Pretension And Structure Optimum Design For Cable-mesh Deployable Antenna

Cable-mesh deployable antenna with flexible cablenet system is utilized widely inradar, reconnaissance, earth observation and deep space exploration for its light weightand small stowed volume. Based on existing results achieved by deployable antennaresearch team of Xidian University, the problems like cable pretension design forcable-beam structure, optimum design for pretension and structure of cable-meshdeployable antenna are discussed in this paper.A structural division method that can help to improve efficiency of pretensiondesign for cable-beam structure is proposed. In this method, a cable-beam structure isdivided into inner cablenet structure and edge cablenet-beam structure. The pretensionequilibrium conditions of these two parts are studied by non-linear finite elementmethod, and based on this, division condition and division principle of the structuraldivision method is deduced in theory.Because inner cablenet is a pure cablenet structure with given shape and topology,balance matrix analysis method is used to help obtain the best pretension distribution ofinner cablenet with the uniformity as objective.For edge cablenet-beam structure, with obtaining equilibrium force of innercablenet’s pretension as goal, non-linear finite element method combined with balancematrix analysis method is used for pretension compensation iterative adjustment of edgecablenet that is affected by beam’s displacement. Because edge cablenet-beam structurehas less cable elements than overall structure, its non-linear finite element iterativecalculations are easier to be implemented, and its stiffness matrix is easier to be workout also.In order to obtain optimal antenna structure with ideal cable system shape andpreset pretension distributions, an iterative optimum structural design method based oncablenet system iterative adjustment method described above is proposed here. Themathematical model of optimization selects minimum weight of structure as objective,and antenna’s shape accuracy as constraint. By combining cablenet system iterativeadjustment method to solve above mathematical model, the shape accuracy of antennacablenet system and beam can meet the constraint requirements at the same time, andthe antenna structure with both optimal weight and ideal cablenet system shape can alsobe obtained at last.The present method and design software is applied to the development of a2m cable-mesh deployable antenna model, and the results of model experiments show thatthe present method is valid and correct. Also, the method and software is used toinstruct the development of a17m axi-symmetric reflector antenna experimentalprototype and a10m offset parabolic reflector antenna experimental prototype, and thepractical application results are satisfying as well.