Profile Accuracy Analysis Of Tri-directional Cable Net Antenna Structures

The cable-net structure is widely used in radar, reconnaissance, earth observation, deep space exploration and other fields,for it has the characters of light weight,high folding rate and high unfolding accuracy. Three-orientation cable-net antenna structure is a kind of the cable-net structures and has the advantages of high profile precision, mechanical property and good ability to keep the shape. Hoop Truss Deployable Structure is a kind of the deployable structure, and has the characters of light weight, simple structure and so on. It is suitable to support the cable-net structure. The research in the paper includes design for the hoop truss deployable structure and the cable net structures, and precision and instability analysis of three-orientation cable-net antenna structures. The concrete content is as following:Firstly, the Hoop Truss Deployable Structure was designed and analyzed. Hoop truss is the structural support of three-orientation cable-net antenna structure, and has a major influence on the profile accuracy. The deploy principle for the deployable antenna outer truss structure is analyzed. The driving method for the truss, its unit number and folding rate are researched. The model for the truss structure is manufactured according to the determined parameters.Secondly, the net surface forming of the three-orientation cable-net antenna structure is completed on zero state,and the influence of gravity and precision is ignored. The structural parameters state is initial conditions of the profile accuracy analysis on zero state. The length for the string is analyzed by analyzing the principle error. The number of mesh segmentation is researched by optimizing the net surface tension ratio and cable network quality. According to the above parameters, the finite element model is established with ANSYS.Thirdly, the precision and profile accuracy analysis of the three-orientation cable-net antenna structures is completed on initial state. Specifically through the establishment of equilibrium matrix, the finite element model is determined. Based on the work above, the pretension distribution is determined with a method of tension optimization, the pretension non-uniform coefficient as the objective function. Then a shape-state for the whole antenna structure is generated by considering the influence for the cable structure with hoop truss, and an optimization example for the shape-state is given.Finally, the net working environment is bad, in order to analysis stability of string-net structure when local failure appears, based on the dynamic relaxation method analyses cable net structure instability. Through the results of the analysis, the local unreasonable structures of the cable-net structures were adjusted.