Abstract
The increasing demand for large antenna systems in space, providing a higher gain over a concentrated area, has led to research into deployable antenna systems due to the volume restraints imposed by currently available launch modules. A new 5. 0m aperture diameter deployable skeletal antenna system, incorporating spring loaded joints and carbon fibre/epoxy structural members manufactured by the pullwinding technique has been conceived. An engineering model of the deployable system has been manufactured and analysed experimentally and numerically. The prototype antenna was shown to offer significant advantages over previously developed skeletal systems in terms of fewer structural components and mechanical devices translating to reduced manufacturing costs and increased deployment reliability. Experimental analyses undertaken for the manufactured prototype exhibited a non-linear dynamic response due to dimensional clearances in the energy loaded joints. The structure was linearised, thereby providing a more deterministic response, using an improved joint design which removed the possibility of any dimensional clearances in the joints. Representative numerical models of the prototype antenna were successfully constructed and verified by comparison with the numerically predicted and experimentally measured natural frequencies and modes of vibration. These validated numerical models were used to model the energy supplied by the mechanical joints, to verify the deployment sequence of the antenna, to predict the stresses induced in antenna systems when the joints lock into their deployed configurations and finally to examine the dynamic response of the structure after deployment. Deployment tests, using helium balloons and roller supports to simulate a zero gravity environment, validated the numerically predicted deployment sequence and proved the design concept.