Development of a Damping Device for Large Reflector Antennas

Abstract

Reflector antennas are exposed to large mechanical loads during launch originating from vibrations propagating through the satellite and from sound pressure. Customers of RUAG Space, a leading supplier of reflector antennas, are demanding larger and larger antennas of the analysed type, but due to the high surface to mass ratio, the antennas are highly affected by the loads. This master's thesis aims to develop a damping device, decreasing the mechanical vibrations by applying appropriate damping materials at applicable locations of the antenna. A reflector antenna from RUAG Space is analysed by means of FEM, including models of three passive damping device propositions. For material selection, screening is carried out with material indices for damping and several space materials databases, implementing technical material requirements set up by customers and space industry. A damping device utilizing vibration isolation by elastomeric layers at the interfaces between the reflector antenna and the satellite is the recommended solution. Two materials from the screened groups, uoroelastomers, per uoroelastomers and silicone rubbers, are applied for the proposed device and they show significant damping in the temperature and frequency range considered. Fluoroelastomers are suitable as device materials due to their favourable mechanical properties and a glass temperature appropriate for the application.