质量块控制自旋导弹的Lyapunov稳定性分析

给出了质量矩控制导弹的动力学模型及在一定条件下的简化动力学模型;用Lyapunov分析方法给出了动稳定性条件。结果说明,推力和静稳定度越大,越有利于动态稳定;阻力越大越不利于动态稳定。     

考虑入口和出口容积效应的涡轮动力学模型

建立了考虑涡轮入口和出口容积效应的涡轮动力学模型 ,利用该模型计算了燃气涡轮气瓶启动的动态响应过程 ,分析了影响涡轮动态特性的主要因素。计算结果表明 :涡轮前容积对涡轮入口压力和出口背压的过渡过程均有显著的影响 ,涡轮后容积对涡轮入口压力的过渡过程影响不大 ,对涡轮出口背压的影响显著。     

初始先验分布未知条件下的DLMR及其Bayes预测

讨论了具有无信息初始先验分布的矩阵变量动态线性模型 (简记为DLMR)及其Bayes预测 ,利用MDIP方法 ,就尺度方差阵∑已知和未知两种情况 ,分别给出模拟初始状态参数(θ1 |D0 )和 (θ1 ,∑ |D0 )的无信息先验分布 ,进而给出其Bayes预测。     

Study on dynamic response of multi-degree-of-freedom explosion vessel system under impact load

In order to study the dynamic response and calculate the axial dynamic coefficient of the monolayer cylindrical explosion vessel, the wall of vessel is simplified as a multi-degree-of-freedom (MDoF) undamped elastic foundation beam. Decoupling the coupled motion equation and using Duhamel's integrals, the solutions in generalized coordinates of the equations under exponentially decaying loads, square wave loads and triangular wave loads are calculated. These solutions are consistent in form with the solutions of single-degree-of-freedom (SDoF) undamped forced vibration simplified model. Based on the model, equivalent MDoF design method (also called MDoF dynamic coefficient method) of cylindrical explosion vessel is proposed. The traditional method can only predict the dynamic coefficient of torus portion around the explosion center, but this method can predict that of the vessel wall at any axial n dividing point position. It is verified that the prediction accuracy of this model is greatly improved compared with the SDoF model by comparing the results of this model with SDoF model and numerical simulation in different working conditions. However, the prediction accuracy decreases as the scaled distance decreases and approaches the end of the vessel, which is related to the accuracy of the empirical formula of the implosion load, the simplification of the explosion load direction, the boundary conditions, and the loading time difference.     

Dynamic modeling and parameter identification of a gun saddle ring

In this study, a theoretical nonlinear dynamic model was established for a saddle ring based on a dynamic force analysis of the launching process and the structure according to contact-impact theory. The ADAMS software was used to build a parameterized dynamic model of the saddle ring. A parameter identification method for the ring was proposed based on the particle swarm optimization algorithm. A loading test was designed and performed several times at different elevation angles. The response histories of the saddle ring with different loads were then obtained. The parameters of the saddle ring dynamic model were identified from statistics generated at a 50° elevation angle to verify the feasibility and accuracy of the proposed method. The actual loading history of the ring at a 70° elevation angle was taken as the model input. The response histories of the ring under these working conditions were obtained through a simulation. The simulation results agreed with the actual response. Thus, the effectiveness and applicability of the proposed dynamic model were verified, and it provides an effective method for modeling saddle rings.     

Determinants of southeast asian military spending in the post-cold war era: a dynamic panel analysis

This study examines the demand of military expenditure among Southeast Asian countries since the end of the Cold War. By using a dynamic panel approach, I find that military spending in the region has been jointly determined by economic, strategic and socio-political factors. In particular, surging foreign debt burdens and the rise of China – two regional issues that gained prominence in the post-Cold War period – show their significance as determinants along with other generalist variables. The results therefore ask for the development of even-handed and region-sensitive approaches to studying military build-up in the region of Southeast Asia.     

舰载机甲板布列调运优化方法研究

通过分析美军现代航空母舰的布列调运方式和发展趋势,发现舰载机的甲板作业调度、停放布列和移动调运是影响舰载机布列调运优化和提高舰载机出动能力的重要方面。针对这些方面的主要特点,采用动态调度方法、空间布局仿真和路径规划方法进行研究能更好地得到布列调运优化效果。据此基本思想,着重从美军航母甲板管理方式、空间布局、路径规划以及甲板作业调度几个方面阐述舰载机布列调运的研究现状,最后对舰载机布列调运优化未来的研究方向进行了展望。     

空间绳网系统展开动力学特性分析

空间绳网系统是一种新型轻质空间柔性结构,具有很大的应用价值。针对地面环境和太空环境下的不同受力特性,推导空间绳网动力学模型;通过地面试验验证仿真模型的可信度;基于展开面积、飞行距离等性能参数,仿真分析空间绳网展开过程中的绳网位形、应力分布以及能量变化等动力学特性,分析轨道高度、捕获方向和发射参数对展开效果的影响。     

基于蚁群算法的无人机航迹规划及其动态仿真

为实现无人机航迹规划的实时性和交互性,建立了无人机动态仿真系统。以"捕食者"无人机模型为应用背景,结合MAK仿真技术的相关理论,利用蚁群算法计算了无人机航迹规划,并实现了Matlab平台下的实例仿真。基于构建的仿真系统,利用MAK软件实现了二维和三维飞行过程的显示,仿真效果理想,为无人机航迹规划结果的交互验证提供了一种有效的手段。     

柔性加工设备机电系统的动力学模型与辨识

在剖析柔性加工设备机电系统结构、信息传递链等基础上，建立柔性加工设备机电系统较精确的动力学模型，并研制相应硬件，实现实时在线模型参数辨识，排除变工况与加工过程的时变性对状态监测与故障诊断的影响，为实现柔性加工环境下多变工况加工过程的实时状态监测、故障诊断与故障预警打下基础。