基于神经网络和模糊综合评判的梁故障诊断研究

设计了一个简单的人工智能故障诊断系统模型,它包括知识库、模糊推理、神经网络和控制模块等。模糊推理模块利用模糊综合评判方法进行故障的预诊,神经网络模块采用竞争学习方法完成故障的确诊。文中对悬臂梁的单一故障和复合故障等七种模式进行了诊断分析,均获得了正确的诊断结果。     

区域结构及多尺度纹理分析

结合纹理的结构分析方法 ,提出一种区域状结构 ,并把这种结构作为尺度空间中的特征。在基于区域状特征结构的尺度空间中 ,结构状纹理分析可转化为尺度空间中对特征结构的分析 ,从而实现了对纹理的多尺度分析。理论分析和实验结果证明了这种分析方法的有效性     

微型计算机在复合材料强度准则研究中的应用

文中论述了运用微型计算机(IBM-PC)进行复合材料强度准则研究的方法,包括强度包络线绘制、双向加载数据采集及实验数据处理等,同时还研究了如何确定双向试验中的破坏载荷值,并在分析实例中提供了较详细的数据。     

球磨时间对纳米SiO_2/Cu复合材料摩擦学性能的影响

采用球磨法与热压烧结工艺制备了添加w（n-SiO2）=1.0%的铜基纳米复合材料。通过球盘式摩擦磨损试验机测试了复合材料的摩擦磨损性能,采用排水法和场发射扫描电镜（FSEM）研究了复合材料的致密度、显微组织和磨损形貌。结果表明：球磨可提高复合材料的致密度,改善n-SiO2在铜基体中的分散均匀性;随球磨时间的增加,复合材料的动摩擦因数和磨损量先减小后增加,球磨10 h复合材料具有较低的摩擦因数和磨损量,磨损机理主要为磨料磨损。     

加肋凹锥-环-柱结合壳结构参数分析

采用分区样条等参元法,分析了加肋凹锥 环 柱结合壳的应力和稳定性特点,研究了各项结构参数变化对结合壳应力和稳定性的影响,认为加肋凹锥 环 柱结合壳能有效降低锥柱结合部的纵向弯曲应力,但对于降低环向应力效果有限,建议在环壳段中部增加一档肋骨;半锥角的凹结合壳越大,嵌入环壳段的优势越明显;增大环壳与柱壳半径比可以有效降低环壳段中部的纵向弯曲应力.     

用结构自适应前馈网络解算多目标导弹攻击区

多目标导弹攻击区的实时解算是机载多目标攻击武器系统得以技术实现的中心环节。阐述了“多目标导弹攻击区”的概念 ,探索了其解算的技术途径 ,提出了“实时、高精度和低存储”的解算要求。根据上述技术要求 ,设计了基于网络灵敏度统计分析的多层前馈网络结构自适应算法 ,以用于训练合适规模的多层前馈网络逼近器。在此基础上 ,进行了系统仿真研究 ,研究的结果表明了该方案的应用前景。     

Resistance of grid steel-tube-confined concrete targets against projectile impact: Experimental investigation and analytical engineering model

Steel-tube-confined concrete (STCC) targets are provided with excellent anti-penetration performance over semi-infinite concrete (SIC) targets since the steel tube imposes passive restraint on the in-filled concrete during the penetration process. Grid STCC system with square steel tubes is a potential solution to protective structures. In this paper, experiments of 9-cell grid STCC targets penetrated by 12.7 mm Armor Piercing Projectile (APP) were performed. The influence of side length and thickness of steel tube, steel ratio and impact velocity on anti-penetration performance were taken into account. Additionally, single-cell square STCC targets were also designed and tested for comparison with the 9-cell grid STCC targets. Damage modes and parameters of the tested targets were measured and discussed. Moreover, the stiffness of radial confinement of grid STCC targets is achieved according to the elastic solution of infinite cylindrical shell in Winkler medium. Furthermore, the penetration resistance and depth of penetration (DOP) for grid STCC targets are obtained on the basis of the dynamic finite spherical cavity-expansion (FSCE) models including radial confinement effect. It is shown that the 9-cell grid STCC targets with optimal dimension match of thickness and side length of steel tube can reduce the DOP by about 17 % and 23 % in comparison with the SIC targets and single-cell square STCC targets, respectively, due to both the confinement of square steel tube to concrete in the impacted cell and the additional confinement of the surrounding cells to the impacted cell; the penetration resistance and DOP of the grid and cellular STCC targets with similar steel ratio is close, and thus the grid STCC targets with simpler manufacturing process and excellent in-plane expandability are preferred in engineering practice; moreover, the predicted results of DOP model based on the FSCE models agree well with the tested results with the maximum disparity less than 12 % and the proposed model is more applicable to the grid and cellular STCC targets with high radial confinement.     

