弹炮结合武器效能仿真的毁伤模型

针对弹炮结合武器和所拦截空中目标的特点,探讨建立弹炮结合武器仿真的毁伤模型.分析了目标的轨迹特点,建立了空间杀伤区的表示模型,针对不同的俯冲攻击倾角,分别建立了详细的拦截纵深模型,最后给出了导弹和高炮武器分系统的可拦截次数模型.该模型能较精确地对毁伤效能进行仿真.     

抗滑短桩与桩周土共同作用的探讨

根据某工程的应力监测结果和ANSYS计算结果,就抗滑短桩与桩周土共同作用进行探讨,得出了两点认识：第一,考虑桩土接触带贡献作用和桩-土共同工作是更趋于实际情况的,也是更经济合理的;考虑比不考虑桩土接触带的贡献,作用在抗滑短桩上的剩余水平下滑力约小10%。第二,接触带采用合适的弹性模量和厚度进行计算的结果与监测结果相当接近(相差≯5%)。     

一种改进的变异粒子群算法研究

粒子群优化算法PSO(Partic le Swarm Optim ization)是一类性能优越的寻优算法。但由于早熟问题,影响了算法性能的发挥。针对这一问题,引入粒子距离的概念,提出一种新的PSO改进方法(称为NA-PSO)。通过求解组网雷达的系统偏差,表明了NA-PSO算法的可行性,与对比方法相比较,能有效配准,且具有更好的收敛精度和更快的进化速度。     

防空目标分配中雷达遮蔽区问题研究

目标分配是防空指挥控制的主要任务,而目标相对于防空导弹火力单元的遮蔽判断是目标分配必须考虑的重要因素。分析了目标遮蔽区的判断条件,推导出目标在遮蔽区飞行时间的计算方法,提出了一种快速表示遮蔽区域图的离散处理方法,并研究了考虑目标遮蔽区影响的目标分配问题。通过实例计算,验证了目标遮蔽计算判断和分配方法的合理性,研究结果对实时指挥控制有应用价值。     

鱼雷攻击占位相关参数计算

讨论了鱼雷攻击占位机动过程中,最小占位速度和最短占位时间的计算问题,采用数值计算分析方法,得出了各种不同敌我初始态势和相对运动速度下对应最短占位时间的占位点的分布规律,推导出最小占位速度和最短占位时间的计算公式。     

非均匀焊接接头的力学建模与断裂分析

建立了非均匀焊接接头"4区连接"的新模型,并利用积分变换-奇异积分方程的方法,研究了焊缝区的反平面断裂问题。数值计算表明:增大界面区的刚度或者适当地增大焊缝区、热影响区和界面区的宽度都有利于降低焊缝区裂纹的应力强度因子;相对于高匹配情形而言,低匹配焊接接头焊缝区的抗断裂能力明显较高。     

舰舰协同防空的舰空导弹杀伤区分析

针对舰艇编队协同防空时的耦合杀伤区形状及纵深等问题进行了研究,以定量地对编队耦合杀伤区进行简化描述。分析了单舰对典型目标的杀伤区特性,探讨了舰艇编队的典型防空队形,研究了纵向上递阶多层次、横向上同阶耦合的"递阶封闭圈原理"。以一阶耦合杀伤区为重点,依据攻击目标的不同,将其分成相对航路捷径为零和相对航路捷径均非零两类情况建立了耦合杀伤区纵深的计算模型,并扩展到了高阶耦合的情况。研究了耦合杀伤区与舰舰间距和来袭目标进攻舷角等参数的相互关系以及灵敏度。结果表明建立的模型符合实际,具有一定的指导意义。     

火灾区域模拟原理及CFAST软件应用

分析火灾区域模型的理论基础 ,介绍CFAST软件的功能及操作 ,并应用该软件对某建筑物二楼舞厅的火灾安全性进行评估     

Effects of nano-sized aluminum on detonation characteristics and metal acceleration for RDX-based aluminized explosive

Nano-sized aluminum(Nano-Al)powders hold promise in enhancing the total energy of explosives and the metal acceleration ability at the same time.However,the near-detonation zone effects of reaction between Nano-Al with detonation products remain unclear.In this study,the overall reaction process of 170 nm Al with RDX explosive and its effect on detonation characteristics,detonation reaction zone,and the metal acceleration ability were comprehensively investigated through a variety of experiments such as the detonation velocity test,detonation pressure test,explosive/window interface velocity test and confined plate push test using high-resolution laser interferometry.Lithium fluoride(LiF),which has an inert behavior during the explosion,was used as a control to compare the contribution of the reaction of aluminum.A thermochemical approach that took into account the reactivity of aluminum and ensuing detonation products was adopted to calculate the additional energy release by afterburn.Combining the numerical simulations based on the calculated afterburn energy and experimental results,the param-eters in the detonation equation of state describing the Nano-Al reaction characteristics were calibrated.This study found that when the 170 nm Al content is from 0％to 15％,every 5％increase of aluminum resulted in about a 1.3％decrease in detonation velocity.Manganin pressure gauge measurement showed no significant enhancement in detonation pressure.The detonation reaction time and reaction zone length of RDX/Al/wax/80/15/5 explosive is 64 ns and 0.47 mm,which is respectively 14％and 8％higher than that of RDX/wax/95/5 explosive(57 ns and 0.39 mm).Explosive/window interface velocity curves show that 170 nm Al mainly reacted with the RDX detonation products after the detonation front.For the recording time of about 10 μs throughout the plate push test duration,the maximum plate velocity and plate acceleration time accelerated by RDX/Al/wax/80/15/5 explosive is 12％and 2.9 μs higher than that of RDX/LiF/wax/80/15/5,respectively,indicating that the aluminum reaction energy significantly increased the metal acceleration time and ability of the explosive.Numerical simulations with JWLM explosive equation of state show that when the detonation products expanded to 2 times the initial volume,over 80％of the aluminum had reacted,implying very high reactivity.These results are significant in attaining a clear understanding of the reaction mechanism of Nano-Al in the development of aluminized explosives.     

序列近似优化方法及其在火箭外形快速设计中的应用

针对序列近似优化方法在代理模型构造与采样策略等方面的不足,基于采样点局部密度,引入与局部密度成反比的样本点影响体积概念,通过优化总影响体积确定径向基函数最优核宽度,满足序列近似优化过程不同规模、非均匀样本条件下的函数近似需要;建立潜在可行域最大距离加点准则,并与潜在最优加点准则结合平衡算法的探索能力与开发能力;建立三步收敛判定准则;构建改进序列近似优化的算法流程。对于Golinski减速器的优化设计问题,算法在目标函数调用42次后便搜索到全局最优解,体现了其良好的全局寻优能力与搜索效率。以"天航二号"火箭为例,建立其外形优化问题数学模型,所提优化方法在调用原始计算模型165次之后便搜索到全局最优解,大大提高了设计效率,同时飞行试验也表明设计结果满足要求。