Optimization of 110 m Aperture Fully Steerable Radio Telescope Prestressed Back Frame Structure Based on a Genetic Algorithm

Radio telescopes play an important role in lunar exploration projects, manned space flight projects, and navigation systems. China is constructing a giant 110 m aperture ground-based fully steerable radio telescope in Qitai County, Xinjiang Uygur Autonomous Region. In this paper, a 110 m aperture fully steerable radio telescope prestressed back frame structure is proposed and optimized to improve the reflector accuracy and to reduce the weight of the telescope. First, prestressed cables are introduced into the back frame structure, and three innovative cable layout schemes are presented. Second, for stress state analysis, the wind pressure distribution on the main reflector is explored using wind tunnel experiments. Third, some improvements in genetic algorithms for addressing computational complexity are explained. Finally, the effects of prestressed cables on the weight reduction and reflector accuracy improvement are analysed. Additionally, in order to evaluate the safety of the prestressed back frame structure, its strength has been checked, and the internal force and displacement under static conditions and in earthquakes are interpreted in detail.

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A European look at the future of manned space flight

10.2514/6.1977-339 ◽

1977 ◽

Author(s):

R. GIBSON

Keyword(s):

Space Flight ◽

Manned Space Flight ◽

The Future ◽

Manned Space

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Artificial gravity for long duration manned space flight

10.2514/6.1994-4666 ◽

1994 ◽

Author(s):

E. Hoegenauer ◽

K. Wagner

Keyword(s):

Space Flight ◽

Artificial Gravity ◽

Manned Space Flight ◽

Long Duration ◽

Manned Space

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4th Manned Space Flight Meeting

10.2514/mmsfm65 ◽

1965 ◽

Keyword(s):

Space Flight ◽

Manned Space Flight ◽

Manned Space

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Biomedical problems of EVA support during manned space flight to Mars

Acta Astronautica ◽

10.1016/j.actaastro.2008.11.015 ◽

2009 ◽

Vol 64 (7-8) ◽

pp. 682-687 ◽

Cited By ~ 7

Author(s):

Vladimir P. Katuntsev ◽

Yuri Yu. Osipov ◽

Sergey N. Filipenkov

Keyword(s):

Space Flight ◽

Manned Space Flight ◽

Manned Space

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Experimental Research and Finite Element Analysis on Behavior of Steel Frame with Semi-Rigid Connections

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.168-170.553 ◽

2010 ◽

Vol 168-170 ◽

pp. 553-558

Author(s):

Feng Xia Li ◽

Bu Xin

Keyword(s):

Architectural Design ◽

Plastic Hinge ◽

Steel Frames ◽

Seismic Energy ◽

Internal Force ◽

Steel Frame ◽

Frame Structure ◽

Element Analysis ◽

Rigid Deformation ◽

Steel Frame Structure

Most steel beam-column connections actually show semi-rigid deformation behavior that can contribute substantially to overall displacements of the structure and to the distribution of member forces. Steel frame structure with semi-rigid connections are becoming more and more popular due to their many advantages such as the better satisfaction with the flexible architectural design, low inclusive cost and environmental protect as well. So it is very necessary that studying the behavior of those steel frame under cyclic reversal loading. On the basics of connections experiments the experiment research on the lateral resistance system of steel frame structure has been completed. Two one-second scale, one-bay, two-story steel frames with semi-rigid connections under cyclic reversal loading. The seismic behavior of the steel frames with semi-rigid connections, including the failure pattern, occurrence order of plastic hinge, hysteretic property and energy dissipation, etc, was investigated in this paper. Some conclusions were obtained that by employing top-mounted and two web angles connections, the higher distortion occurred in the frames, and the internal force distributing of beams and columns was changed, and the ductility and the absorbs seismic energy capability of steel frames can be improved effectively.

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A SIMULATION SYSTEM FOR THE MANNED SPACE-FLIGHT GROUND-SUPPORT NETWORK

10.2514/6.1963-1816 ◽

1963 ◽

Author(s):

L. RUETZ ◽

ARMISTEAD DENNETT

Keyword(s):

Space Flight ◽

Simulation System ◽

Support Network ◽

Ground Support ◽

Manned Space Flight ◽

Manned Space

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Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

Research in Astronomy and Astrophysics ◽

10.1088/1674-4527/21/11/293 ◽

2021 ◽

Vol 21 (11) ◽

pp. 293

Author(s):

Shan-Xiang Wei ◽

De-Qing Kong ◽

Qi-Ming Wang

Keyword(s):

Temperature Field ◽

Temperature Distribution ◽

Solar Radiation ◽

Radio Telescope ◽

Thermal Imaging ◽

Uniform Temperature ◽

Large Radio Telescope ◽

Uniform Temperature Distribution ◽

Uniform Temperature Field ◽

Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

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