陆军战术作战仿真想定生成方法

针对作战仿真中想定数据的生成需求,在分析仿真想定内容的基础上,规范了仿真想定的生成流程,给出了指挥规则的抽取和量化方式,提出了面向实体的仿真想定结构化表示方法和基于XML的仿真想定存储结构,分析了利用G IS和3D技术实现作战计划和行动协同规划的方法途径,探讨了仿真想定数据的校核内容和重用机制,为实现仿真想定生成工具提供了一种有效的思路。     

远程迷惑式干扰效果评估模型

在分析远程迷惑式干扰机理的基础上,研究迷惑式干扰的各种影响因素,分别引入了箔条云相似因子、时间有效性因子、编队模拟逼真度因子、雷达识别影响因子和战术选择影响因子等多个效果评估指标,提出了多箔条云数目的整合模型,然后求导出在远程迷惑式干扰务件下搜索雷达对真实目标的捕捉概率计算模型,最后验证了模型的合理性.     

基于排放和模糊神经网络模型的柴油机故障诊断方法

根据排放检测数据规律,定义并提取特征参数,建立了规则与模糊神经网络有机结合的柴油机故障诊断模型及其对应的特征知识库,确立了模型的“可塑性”学习路线,并以单缸失火故障为例,进行了模型诊断实例研究。结果表明：运用该方法进行柴油机的故障诊断,结果准确,识别速度快,诊断效率高。     

数据挖掘故障诊断专家系统

为了及时准确地对防空导弹飞行试验故障进行诊断,克服传统专家系统获取专家知识的瓶颈,立足于防空导弹飞行试验历史数据,利用数据挖掘的方法获得飞行试验故障模式判定决策树,进而得出导弹故障判定规则,形成故障诊断专家知识库,构建防空导弹故障诊断专家系统.这使数据挖掘和专家系统两者的优点得到充分发挥.     

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.     

Damage mechanics and energy absorption capabilities of naturalfiber reinforced elastomeric based bio composite for sacrificial structural applications

The present study deals with the experimental, finite element (FE) and analytical assessment of low ballistic impact response of proposedflexible'green' composite make use of naturally available jute and rubber as the constituents of the composite with stacking sequences namely jute/rubber/jute (JRJ), jute/rubber/rubber/jute (JRRJ) and jute/rubber/jute/rubber/jute (JRJRJ). Ballistic impact tests were carried out by firing a conical projectile using a gas gun apparatus at lower range of ballistic impact regime. The ballistic impact response of the proposed flexible composites are assesses based on energy absorption and damage mechanism. Results revealed that inclusion of natural rubber aids in better energy ab-sorption and mitigating the failure of the proposed composite. Among the three different stacking se-quences of flexible composites considered, JRJRJ provides better ballistic performance compared to its counterparts. The damage study reveals that the main mechanism of failure involved in flexible com-posites is matrix tearing as opposed to matrix cracking in stiff composites indicating that the proposedflexible composites are free from catastrophic failure. Results obtained from experimental, FE and analytical approach pertaining to energy absorption and damage mechanism agree well with each other. The proposed flexible composites due to their exhibited energy absorption capabilities and damage mechanism are best suited as claddings for structural application subjected to impact with an aim of protecting the main structural component from being failed catastrophically.     

Investigate the effects of magnetic fields on the penetration ability of a shaped charge jet at different standoffs

The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490, 650 and 800 mm. The experimental results without and with the magnetic field are compared in terms of the shaped charge jet form, stability and penetration ability. A theoretical model based on one-dimension fluid dynamics is then developed to assess the depth of penetration of the shaped charge at those three standoffs and magnetic conditions. The results show that the penetration capability can be enhanced in more than 70% by the magnetic field. The theoretical calculations are compared with the experimental results with reasonably good correlation. In addition, the parameters introduced in the theory are discussed together with the experiments at three standoffs studied.     

基于时域平均的齿轮故障诊断

提出了信号时域平均处理的新算法,解决了周期截断误差对平均结果的影响,并对测取的齿轮箱齿轮故障振动信号进行了处理。实验结果表明:该方法在齿轮故障信号的处理中能够消除背景噪声的影响,取得比较理想的效果。     

某供弹机构现存问题动力学分析及参数优化探讨

介绍了环形杠杆供弹机构的工作原理及其在实际使用中常见的问题,建立了机构的动力学模型,对模型进行动态求解,模拟了机构的工作过程。借助求解结果,针对问题产生的原因进行了动力学分析,在理论上找到了问题产生的根源。在此基础上建立了机构的最优化数学模型,给出了优化方案,最后对优化方案和现有结构进行了比较。     

粗糙神经网络的航空电子系统故障诊断方法

提出了一种基于粗糙神经网络的航空电子系统故障诊断方法.该方法运用粗糙集理论进行知识规则的提取,用提取的规则对航空电子系统输出数据进行分类,再用神经网络对每一类进行辨识,最后用粗糙集分类结果与各个神经网络输出进行综合得到系统一步预测结果,将该预测结果与航空电子系统实际输出进行阀值比较,进而进行故障诊断.实际应用表明该方法可行并能够有效地检测系统故障,故障诊断率高.