超空泡航行体双层壳结构动力稳定性分析

针对超空泡航行体轴向受力特点,建立超空泡航行体双层壳结构有限元模型,对结构动力稳定性进行分析.数值计算表明,当壳间实肋板厚度增大或环向肋骨数量和尺寸增加时,动力失稳区域整体下移,不稳定激发频率下降,失稳区域宽度减小幅度较小;当壳间间距减小或纵向肋骨数量和尺寸增加时,双层壳结构动力不稳定激发频率上升,动力失稳区域宽度较大...     

基于单发地空导弹测试数据的武器精度检验

在地空导弹命中精度检验问题中,提出了充分利用单发导弹的测试数据进行命中精度的检验。该思想是利用χ2检验法对导弹速度的瞬时误差（系统误差）的方差进行检验,并给出了在测出导弹7、9、11个轨迹点条件下的2类风险临界值表,为武器精度检验提供了一定依据。     

中远程空空导弹目标截获概率仿真计算

分析了影响中远程复合制导空空导弹截获目标的主要因素,建立了捷联惯导误差模型、载机雷达观测误差模型、雷达导引头误差模型等,提出了用蒙特卡洛法的方法计算截获概率,并给出仿真实例.仿真结果表明了模型和算法的有效性和实用性,为分析捷联惯导、载机雷达等对目标截获概率的影响提供了方法和支持.     

考虑腐蚀因素的船体结构寿命预测方法

为建立考虑腐蚀因素的船体结构寿命预测方法,在分析现有常用的船体结构腐蚀损伤时变模型的基础上,根据舰船维修保障实际情况建立了考虑腐蚀防护系统作用时间和维修时间等因素的腐蚀时变模型。根据相关规范选择了船体结构腐蚀寿命标准,并建立了一种计算船体结构腐蚀寿命的方法。该方法建立了船体结构腐蚀寿命与腐蚀防护系统作用时间和修理时间等因素之间的量化关系,可以用于预测均匀腐蚀条件下船体结构寿命,也可以反过来指导腐蚀防护系统设计指标的选择和船体结构维修策略的确定。     

无线传感网络中多转发节点协作传输策略

协作通信是提高无线传感网络性能的有效技术.为此,针对能量采集的无线传感网络(EH-WSNs),提出多转发节点协作传输(Multi-relay Cooperative Transmitting,MRCT)方案.MRCT方案采用时隙切换/功率分配机制,优化解码信息和传输信息的功率分配;转发节点将所接收的信息进行放大——转发处理,并由将多个转发节点的信息合并后,再传输传感节点,进而提高吞吐量和安全能力.通过仿真分析了MRCT方案的吞吐量和安全中断概率性能.仿真结果表明,提出的MRCT方案的吞吐量和安全性能得到提升.     

Study of high-speed-impact-induced conoidal fracture of Ti alloy layer in composite armor plate composed of Ti-and Al-alloy layers

In order to understand the mechanism of conoidal fracture damage caused by a high-speed fragment-simulating projectile in titanium alloy layer of a composite armor plate composed of titanium- and aluminum-alloy layers, the ballistic interaction process was successfully simulated based on the Tuler-Butcher and GISSMO coupling failure model. The simulated conoidal fracture morphology was in good agreement with the three-dimensional industrial-computed-tomography image. Further, three main damage zones (zones I, II, and III) were identified besides the crater area, which are located respectively near the crater area, at the back of the target plate, and directly below the crater area. Under the high-speed-impact conditions, in zone II, cracks began to form at the end of the period of crack formation in zone I, but crack formation in zone III started before the end of crack formation in zone II. Further, the damage mechanism differed for different stress states. The microcracks in zone I were formed both by void connection and shear deformation. In the formation of zone I, the stress triaxiality ranged from-2.0 to-1.0, and the shear failure mechanism played a dominant role. The microcracks in zone II showed the combined features of shear deformation and void connection, and during the for-mation process, the stress triaxiality was between 0 and 0.5 with a mixed failure mode. Further, the microcracks in zone III showed obvious characteristics of void connection caused by local melting. During the zone III formation, the triaxiality was 1.0-1.9, and the ductile fracture mechanism was dominant, which also reflects the phenomenon of spallation.     

基于毁伤机理的常导反舰作战发射弹量计算

常导反舰作战已成为反击制衡对手的有效手段之一.针对现有发射弹量计算方法不适合常导反舰作战,分析了大中型水面舰船的毁伤机理,提出常导反舰作战发射弹量的计算方法,计算结果与兰德公司给出的研究结果基本一致.     

分布式电驱动履带车辆容错分配控制策略

分布式电驱动履带车辆的驱动电机数目多、分配维数高,主电机故障时,会严重破坏行驶的平顺性和稳定性,影响驾驶安全.针对主电机故障时动力重分配的问题,采用一种规则与故障因子约束分配律相结合的分配方法,提出了一种容错分配控制策略,提高电机故障时的动力性和安全性.然后构建了Matlab与RecurDyn联合仿真模型,进行了主电机故障时的直线和转向行驶仿真实验,表明所提出了容错控制策略能够大大提高车辆行驶的安全性和稳定性.     

Irreversible demagnetization mechanism of permanent magnets during electromagnetic buffering

The permanent magnets will be irreversibly demagnetized under high temperature and high velocity during the electromagnetic buffering. In this study, the magnetic field induced by eddy currents and the self-demagnetizing field of permanent magnet are taken into consideration together for demagnetiza-tion analyse. The magnetic Reynolds number is used to express the eddy currents demagnetization. The correction coefficient being expressed as the index of the air-gap width, the inner cylinder thickness, iron pole axial length and the permanent magnet demagnetization coefficient is introduced by magnetic path analysis to represent the self-demagnetization effect and the demagnetization extent. The electromag-netic buffer (EMB) prototype is tested under intensive impact loads of different strengths at room temperature. The accuracy of the nonlinear irreversible demagnetization finite element model is verified by demagnetization on damping force, velocity and displacement. Finally, high-velocity demagnetization and high-temperature demagnetization are analysed in order to obtain the distribution law of irre-versible demagnetization.     

现有军用光电装备快速智能化手段

近年来,人工智能技术在图像处理领域取得了突破性进展,使得目标识别和目标检测算法的性能得到大幅提高,也为军用光电装备智能化创造了有利条件。本文从算法、数据和计算能力等人工智能三要素入手,分析了快速实现军用光电装备智能化的有效途径及过程中可能面临的问题,指出:现有的技术理论基本满足装备升级需求,智能化过程中还应重点加强实时性算法的研究,提早对专用数据集的收集整理进行布局完善,采用低功耗高性能边缘计算设备为装备计算能力水平提升提供支撑等。同时,在工程化过程中仍存在部分实际问题,需根据装备进行个性化设计,以解决理论与应用之间的差距。最后,建议重点加强国产化水平与能力的提高,以实现关键技术自主可控。