Influence of shaped charge structure parameters on the formation of linear explosively formed projectiles

The research of LEFP (linear explosive forming projectile) is of great value to the development of new warhead due to its excellent performance. To further improve the damage ability of the shaped charge warhead, a special shell overhanging structure was designed to increase the charge based on the traditional spherical charge, in which case the crushing energy of LEFP could be guaranteed. LS-DYNA was used to simulate different charge structures obtained by changing the number of detonation points, the length of shell platform, the radius of curvature and the thickness of liner. The RSM (response surface model) between the molding parameters of LEFP and the structural parameters of charge was established. Based on RSM model, the structure of shaped charge was optimized by using multi-objective genetic algorithm. Meanwhile, the formation process of jet was analyzed by pulsed X-ray photography. The results show that the velocity, length-diameter ratio and specific kinetic energy of the LEFP were closely related to the structural parameters of the shaped charge. After the optimization of charge structure, the forming effect and penetration ability of LEPP had been significantly improved. The experimental data of jet velocity and length were consistent with the numerical results, which verifies the reliability of the numerical results.     

Novel aluminum-based fuel: Facile preparation to improve thermal reactions

To improve the thermal properties of aluminum (Al) in the energetic system, a coated structure with ammonium perchlorate (AP) was prepared by a facile approach. And N, N-Dimethylformamide (DMF) was chosen as an ideal solvent based on heterogeneous nucleation theory and molecular dynamics simulation. This coated structure could enlarge the contact area and improve the reaction environment to enhance the thermal properties. The addition of AP could accelerate oxidation temperature of Al with around 17.5 °C. And the heat release of 85@15 composition rises to 26.13 kJ/g and the reaction degree is 97.6% with higher peak pressure (254.6 kPa) and rise rate (1.397 MPa/s). An ideal ratio with 15 wt% AP was probed primarily. The high energy laser-induced shockwave experiment was utilized to simulate the reaction behavior in hot field. And the larger activated mixture of coated powder could release more energy to promote the growth of shockwave with higher speed up to 518.7 ± 55.9 m/s. In conclusion, 85@15 composition is expected to be applied in energetic system as a novel metal fuel.     

Dual-steering mode based on direct yaw moment control for multi-wheel hub motor driven vehicles:Theoretical design and experimental assessment

One of the main challenges for multi-wheel hub motor driven vehicles is the coordination of individual drivetrains to improve mobility and stability in the steering process.This paper proposes a dual-steering mode based on direct yaw moment control for enhancing vehicle steering ability in complex environ-ments.The control system is designed as a hierarchical structure,with a yaw moment decision layer and a driving force distribution layer.In the higher-level layer,the objective optimization function is con-structed to obtain the slip steering ratio,which represents the degree of vehicle slip steering in the dual-steering mode.A yaw moment controller using active disturbance rejection control theory is designed for continuous yaw rate control.When the actual yaw rate of the vehicle deviates from the reference yaw rate obtained by the vehicle reference model and the slip steering ratio,the yaw moment controller is actuated to determine the yaw moment demand for vehicle steering.In the lower-level layer,there is a torque distribution controller based on distribution rules,which meets the requirement of yaw moment demand without affecting the total longitudinal driving force of the vehicle.For verifying the validity and feasibility of the dual-steering mode,simulations were conducted on the hardware-in-loop real-time simulation platform.Additionally,corresponding real vehicle tests were carried out on an eight-wheel prototype vehicle.Test results were generally consistent with the simulation results,thereby demon-strating that the proposed dual-steering mode reduces steering radius and enhances the steering per-formance of the vehicle.     

Knowledge-oriented modeling for influencing factors of battle damage in military industrial logistics: An integrated method

Modeling influencing factors of battle damage is one of essential works in implementing military industrial logistics simulation to explore battle damage laws knowledge. However, one of key challenges in designing the simulation system could be how to reasonably determine simulation model input and build a bridge to link battle damage model and battle damage laws knowledge. In this paper, we propose a novel knowledge-oriented modeling method for influencing factors of battle damage in military industrial logistics, integrating conceptual analysis, conceptual modeling, quantitative modeling and simulation implementation. We conceptualize influencing factors of battle damage by using the principle of hierarchical decomposition, thus classifying the related battle damage knowledge logically. Then, we construct the conceptual model of influencing factors of battle damage by using Entity-Relationship approach, thus describing their interactions reasonably. Subsequently, we extract the important influencing factors by using social network analysis, thus evaluating their importance quantitatively and further clarifying the elements of simulation. Finally, we develop an agent-based military industry logistics simulation system by taking the modeling results on influencing factors of battle damage as simulation model input, and obtain simulation model output, i.e., new battle damage laws knowledge, thus verifying feasibility and effectiveness of the proposed method. The results show that this method can be used to support human decision-making and action.     

轴对称淹没水射流喷管内外紊流流场数值模拟

利用淹没水射流可对有机物进行降解.为研究淹没水射流降解的流场特性,根据轴对称淹没水射流撞击靶件的条件建立了物理模型,选用κ-ε紊流模型采用SIMPLEC算法进行数值计算.计算结果表明,流场存在射流区、漫流区、撞击区和漩涡区:射流区离靶件较远的部分同自由射流结构相似;靶件冲击面上压力分布近似的呈正态分布.对物理模型进行适当的改进并进行模拟,其结果同相应的实验数据相吻合,验证了本模型的可行性和计算结果的正确性.     

一种调频调相混合调制信号及抗干扰性能分析

针对线性调频信号形式简单,易被敌方截获和干扰的特点,提出了一类脉内线性调频和子脉冲相位调制相结合的具有多种变化形式的混合调制脉冲压缩信号。MATLAB仿真分析表明,与单纯线性调频信号相比,该混合调制信号产生和处理简单,既保持了线性调频信号的优点,又提高了抗截获和抗干扰能力。     

武器装备战斗损伤研究

以“通用武器雷达装备战损规律研究”成果为基础,系统阐述了开展武器装备战斗损伤研究的方法体系,介绍了战斗损伤建模与仿真、装备战斗损伤机理研究、装备战斗损伤分析、战斗损伤试验的相关技术和方法。     

坦克CGF炮长操作过程的可视化仿真

通过对坦克计算机生成兵力模型的内部操作行为进行视景仿真的必要性进行分析,建立了坦克计算机生成兵力模型内部操作行为的视景仿真模型。该模型以坦克内部炮长岗位为视点,实现了坦克计算机生成兵力模型各种射击操作的可视化。该视景仿真模型与同类型人在回路的仿真模型有着相同的视景仿真效果。通过该模型可以看出计算机生成兵力模型的状态变化过程和操作过程,仿真过程更加直观,仿真结果可信度更高。     

舰船回转运动时拖曳声纳阵位预报研究

根据船舶操纵性标准方程 ,预报了拖船水平面的操舵回转运动 ,由此确定船舶操舵回转时拖点的速度作为拖曳声纳运动预报的拖点边界条件 .利用拖缆回转运动计算程序 ,计算了船舶回转时拖曳声纳阵位 ,初步讨论了船舶操舵回转对拖曳声纳的影响 .     

基于WTK的装备维修训练虚拟现实系统建模与仿真算法

结合装备维修训练虚拟现实系统(VEMT)的研制,建立了基于WTK(虚拟现实工具包WorldToolKit)的VEMT层次结构模型和仿真场景图,并介绍了VEMT的主控模块仿真算法、场景图仿真算法、立体显示仿真算法和虚拟手抓取物体算法.