临界剪切应力系数曲线适用性研究

曲板的屈曲问题与材料的弹性模量和泊松比有关,对于机身蒙皮材料2060-T8E30,曲板临界剪切应力系数曲线的适用性有待研究。基于Abaqus的线性静力分析中的Buckle算法,以机身蒙皮材料2060-T8E30建立了多种构型曲板,对比有限元分析值和曲板临界剪切应力系数曲线,通过分析误差,得出结论:对于2060-T8E30材料,可以认为d/h=1.5的ks(曲板临界剪切应力系数)曲线相比有限元分析值偏高,误差不大于15%;d/h=2的ks曲线相比有限元分析值偏高,误差不大于20%;d/h=3.5的ks曲线相比有限元分析值偏高,误差不大于35%。在飞机机身结构常用的参数,即d/h=3.5,Z≤20的情况下,当Z10时,ks曲线的适用性较好,误差不大于10%;当10Z≤20时,ks曲线相比有限元分析值偏高,误差不大于20%。     

T800碳纤维增强复合材料加筋壁板压缩稳定性试验及工程计算方法验证

国内对T800碳纤维复合材料结构的研究刚刚起步,需要对其加筋壁板的稳定性进行系统地研究.通过改变蒙皮厚度、筋条间距、筋条几何参数等设计8种构型的试验件,进行压缩稳定性试验;考虑侧边边界条件及蒙皮有效宽度的影响,对两种常用的压缩屈曲载荷工程计算方法进行验证.结果表明:在相同筋条面积下,筋条惯性矩提高屈曲载荷增大,加筋壁板的破坏载荷主要取决于壁板的横截面积;蒙皮厚度和筋条间距对屈曲载荷的影响大于对破坏载荷的影响;对于薄蒙皮,当侧边简支且蒙皮有效宽度b=D-b2/2时,计算值与试验值最为接近;对于厚蒙皮,当侧边简支且蒙皮有效宽度b=D时,计算值与试验值最为接近.     

北斗长河组合导航伪时差测量与ASF修正

通过时间比对手段把长河二号和北斗一号两个导航系统的原子钟组成一个参考时间尺度,测量导航信号由天线发出时刻相对于同一参考时间尺度的时差改正数,通过卫星微波或地面长波信号把改正数发送给用户接收机,经解调解码,就可以进行北斗长河组合导航的伪时差测量,从而解算接收机的位置和钟差。用模式计算和实测相结合的方法解决长河信号的传播的ASF改正问题,是提高组合导航定位准确度的有效手段。     

推桨式察打无人机起落架总体布置参数设计研究

现有飞机起落架总体布置参数设计的规范和要求主要适用于传统战斗机,如果按此规范和要求设计推桨式察打一体无人机起落架将带来诸多问题。从推桨式察打一体无人机的布局和飞行特点入手,通过对起落架总体布置参数的定义和内涵进行分析,提出一种适合推桨式察打无人机起落架总体参数和总体布置的设计方案,对察打一体无人机起降特点进行分析;对比“捕食者B”无人机起落架总体布置参数,验证本文设计方案的有效性。结果表明：擦地角可减小,建议不小于6°（静态,含间隙）;防倒立角可减小,建议11°～12°（静态）;停机角范围可适当减小,建议-2°～-1°;起落架总体布置方案可选择机身式、较长的外八字形起落架布置型式。     

某飞机机翼壁板战伤的胶接修理计算

为了准确模拟损伤部位的局部位移和力边界条件,基于某飞机的全杌有限元模型,对机翼整体壁板高应力区的圆孔型损伤,采用不同搭接宽度计算了受损壁板的胶接修理.研究了飞机机翼壁板不同损伤尺寸下搭接宽度与残余强度的关系,给出了飞机满足使用要求前提下的受损壁板胶接修理所需要的搭接宽度.这些结论为整体壁板的胶接修理提供参考.     

