Time filter

Source Type

Xie C.,Shanghai Key Laboratory of Spacecraft Mechanism
Proceedings of the International Astronautical Congress, IAC | Year: 2013

This paper puts forward a new concept of flexible solar array, which includes lenticular tube, polyimide membrane and triple junction solar cells. Parametric study was performed on a flexible solar array design to identify parameters of interest. The FEA software, ABAQUS, was used to perform the structural analysis to simulate the stiffness of solar array. A full-scale solar array including inertia relief and geometric nonlinearity has been presented. The numerical analysis procedures to introduce pre-stress load into flexible panel were presented firstly, and a rectangle panel was evaluated as a typical example. There are many factors which affect the stiffness of flexible solar array, and they interrelate with each other. Therefore, orthogonal method including four factors, such as membrane's tension, membrane's thickness, lenticular tube's sectional radius and lenticular tube's thickness, has been studiedd in the numerical analysis. Through the Range Analysis of the orthogonal experiment, the main factors affecting the stiffness of solar array have been achieved, and the structural parameters have been optimized. Source

Li B.,Shanghai Key Laboratory of Spacecraft Mechanism | Yang Y.,Shanghai University
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2015

In view of the multiple indexes and their interactive influences evaluating the structure performances of deployable and foldable panel antennas, the structure efficiency is introduced to the deployable structure optimization, and optimization on structure design is studied by the orthogonal experiment for a space deployable truss. The geometric design parameters are analyzed, and an optimal mathematic model is also built with goals of minimum mass and maximal structural stiffness. Aimed at the structure efficiency maximization, the structure optimization for the space deployable truss is calculated, and the design parameters of truss structure are obtained. It is found that the factors that influence structure efficiency such as mass and stiffness are considered synthetically, and the mass of optimized structure is reduced and the deployment stiffness is improved simultaneously. The most important influencing factor on the structure performance is l/w, and the minor influencing factor varies with different optimization goals. When p=90% the study indicates that area has an insignificant effect on the structure efficiency of a space deployable truss. The structure efficiency of the space deployable truss with variable cross-section is better than that of the one with unique cross-section. However, the space deployable truss with unique cross-section shows more economy under unique linkage dimensions.The proposed method can be helpful for the designer in evaluating the structure performances at the conceptual stage of design from the point of system design. © 2015, Press of Chinese Journal of Aeronautics. All right reserved. Source

Li B.,Shanghai Key Laboratory of Spacecraft Mechanism
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2012

Thermal-vacuum tests are performed to evaluate the transmission performance of solid and grease lubricated XB1-60-150 harmonic drive. The effects of ambient temperature, output load, lubrication type, and operation time on the transmission performance of the harmonic drive are investigated based on orthogonal design method for multi-factor analysis, when the transmission efficiency is taken into account as an evaluation index. The transmission performance of the solid and grease lubricated harmonic drivers is studied under a range of temperature and rated load condition. The relationship of transmission efficiency of those to temperature and operation time is analyzed. After running 1.5×10 5 r of the wave generator, the morphologies of the gear teeth and the inner surface of the flexspline under different lubrication type are analyzed by using an optical microscope. It is found that the most important influencing factor on the transmission performance is temperature and the least important influencing factor is operation time. Lubrication type and output load are less important factors. In the temperature range of -40°C to 60°C, the transmission efficiency of grease lubricated harmonic drive is better, however, the solid lubricated harmonic drive shows obviously more stable transmission efficiency. The gear teeth and the inner surface of both the solid and grease lubricated harmonic drivers' flexspline show distinct traces of sliding movement after thermally-cycled test. © 2012 Journal of Mechanical Engineering. Source

Li Y.,Xidian University | Qiu Y.Y.,Xidian University | Peng F.J.,Shanghai Key Laboratory of Spacecraft Mechanism
Applied Mechanics and Materials | Year: 2012

There are some problems in the control for a large flexible spacecraft on orbit such as the coupling, destabilization, and performance of the control system. To solve the problems, an active tuned mass damper (ATMD) is developed utilizing the piezoelectricity smart material, and an optimal output feedback control strategy is proposed based on the positive position feedback (PPF) method. The numerical simulations show that the developed ATMD/PPF method can suppress the flexible structural vibration induced by disturbances effectively. Using the method, the stability of the control system can be ensured and a good performance can be maintained even in case that the ATMD is in failure. © (2012) Trans Tech Publications. Source

Huang Y.,Shanghai JiaoTong University | Ouyang Q.,Shanghai JiaoTong University | Zhang D.,Shanghai JiaoTong University | Zhu J.,Shanghai Composites Science and Technique Co. | And 2 more authors.
Acta Metallurgica Sinica (English Letters) | Year: 2014

Carbon materials, including carbon fibers, graphite, diamond, carbon foams, carbon nanotubes, and graphene, are attractive reinforcements for aluminum matrix composites due to their excellent mechanical and/or physical properties as well as light weight. Carbon materials reinforced aluminum (C/Al) composites are promising materials in many areas such as aerospace, thermal management, and automobile. However, there are still some challenging problems that need to be resolved, such as interfacial reactions, low wettability, and anisotropic properties. These problems have limited the use of these composites. This review mainly focuses on the categories, fabrication processes, existing problems and solutions, coatings and interfaces, challenges and opportunities of C/Al composites so as to provide a useful reference for future research. © The Chinese Society for Metals and Springer-Verlag 2014. Source

Discover hidden collaborations