Structural Design,Analysis And Optimization Of A Cable-net Antenna Double-loop Truss

The development of the aerospace industry is the result of the rapid progress of science and technology and the rapid development of social production.It has a wide and far-reaching impact on politics,economy,military and people’s social life.In recent years,more and more advanced spacecraft have been sent to space one after another.They maintain contact with the ground through the on-board antennas carried on them to realize communication,reconnaissance and navigation between space and the ground.The structure size of the spaceborne antenna has a decisive influence on its own performance.The large-diameter spaceborne antenna can realize long-distance transmission of electromagnetic signals,precise positioning of detection targets and capture of weak electromagnetic signals.As a type of spaceborne antenna,the annular truss deployable antenna has the advantages of high storage rate,high precision,and the quality does not multiply with the increase of the antenna diameter.It is expected to develop in the direction of the development of super-large aperture spaceborne antennas in space.This thesis firstly introduces a kind of traditional single-ring deployable truss structure serving on-orbit abroad,and describes a new type of double-ring deployable truss structure based on the improvement of the traditional single-ring structure,which has the advantages of high storage ratio and high rigidity;Then,the folded size of the new double-ring deployable truss structure is analyzed,and the overall size planning is carried out according to the target diameter and focal length of the deployable antenna,and the side length and unfolded height of the double-ring deployable truss structure are determined.Dimensional analysis and deployment dimension design,complete the design of the main components of the truss structure,and then complete the complete machine design of the double-ring deployable truss structure.According to the changing method of the space coordinate system,the spatial position of the new double-ring deployable truss structure is studied,and the velocity equation and acceleration equation of the nodes during the unfolding process of the truss structure are obtained;The deployable antenna scheme is feasible;adjust the reflector surface accuracy of the cable net of the deployable antenna,and repeat the deployment test,and it is found that the accuracy error of the reflector surface after each deployment is very low,which verifies the stability of the double-loop deployable antenna.The quality of the existing double-ring deployable truss structure is evaluated,and by comparing with other cable-net deployable antennas,it is proved that the double-ring deployable truss structure has a large mass under the same diameter and needs to be lightweighted.The stiffness of the double-ring deployable truss structure has been obtained,and the load analysis of the parts with a large mass proportion is carried out,and the guidance on the lightweight of the structure is given.Then,by changing the structural form,reducing the structural size and removing the unloaded structure The lightweight structure is completed;finally,the feasibility of the lightweight structure is verified by checking the stiffness and strength of the lightweight structure.