基于电容感测高温隔离触控模块的研制

电容式感测是一种低功耗、低成本且高分辨率的非接触式感测技术，适用于接近检测、手势识别和远程液位感测等。采用FDC2214电容式传感技术检测触控按键，有效去除干扰。将检测值通过IIC总线传送给MSP430单片机，使用自适应算法处理数据以确定某个物体是否在目标感应区域内，最远感应距离可达30cm。在工厂应用中可用厚玻璃窗实现对恶劣环境的隔离，人机交互时无需进入高温、灰尘、油渍等恶劣环境就可实现操控，保证了安全性并节省了成本。     

Integrated supersonic wind tunnel nozzle

In supersonic wind tunnels, the airflow at the exit of a convergent-divergent nozzle is affected by the connection between the nozzle and test section, because the connection is a source of disturbance for supersonic flow and the source of disturbance generated by this disturbance propagates downstream. In order to avoid the disturbance, the test can only be carried out in the rhombus area. However, for the supersonic nozzle, the rhombus region is small, limiting the size and attitude angle of the test model. An integrated supersonic nozzle is a nozzle and a test section as a whole, which is designed to weaken or eliminate the disturbance. The inviscid contour of the supersonic nozzle is based on the method of characteristics. A new curve is formed by the smooth connection between the inviscid contour and test section, and the boundary layer is corrected for the overall curve. Integrated supersonic nozzles with Mach number 1.5 and 2 are designed, which are based on this method. The flow field is validated by numerical and experimental results. The results of the study highlight the importance of the connection about the nozzle outlet and test section. They clearly show that the wave system does not exist at the exit of the supersonic nozzle, and the flow field is uniform throughout the test section.     

Integrated method of guidance,control and morphing for hypersonic morphing vehicle in glide phase

The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations, but the design of guidance and control system with morphing laws remained to be explored. An Integrated of Guidance, Control and Morphing (IGCM) method for Hypersonic Morphing Vehicle (HMV) was developed in this paper. The IGCM method contributed to an effective solution of morphing characteristic to improve flight performance and reject the disturbance for guidance and control system caused by the morphing system for HMV in gliding phase. The IGCM models were established based on the motion models and aerodynamic models of the variable span vehicle. Then the IGCM method was designed by adaptive block dynamic surface back-stepping method with stability proof. The parallel controlled simulations’ results showed the effectiveness in accomplishing the flight mission of IGCM method in glide phase with smaller terminal errors. The velocity loss of HMV was reduced by 32.8% which inferred less flight time and larger terminal flight velocity than invariable span vehicle. Under the condition of large deviations of aerodynamic parameters and atmospheric density, the robustness of IGCM method with variable span was verified.     

火箭上升段滚动时域制导控制一体化设计

针对传统火箭上升段制导与姿态控制系统分离设计无法最大程度优化控制精度、控制量需求等系统整体控制性能的问题，提出一种基于凸优化的滚动时域制导控制一体化(IGC)设计方法。首先建立反映质心运动和绕质心运动耦合关系的IGC模型并对其进行反馈线性化获得面向控制的线性模型。然后考虑控制约束，将上升段IGC问题建模为最优控制问题，基于凸优化理论设计滚动时域控制器。该方法基于滚动时域控制(RHC)策略中反馈校正和滚动优化的思想，可以及时弥补模型误差和外部干扰等造成的不确定性；同时利用凸优化算法计算复杂度低、求解简单的优势，有效解决了含控制约束的复杂优化问题的求解。基于李雅普诺夫稳定性理论证明了闭环系统的稳定性。数值仿真校验了该滚动时域控制方法的有效性和鲁棒性；并且仿真结果表明，火箭上升段IGC设计比传统分离设计制导精度更高、控制量需求更小且姿态变化更加平缓。     

航天测控资源应用现状及综合利用研究

针对我国航天测控资源存在“条块分割、设备分散”等问题,进行相应分析并提出解决设想,其目的是找到适合我国国情的航天测控资源合理配置,实现测控资源和空间资源充分共享及综合利用。首先对我国地球同步卫星和近地卫星的航天测控资源应用现状进行分析;其次根据不同卫星的测控特点,提出航天测控资源综合利用的设想,并对其利弊进行了详细讨论;最后结合我国航天测控资源实际情况,指出了实现航天测控资源综合利用需要重点解决测控覆盖范围等关键技术问题。