Investigating the Desirability of Navy Aircraft Service Life Extension Programs

Building on prior work on optimal replacement of aging aircraft, this paper presents three methodologies to evaluate prospective aviation Service Life Extension Programs (SLEPs) and applies these methodologies to US Navy F/A-18E/F data. While considerable uncertainty remains as to the values of key parameters (e.g. the cost of F/A-18E/F SLEPs), the preponderance of the evidence available at this juncture favors undertaking SLEPs on F/A-18E/Fs rather than replacing them with new Joint Strike Fighters.     

和平时期网络舆论战的特点及对策刍议

作为一种软杀伤性的政治攻心战,网络舆论战已成为信息化条件下体系作战的一种重要作战样式。和平时期网络舆论战具有其鲜明的特点,即舆论传播的隐秘性和受众的广泛性,信息传递的迅速性和受众的自组织性,信息的海量性和受众注意的易转移性。对此,应积极利用互联网争夺意识形态领域的主导权,积极参与网上讨论并注意引导网络舆论风向,加强网络舆论战技术装备和人才队伍建设,为打赢信息化条件下的网络舆论战打下良好基础。     

基于价值工程的装备体系建设费用结构优化方法研究

科学、合理地配置费用对于加强装备体系建设、提高军队战斗力具有重要的现实意义。文章介绍了价值工程的基本原理,建立了基于价值工程的装备体系建设费用结构优化模型,并引入强制确定(Forced Decision)法,通过实例讨论了优化方法的可行性和实用性。     

浅析信息化体系结构在潜艇装备维修保障中的应用

分析了武器装备维修保障信息化的基本内涵,阐述了信息化体系结构的基本概念,在分析目前主流的信息化体系结构的基础上,对构建潜艇武器装备维修保障信息化体系结构需要解决的主要问题进行论述,并给出基于美国国防部体系结构框架规范的潜艇武器装备维修保障信息化业务活动模型。     

基于FEM/SPH算法的弹丸侵彻土体数值模拟

基于有限元法(FEM)和光滑粒子流体动力学(SPH)结合的算法,用数值模拟了钢质弹丸对钢筒约束土体的侵彻过程。基于ANSYS/LS-DYNA显式动力分析和LS-PrePost后处理软件,形象再现了钢质弹丸冲击作用下土体飞溅形成漏斗坑和直线通道的物理过程。侵彻深度计算结果与实验数据吻合较好,钢质弹丸的速度和加速度时程曲线图与理论分析一致,体现了FEM/SPH算法的精确性。研究结果表明FEM/SPH算法在模拟侵彻土体方面具有可行性和有效性。     

命中角对防护结构口部爆炸毁伤影响的数值分析

为研究装药命中角对防护结构口部爆炸毁伤的影响规律,对直墙拱结构进行了一系列爆炸模拟分析,得到了直墙拱结构拱顶、拱脚和直墙底3个位置的爆炸应力和位移时程曲线。通过分析这3个位置的应力峰值和位移峰值,发现随着装药命中角的增大,拱顶处竖直方向荷载减小,而拱脚处水平方向荷载增大;随着装药命中角的增大,拱顶处竖直方向位移变形减小,而拱脚处水平方向位移变形增大。模拟分析得到的命中角对防护结构口部爆炸毁伤的影响规律,可供防护工程设计时参考。     

钢管在冲击荷载作用下的变形与失效破坏

为研究钢管在弹体侵彻过程中的变形特点,基于ANSYS/LS-DYNA软件,采用Johnson-Cook模型,模拟了半球形弹体以不同速度正向冲击钢管时的非线性动力响应情况。结果表明：弹体速度越小,钢管的抗侵彻性能越好;弹体速度越接近临界破坏速度,钢管降低弹体速度的能力就越明显;弹体冲击钢管时,钢管上表面比下表面更容易产生大变形,消耗更多的弹体动能,并在抗侵彻过程中伴有局部凹陷、蝶形变形和贯穿现象。实验结果可为圆柱壳结构钢管在冲击荷载作用下的耗能分析提供参考。