Prestressed Back-up Structure Optimization Of Fully Movable Radio Telescope

Radio telescope is playing an important role in Chang'e project(lunar exploration project),manned space project,China space station plan and Beidou navigation system.Astronomical observation and data transmission are also inseparable from radio telescope.Therefore,large-diameter radio telescope is of great significance to the rapid development of radio astronomy and the exploration of the universe.With the rapid development of radio astronomy,researchers have higher and higher requirements for the aperture and accuracy of radio telescopes.For this reason,China will build a 110 m caliber giant radio telescope in Qitai County,Xinjiang Autonomous Region,which will become the most powerful single aperture ground-based fully movable radio telescope in the world.In this paper,the optimization of the prestressed back-up structure of the 110 m caliber ground movable radio telescope is taken as the research object,and the improvement of the accuracy of the main reflecting surface and the reduction of the self weight of the telescope are taken as the optimization indexes.The specific research contents are as follows:(1)This paper introduces the traditional layout of the back-up structure of the fully movable radio telescope,and introduces the prestressed cable into the back-up structure,and puts forward three cable arrangement schemes.From the concept of prestress,the rationality of the scheme of prestressed back-up structure in reducing the structure weight is explained.This paper analyzes three kinds of stress states of prestressed back-up structure,and corrects the coordinate of reflection surface without self weight of back-up structure.The optimization design flow of radio telescope structure is established to provide theoretical guarantee for the follow-up research.(2)Genetic algorithm is applied to the optimization of prestressed back-up structure of radio telescope.The operation parameters of genetic algorithm are explained in detail.The genetic algorithm is applied to the design optimization of prestressed back-up structure.This paper analyzes the feasibility of genetic algorithm in the optimization of the back-up structure of a large-diameter radio telescope,and makes a comparative study of the pure bar system and prestressed back-up structure of a 12 m diameter radio telescope by using genetic algorithm.(3)By using the finite element simulation analysis method and genetic algorithm,the whole model of the 110 m caliber ground movable radio telescope is established.The optimization design of the prestressed back-up structure design scheme and the pure bar structure design scheme is carried out.The effectiveness of the prestressed cable for reducing the self weight of the back-up structure and improving the accuracy of the reflecting surface is analyzed.(4)This paper analyzes the natural vibration characteristics of the prestressed backup scheme of the 110 m caliber ground movable radio telescope.In this paper,the finite element method is used to analyze the seismic response of the radio telescope under the action of frequent earthquake,the combination of frequent earthquake and static load,and the action of rare earthquake.The safety performance of the prestressed back-up structure of radio telescope is evaluated.