Structural Design And Prototype Development Of Spaceborne Shaped Parabolic Truss Cable-net Deployable Antenna

With the rapid development of space technology,higher and higher requirements are put forward for space antennas,which are mainly reflected in four aspects: large diameter,high precision,light weight,and high storage ratio.In this regard,scientific and technical personnel have carried out long-term exploration and proposed various schemes successively.Large-scale truss cable-net deployable antenna is a promising design scheme.This paper takes this as the main attack direction,and applies it to the problems encountered in the spaceborne antenna,makes a more in-depth exploration,and makes a prototype to verify it,which undoubtedly has important theoretical significance and engineering promotion and application value.The main work contents are as follows:1.A truss cable-net deployable antenna truss design method and a new lower cable-net configuration design scheme based on the layered iterative method are proposed.Firstly,the topology of the antenna is determined according to the shape of the antenna aperture,and the calculation formula of the module rib length that meets the requirements of the antenna aperture is deduced.Secondly,a layered iterative method is proposed to calculate the key node positions of the supporting truss to ensure good splicing between modules.At the same time,it has strong expansibility;then,the initial configuration design of the cable net under the antenna is carried out,which solves the problems that the rear cable net surface is too flat and the cable force is too large due to the low height of the strut;finally,the establishment of The overall geometric model of the frame-cable-net antenna is presented.2.The form-finding design of the truss cable-net deployable antenna has been completed.Firstly,the constant tension design of the inner cable segment is carried out according to the principle of force density,and on this basis,the boundary cable force is optimized according to the minimum norm method,and finally the pure cable net shape design of the cable net structure is realized;The influence of the accuracy of the antenna surface,the system balance equation of the cable-net-truss composite structure and the nonlinear optimization model with the force density as the design variable are established based on the finite element theory and the principle of the force density method;finally,by introducing the sensitivity of the force density The matrix transforms the nonlinear optimization problem into a sequence quadratic programming problem to solve,and realizes the iso-tension shape design of the cable-net-truss composite structure.3.The on-orbit structure-thermal comprehensive analysis of the spaceborne truss cable-net deployable antenna was completed.Firstly,the finite element model of thermal analysis is established,and the temperature field distribution of the antenna entering and leaving the shadow area is solved based on the specific orbit;then,the temperature field is applied to the finite element model in the form of load,and the temperature field generated by the antenna under the action of temperature load is calculated.The thermal-induced deformation is analyzed;finally,the possible thermal-induced vibration of the antenna when the antenna enters and exits the shadow area is analyzed.4.The principle prototype of the truss cable-net deployable antenna is processed.First,the detailed design of the key joints of the antenna support truss and the cutting and networking of the cable net are carried out;then,the ground deployment experiment of the principle prototype is carried out to verify the correctness of the antenna structure design and the effectiveness of the design of the key joints of the truss;The shape and surface accuracy of the principle prototype is photogrammetrically measured and adjusted to ensure that the principle prototype has a good shape and surface accuracy.