Reaction characteristic of PTFE/Al/Cu/Pb composites and application in shaped charge liner

In this paper, the reaction characteristic and its application in shaped charge warhead of a novel reactive material, which introduced copper (Cu) and plumbum (Pb) into traditional polytetrafluoroethylene/aluminum (PTFE/Al), are studied. The thermal analysis and chemical reaction behavior of the PTFE/Al/Cu/Pb mixture are investigated by Differential Scanning Calorimetry (DSC),Thermo-gravimetry (TG), and X-ray Diffraction (XRD) techniques. Then, the shaped charge liners with PTFE/Al/Cu/Pb reactive materials are fabricated, and the X-ray experiments show that they could form reactive jets with excellent performance under the detonation effects of the shaped charge. Based on that, the penetration experiments of shaped charge with PTFE/Al/Cu/Pb reactive liner against steel plates are carried out, and the results demonstrate that the PTFE/Al/Cu/Pb reactive jets could produce a deeper penetration depth compared to the traditional PTFE/Al reactive jets. Meanwhile, the PTFE/Al/Cu/Pb reactive jets also show significant inner-blast effects, leading to dramatically cracking or fragmentation behavior of the penetrated steel plates. This new PTFE/Al/Cu/Pb reactive liner shaped charge presents enhanced penetration behavior for steel targets that incorporates the penetration capability of a high-density and ductility jet, and the chemical energy release of PTFE-matrix reactive materials.     

提升装备物资采购保障能力的策略设计

装备物资采购关系到装备保障职能的充分发挥和作战效能发挥能力的积累,其采购保障过程涉及极其复杂的技术问题和管理问题。采购保障策略是开展采购和管理项目所确定的思路和实现途径,完善的采购保障策略设计对于重大的装备物资采购项目的成败具有举足轻重的作用。本文从军队装备物资采购的基本内涵与特点入手,结合工作实践和调查研究,从采购信息运用、流程管控、权责修订、法规约束和需求预测等业务管理层面进行分析,阐述了当前装备物资采购的发展现状,提出了提升装备物资采购保障能力的策略设计,以期实现采购组织、流程和系统的整体优化,为装备物资采购改革中相关措施的修订与完善提供新思路和新方法。     

Dynamic parameters of multi-cabin protective structure subjected to low-impact load – Numerical and experimental investigations

The dynamic response of a multi-cabin protective structure subjected to impact load directly affects the protective performance of materials; thus, studying the dynamic response and communication law of wave effect of the load plays an important role in the prediction of protective performance. In this study, the protection experiments of box-structure under air- and/or water-medium are conducted, the dynamic response of the structure subjected to low-impact load is analyzed, and the corresponding numerical simulations are analyzed using the theory of finite element method (FEM). Combined with experimental and FEM simulations, the shock strain distribution, acceleration attenuation, and signal energy in defensive materials are determined. Based on the results, the metal structure exhibits good absorption characteristics for shock vibration. Using the experimental data, we also show that the attenuation of shock wave in water medium should be significantly better than that in air medium, and the protective structure should be designed for a combination of water and air mediums. Meanwhile, the numerical simulation can provide a quantitative analysis process for dynamic analysis of defensive materials.