Abstract
The spacecraft antenna reflector orbiting in the space environment would be exposed to continuous variation in both temperature level and temperature distribution because of the variation of solar radiation and shadowing conditions (temperature varies from −80 to 180 °C). The thermally induced structural responses would occur with the variations of the on-orbit thermal loads. Thermal induced deformation could adversely affect the performance of antenna reflector. The thermally induced deformation can be controlled using lead-based piezoelectric actuator. In the last few decades, these lead-based piezoelectric ceramics are used abundantly due to their superior performance. However, these lead-based piezoelectric ceramics are toxic in nature and cause severe health and environmental problems during its fabrication. In this study, thermally induced deformations in the antenna reflector are controlled using lead-free piezoelectric ceramics. Finite element formulation of layered composite antenna reflector has been presented to predict the deformation. Further beam shaping and beam steering of the antenna reflector through the piezoelectric actuator has been demonstrated. Finally active shape control of antenna reflector has been demonstrated by optimising the size and location of piezoelectric patches and the applied electric potential.
Acknowledgement
Rahul Vaish acknowledges DST, New Delhi, India for financial support through INSPIRE Faculty Award-2011.