| Deployable antenna structures are the essential aerospace equipment to tracking and data relay, space communications, electronic reconnaissance satellites. With the development of aerospace science and technology, deployable antenna structures have an urgent demand in large scale, light weight, high precision and so on. Cable-rib tensioned deployable antenna combines the characteristic of tensegrity deployable mechanism and traditional hinged deployable mechanism, it has advantages of simple structure, light quality, simple control and high stiffness. Taking cable-rib tensioned deployable antenna structure as the research object,the deployable antenna deployment principles and kinematic characteristic, the cable arrangement and stability analysis, dynamic characteristics analysis, structural optimization and design have been studied in this paper. The details are as follows:Based on the features of ribbed deployable antenna and tensegrity antenna, a cable-rib tensioned deployable antenna structure is proposed. The structural composition and deployable principle are analyzed in detail. Though analyzing advantages and disadvantages of the styles of deployable antenna structure, the best one has been established and the kinematic model has been established. Kinematic characteristic on this model is analyzeed by MATLAB in this paper. which can provide a theoretical basis for structural design of deployable antenna structure and the cables arrangement.The cable arrangement and stability analysis have been studied in this paper. Based on kinematic model, the distance of two endpoint of cables are computed, by analyzing change regularity, different change type cables are classified. The cables which increase power supply and movement interference are removed. The cables initial arrangement is proposed by considering the structural symmetry. On this basis, based on truss structure stability judgement method, the balance equation is extended to the beam and cable element.the antenna structure stability analysis geometric model is established by simplifying this structure. After analysis, the cable-rib tensioned deployable antenna structure is statically indeterminate, kinematical determinate structure, there is no rigid-body motions, it is the geometrical stability.After the deployment and locked, the whole antenna mechanism is stiffened as a stable structure, it consists the beam and cable element. Mechanical properties are complicated,belong to rigid flexible coupling system. The finite element model of the cable-rib tensioned deployable antenna structure is built by using APDL. The modal analysis and harmonic response analysis of this structure are carried out, and the natural frequencies and corresponding vibration modes of structure are obtained. Though considering the structural symmetry, stress state, stability, inherent frequency, the best cables arrangement has been established. The harmonic response analysis is carried out by modal superposition method,the correctness of modal analysis is verified. Finally, the influence of structure parameters and material performance on natural frequency of structure is studied, and the method to improve the natural frequency is proposed,which can provide a theoretical reference for structural geometric parameters choice.The BP neural network predictive model has been established, by taking the mass and the first order natural frequency as the objective functions, and taking the structural geometric parameters as design variations. This model optimization analysis is performed by genetic algorithm, and the design parameters of this supporting structure are established.In accordance with the relevant geometric parameters, combining with ADAMS analyzing, the deployable supporting structure and the driving mechanism are designed in this paper. |
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