运动激光辐照圆柱薄壳温度场的数值模拟

对圆柱薄壳在四种不同运动模式激光源辐照下的温度场分布进行了分析研究。运用傅立叶级数展开法推导了在不同运动模式激光源作用下圆柱薄壳温度场的解析表达式,并对该解析表达式进行了编程计算,其计算结果与有限元解吻合良好。详细分析了旋转角速度与平动速度对圆柱壳温升分布的影响,发现在往复运动加热模式下光斑区域的温升变化最为剧烈。计算结果为导弹的抗激光辐射提供了理论依据。     

探空火箭级间段的CAD系统

本文在CADKEY绘图软件包的支持下,开发了加筋圆柱结构CAD系统—Hcadx.此系统通过菜单引导用户的操作,可用经验公式或解析法作轴压稳定分析,用罚函数法优化参数,可以在不退出Hcadx的情况下启动CADKEY,自动绘制设计草图。此草图经过适当地编辑、修改、便可成为工程中能接受的工作图纸。     

基于SysML的车辆信息系统设计

针对目前车辆信息系统缺乏有效设计方法的现状,结合新时期车辆信息系统的特点,提出了一种基于SysML的车辆信息系统设计方法。该方法明确了车辆信息系统设计过程的阶段和产物,并通过标准建模语言SysML的运用,用模型来支持系统的设计和有效性验证。该方法在智能巡航系统的设计中得到了运用。实践结果表明,该方法不仅能够自顶向下完整地设计系统、利用可视化的语言准确清晰地描述系统,而且能够在系统设计层面对系统功能逻辑和数据流进行动态仿真和迭代验证。该方法能够较好地指导新时期车辆信息系统的设计过程,满足信息系统的设计要求。     

大误差条件下尾流自导鱼雷齐射间隔问题

当目标运动要素误差较大时,可组织尾流自导鱼雷双雷齐射.阐述了尾流自导鱼雷平行航向齐射组织方法及数学模型.在一定条件下,仿真分析了目标速度、目标航向和目标距离存在大误差时,至少1条鱼雷捕获目标尾流概率随鱼雷间隔的变化规律,最后根据仿真结果给出了鱼雷间隔设置建议.     

MF-CFI: A fused evaluation index for camouflage patterns based on human visual perception

The evaluation index of camouflage patterns is important in the field of military application. It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism. In order to make the evaluation method more computationally intelligent, a Multi-Feature Camouflage Fused Index (MF-CFI) is proposed based on the comparison of grayscale, color and texture features between the target and the background. In order to verify the effectiveness of the proposed index, eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index (UIQI), Camouflage Similarity Index (CSI) and Structural Similarity (SSIM). Twenty-four different simulated targets are designed in a grassland background, 28 observers participate in the experiment and record the eye movement data during the observation process. The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data, both in the designed digital camouflage patterns and large-spot camouflage patterns. Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception, the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms.     

多武器平台目标域协同射击控制模型研究

目标域协同射击控制模型是在单平台火控系统空域窗射击控制、射击门控制等基础上,针对多武器平台对点目标或面目标协同射击的需求,进行了目标域和射击效能的定义,提出了空间/时间复合三维射击门的概念,设计了三维射击门模型,分别建立了多武器平台对点目标射击控制模型和多武器平台对面目标射击控制模型,通过对多武器平台协同射击效能的计算分析,证明了目标域协同射击控制模型可显著提高多武器平台协同射击对目标的火力打击效能.     

中国近海海空联合作战环境风险综合区划方法

针对中国近海海空联合作战环境风险区划问题,选取水面舰艇航行、舰载机飞行、海上人员训练等作战样式,大风、大浪、低云低能见度、湿热、风寒等环境要素,高值频率、概率极值、平均强度、气候趋势等指标,利用层次分析法和互反判断矩阵建立四层评价体系并进行区划.该方法可根据装备设计及环境适应标准对各指标进行影响排序,能有效区分不同季节和动力机制的环境要素差异、综合考虑不同类型风险影响.区划结果证明,海空联合作战环境风险由各兵种作战风险综合决定,主要受秋冬季盛行大风、夏秋季热带气旋、春夏季低能见度、冬春夏季低云、夏季湿热指数、冬季风寒指数等影响.     

Real-time prediction of projectile penetration to laminates by training machine learning models withfinite element solver as the trainer

Studies on ballistic penetration to laminates is complicated, but important for design effective protection of structures. Experimental means of study is expensive and can often be dangerous. Numerical simu-lation has been an excellent supplement, but the computation is time-consuming. Main aim of this thesis was to develop and test an effective tool for real-time prediction of projectile penetrations to laminates by training a neural network and a decision tree regression model. A large number of finite element models were developed;the residual velocities of projectiles fromfinite element simulations were used as the target data and processed to produce sufficient number of training samples. Study focused on steel 4340tpolyurea laminates with various configurations. Four different 3D shapes of the projectiles were modeled and used in the training. The trained neural network and decision tree model was tested using independently generated test samples using finite element models. The predicted projectile velocity values using the trained machine learning models are then compared with thefinite element simulation to verify the effectiveness of the models. Additionally, both models were trained using a published experimental data of projectile impacts to predict residual velocity of projectiles for the unseen samples. Performance of both the models was evaluated and compared. Models trained with Finite element simulation data samples were found capable to give more accurate predication, compared to the models trained with experimental data, becausefinite element modeling can generate much larger training set, and thus finite element solvers can serve as an excellent teacher. This study also showed that neural network model performs better with small experimental dataset compared to decision tree regression model.     

Fullerene bisadduct stabilizers: The effect of different addition positions on inhibiting the autocatalytic decomposition of nitrocellulose absorbed nitroglycerin

To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose (NC)/nitroglycerine (NG), we synthesized N-(4-methoxy) phenylpyrrolidine-C₆₀ and four different of bis(N-(4-methoxy) phenylpyrrolidine)-C₆₀ compounds through Prato reaction. Their structures were characterized by UV–vis, ¹H NMR, ¹³C NMR, high-resolution mass spectroscopy, and single-crystal X-ray diffraction. Their stabilization effect to NC/NG were investigated using differential scanning calorimetry, methyl violet, vacuum stabilization effect, weight loss, and accelerating rate calorimeter tests. The results indicated these compounds had excellent stabilization effect to NC/NG. The stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C₆₀. Moreover, the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different, and its stabilization effect to NC is also different. The stabilization effect order of different bisadduct isomers to nitrocellulose is as follows: e-edge > trans-2> cis-2> trans-3. Electron paramagnetic resonance (EPR) and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/NG. The EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide, and their ability is better than that of the monoadduct and C₆₀, which is consistent with the results of stabilization effect performance test.     

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。