Determination of Natural Frequency for CFRP Composite Satellite Antenna Reflector using Vibration Analysis

The reflector is required for high gain space antenna systems for telecommunication payloads. The carbon fibre reinforced polymer (CFRP) is extensively used in space and aero-space application due to their good specific properties over conventional metals and alloys. The frequency for a typical satellite antenna reflector is important parameter for different types of payloads.    In this paper, CFRP reflectors have been manufactured using autoclave curing process to achieve high dimensional accuracy. Four layers of CFRP prepreg have been laid at various orientation on stainless steel AISI 430 paraboloid mould. The assembly of mould and prepreg along with consolidation material has been vacuumed and cured in autoclave machine. The high volume fraction can be achieved using autoclave process in composite manufacturing. The natural frequency has been determined for reflector using FFT analyser in vibration measurement test setup. The volume fraction has been determined using scanning electron microscopic (SEM) technique. The effect of layup orientation and fiber volume fraction on natural frequency has been studied. As volume fraction increases, the natural frequency for reflector decreases gradually.