双曲线圆截面建筑结构雷诺数效应模拟实践

在流线型结构气动性能风洞试验研究中,结构表面绕流特征雷诺数效应的准确模拟对于确定风荷载、评价其气动性能的影响是决定性的.通过改变模型表面粗糙度可以实现原型结构超高雷诺数条件(Re≥10~7)绕流效应模拟,但模拟手段及效果受人为经验因素影响较大,难于总结表面粗糙度与绕流形态变化关系,给实际模拟操作造成不便.设计两组双曲线圆截面结构模型风洞试验,通过在模型表面粘贴不同厚度粗糙纸带的办法,尝试并实现了模型超高雷诺数条件绕流特征模拟,分析了粗糙度及试验风速对模型表面绕流压力分布、截面阻力系数等参数的影响,初步总结了相对粗糙度随模型尺度的变化规律,为更好展开圆截面建筑结构气动性能研究提供了借鉴.     

真空热试验测控仪器驱动器通用化设计

航天器真空热试验中温度的测量和外热流的模拟使用到多种不同型号的测控仪器, 这些仪器驱动方式也大不相同,这给测控系统应用软件的开发带来很多不便。文章基于VISA（虚拟仪器软件结构）标准针对目前使用的各种仪器编写了通用的驱动函数,并以动态链接库的形式进行封装,可以供调用进行二次开发,有利于仪器驱动配置过程的简化和测控软件的通用化设计。     

航天器编队飞行和空间演示验证技术——有人照料空间实验室与平动-转动物理仿真器

航天器编队飞行是近年来国内外航天领域研究的热点问题,同时也是空间技术今后一个重要发展方向。为此文章首先讨论航天器编队飞行特点;其次研究编队飞行今后能否获得顺利成功应用,有关它的各种算法和软件空间飞行演示验证技术和方法;最后介绍了美国麻省理工学院空间系统实验室（MITSSL）对航天器编队飞行算法软件空间演示验证的方法和实验。     

RESEARCH ON DIGITAL ACTIVEFLUTTER SUPPRESSION

ＲＥＳＥＡＲＣＨＯＮＤＩＧＩＴＡＬＡＣＴＩＶＥＦＬＵＴＴＥＲＳＵＰＰＲＥＳＳＩＯＮＺｏｕＣｏｎｇｑｉｎｇ，ＣｈｅｎＧｕｉｂｉｎ（５－ｔｈＤｅｐａｒｔｍｅｎｔ，ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕｔｉｃｓａｎｄＡｓｔｒｏｎａｕｔｉｃｓ，...     

红外加热笼覆盖系数对热流均匀性的影响研究

通过设定红外加热笼与卫星表面之间不同距离,改变加热笼的覆盖系数,仿真模拟了卫星表面到达热流的分布,研究了加热笼的覆盖系数对卫星表面到达热流密度均匀性的影响,分析结果表明：当加热笼距离卫星表面100mm以上,选取覆盖系数大于0．06的加热笼,即可满足到达卫星表面热流的均匀性要求。     

空间紫外辐射环境及效应研究

空间紫外辐照度虽然很低（只有约118.1 W/m2）,但是由于单个紫外光子的能量很高,可以使大多数材料分子的化学键断裂,所以紫外辐射会对航天器外露材料的性能产生严重影响。紫外辐射可以导致航天器的热控涂层光学性质改变,使有机聚合物材料发生降解,光学、力学性能降低。文章介绍了空间紫外辐射环境的模型,列举了对航天器常用的有机粘合剂、柔性材料、有机薄膜等的紫外辐射效应,并对空间紫外辐射效应的深入研究提出建议。     

Impact of aperture on dynamic response of sandwich plates with aluminium face-sheets and PMI core based on an alternative finite element formulation and experiments

Apertures generally exist in the sandwich structures attributing to mechanical connection and lightweight, which might induce failure of such structures. Thus, it is required to realize the impact of aperture on mechanical behaviors of sandwich structures. If transverse shear deformations are unable to be described accurately, the reasonable prediction of dynamic behaviors of the form-core sandwich plates with apertures will meet severe challenges due to a large difference of transverse shear mo...     

Preload relaxation analysis and reliable life prediction of space connection and separation device based on accelerated degradation tests

The safety and reliability of space connection and separation device has become a key issue due to the increasing service span of deep space exploration mission. The long-term preload relaxation (a key failure mode) of connection and separation devices is focused in this paper. A series of tests have been designed and implemented to investigate the preload relaxation regulation and a comprehensive method has been constructed to analyze and predict the reliable lifetime of the device. The two-stage preload relaxation law of the device is found and reasonably considered. Due to the different relaxation mechanism, the first-stage preload relaxation is assessed based on the working-condition test results, and the second-stage preload relaxation is characterized by accelerated test results. Finally, the service reliability and reliable life are evaluated. The experiment and assessment results demonstrate the reasonability and effectiveness of the proposed method which can achieve long-service reliability analysis for space connection and separation device within limited time.     

天基快速响应体系的虚拟演示系统

为了实时监测天基快速响应体系的工作过程,开发实现了一套基于 OSG平台的虚拟演示系统。首先,对组成天基快速响应体系的天基平台、轨道运载器和有效载荷进行三维可视化建模,并设计了定制在轨服务任务和管理天基平台的图形交互接口；其次,基于典型的轨道转移模型,介绍了执行任务的天基平台选定方法和流程；最后,通过典型的信息保障任务,展示了基于 OSG的天基快速响应体系的虚拟演示系统。     

Influence and experiment of cable-net manufacturing errors on surface accuracy of mesh reflector antennas

Cable-net structures are of substantial importance in the construction of large mesh reflector antennas. Owing to the inevitable errors in their manufacturing process, the reflector surface accuracy deteriorates. This study makes a comprehensive investigation of random manufacturing errors during constructing the mesh reflector antennas, and analyze its influence on reflector surface accuracy. Firstly, the sensitivity of reflector surface accuracy with respect to the random errors of the unstressed cable length is mathematically deducted. Secondly, a non-button connecting method is proposed and analyzed to reduce manufacturing errors. Thirdly, two physical experiment models based on 2.62-meter mesh reflector antenna are made. Finally, numerical examples and experimental tests are given to demonstrate the effectiveness of the proposed method. Compared with the traditional method, the proposed method can effectively reduce the influence of the manufacturing errors on the reflector surface accuracy. Moreover, the reduction in the sizes of the nodes also reduces the risk of entanglement of the mesh reflector antenna during the deployment process, and thereby improves the deployment reliability.