Mechanical Properties And Model Selection Analysis Of FAST Cable-Lifting System

Five-hundred-meter aperture spherical telescope(FAST)was built up in Guizhou province of China.It is the caliber biggest and strongest detecting ability of single diameter radio telescope.FAST consists of about 4450 reflector unit,the installation scheme of reflectors need to be completed by two cable-shifting systems.When the half span cable cranes and the full span cable crane.Installation of reflector is completed,the two half span cable cranes will be changed into a full span cable crane to maintain the telescope.The cable hoisting construction method is widely used in many large construction projects.In order to optimize the linetype and type selection of hoisting cables,and in order to ensure the best mechanical performance and the best linear section of the cable during the operation,the cable force and the section area of the cable should be calculated accurately.Based on a series of statics theory and the analysis of ANSYS finite element software,the cable system is up to the ideal state:(1)The flexible cable bearing system is a cable or chain as the main load-bearing components,with tower crane as a support,in accordance with different structural requirements,combined with different functional parts to meet the use requirements.Through studying the equipment and characteristics of hoisting system,and comparing the six kinds of cable hoisting methods,such as double car ropeway method and track center method,the cable lifting scheme of FAST is determined;(2)Based on the influence of wind load and temperature strain on the precision of FAST structure,the working accuracy of the cable hoisting system of FAST is determined.Through the analysis of ANSYS finite element software,the maximum deflection of the suspension cable under maximum working load conditions and the maximum stress risk section of the cable line are found.The linear dynamic performance of the cables in the case of the load is discussed;(3)In the theory of the theory of hyperbolic functions,the theory of catenary and the parabolic theory with algebraic function are common in the theory of hyperbolic functions.Catenary function is transcendental function,it discussed the mechanical problems can be quantified for each perpendicular to the line in mechanical problems,and parabola theory calculations are based on parallel to the line of mechanical problems,often in a parabolic function instead of a super function and a quantitative research.In this paper,based on the parabola theory,radiant and full span cable hoisting system system has carried on the detailed analysis of the static,it is concluded that the maximum deflection of two system,line selection and safe working conditions.In view of the defects of the FAST reflector unit lifting span,like complex terrain,interference characteristics,high position,conventional equipment can not be used.The cable system uses radiation type,full span type two system,considering the effect of wind load,equipment weight,construction load conditions,the cable system security the working conditions and the selection results,for the lifting system and other large span flexible cable structure provides a part of the safety construction conditions of exact solutions and reference conditions.