宇航电子设备中壳体的有限元分析

就宇航电子设备中壳体结构的建模进行了研究，采用板壳单元来描述结构，用局部刚化模拟壳体转角和加强处，并对壳体单元自由度和复要边界条件的处理作了大胆有益的探索。     

基于有限元法的综合支架结构设计与承载能力分析

本文对防爆加热器撬块综合支架的结构进行了分析,找到该支架结构设计上存在的问题并作了相应的改进设计,使得综合支架的结构在满足强度和刚度的同时减轻了整体的重量,在材料的利用上趋于优化的设计; 通过对综合支架的有限元模型施加不同的惯性力,得出不同载荷下综合支架应力变化规律,从而确定出综合支架所能承受的最大惯性力。     

复合材料层合板雷击烧蚀损伤模拟

 为解决复合材料层合板的雷击烧蚀问题,通过复合材料层合板雷电流烧蚀的热-电-结构耦合分析,建立复合材料层合板烧蚀的三维有限元模型。利用删除单元法模拟复合材料层合板在不同脉冲波形雷电流作用下的冲击响应,进行复合材料层合板雷击损伤机理和损伤模式分析,得出了复合材料层合板在不同脉冲波形和峰值雷电流作用下的瞬态热传递和热烧蚀规律。分析了不同雷电流参数对烧蚀结果的影响。结果表明峰值电流、放电量和比能对复合材料层合板的烧蚀尺寸和内部损伤产生很大的影响。     

大长径比固体火箭发动机旋转发射过程中装药结构完整性

以防空导弹大长径比双推力固体火箭发动机装药为研究对象,分析了导弹旋转发射出筒过程中承受的各类载荷。通过计算装药的应力-应变场,发现了装药的危险部位,进而分析了燃烧室发生高压爆炸原因。     

提高机场水泥混凝土道面抗唧泥性能方法研究

唧泥是机场水泥混凝土道面常见病害,会进一步形成脱空病害,影响道面结构承载能力。通过对唧泥的形成机理进行分析,提出了在道面结构设计中提高道面抗唧泥性能的3种措施,分别为提高道面厚度、接缝传荷能力和和基层强度。并采用有限元软件分析了不同措施的工程效果,其中提高接缝传荷能力效果最佳,提高基层强度次之,提高道面厚度效果最差。     

H1 output tracking control for flight control systems with time-varying delay

For flight control systems with time-varying delay, an H1 output tracking controller is proposed. The controller is designed for the discrete-time state-space model of general aircraft to reduce the ef...     

Springback prediction of thick-walled high-strength titanium tube bending

Significant springback occurs after tube rotary-draw-bending （RDB）, especially for a high-strength Ti-3A1-2.5V tube （HSTT） due to its high ratio of yield strength to Young＇s modulus. The combination scheme of explicit and implicit is preferred to predict the springback. This simulation strategy includes several numerical parameters, such as element type, number of elements through thickness （NEL）, element size, etc. However, the influences of these parameters on spring- back prediction accuracy are not fully understood. Thus, taking the geometrical specification 9.525 mm × 0.508 mm ofa HSTT as the objective, the effects of numerical parameters on prediction accuracy and computation efficiency of springback simulation of HSTT RDB are investigated. The simulated springback results are compared with experimental ones. The main results are： （1） solid and continuum-shell elements predict the experimental results well; （2） for C3DSR elements, NEL of at least 3 is required to obtain reliable results and a relative error of 29% can occur as NEL is varied in the range of 1-3; （3） specifying damping factor typically works well in Abaqus/Emplicit simulation of springback and the springback results are sensitive to the magnitude of damping factor. In addition, the explanations of the effect rules are given and a guideline is added.     

H∞ output tracking control for flight control systems with time-varying delay

For flight control systems with time-varying delay, an H∞ output tracking controller is proposed. The controller is designed for the discrete-time state-space model of general aircraft to reduce the effects of uncertainties of the mathematical model, external disturbances, and bounded time-varying delay. It is assumed that the feedback-control loop is closed by the communication network, and the network-based control architecture induces time-delays in the feedback information. Suppose that the time delay has both an upper bound and a lower bound. By using the Lyapu- nov-Krasovskii function and the linear matrix inequality （LMI）, the delay-dependent stability criterion is derived for the time-delay system. Based on the criterion, a state-feedback H∞ output tracking controller for systems with norm-bounded uncertainties and time-varying delay is presented. The control scheme is applied to the high incidence research model （HIRM）, which shows the effectiveness of the proposed approach.     

空间相机结构设计中的拓扑优化及尺寸优化

在复杂的整机力学环境下,以空间遥感相机支架最大自由模态为优化目标,将整机关键技术指标(基频、轻量化要求、自重变形要求等)作为约束条件,利用拓扑优化及尺寸优化技术,对某相机支架进行了优化设计。试验结果表明该方法能有效提高相机基频,相机支架实现了轻量化设计,质量减轻10%,验证了拓扑优化及尺寸优化技术在空间相机结构设计中的有效性。     

微重力下球形贮箱内液体晃动有限元模拟

以卫星球形贮箱为研究对象,用任意拉格朗日-欧拉(ALE)法建立了数学模型,给出了计算的基本方程,并基于MSC-Dytran有限元程序,对常重力和微重力环境中贮箱内推进剂的晃动进行了数值模拟。结果表明,微重力环境中液体更易发生大幅晃动,甚至产生飞溅,工程中常用的等效力学模型已不再适用,而有限元数值模拟方法可较好地解决该问题,为卫星及大充液复杂结构航天器控制系统的设计和分析提供理论参考。