THERMAL DEFORMATION COMPENSATION INVESTIGATIONS ON A TYPICAL 1.2M DIAMETER SPACECRAFT REFLECTOR USING INNOVATIVE PIEZO ACTUATED MECHANICALLY ACTIVE BACKUP STRUCTURE
- Paper number
IAC-09.C2.I.4
- Author
Dr. BHAWDEEP SINGH Munjal, Indian Space Research Organization, India
- Coauthor
Mr. ANIL CHAND MATHUR, Indian Space Research Organisation (ISRO), India
- Coauthor
Dr. SHASHI BHUSHAN SHARMA, Indian Space Research Organisation, India
- Year
2009
- Abstract
In this paper, a novel attempt has been made to simplify & study the complex shape displacement issues of parabolic antenna reflectors by using limited number of discreet piezoceramic Bimorph actuators of series and parallel type by introducing the concept of piezo actuated backup structure beams. Finite Element (FE) modeling has been carried out for a 1200 mm diameter parabolic shell surface made up of Polycarbonate material with backup structure of different configurations of backup beams using ATILA, a Finite Element software for modeling structures with smart materials and structural systems. Lab Experiments have been conducted on number of configurations of backup beam combinations to obtain the reflector skin displacements suitable for thermal distortion compensation for a typical INSAT spacecraft reflector. The thermal distortion data for the lab prototype scaled model are obtained using actual IOT (In Orbit Test ) measurements of spacecraft reflector for BOL (Beginning of Life ) & EOL (End of Life cases. When a piezoelectric Bimorph actuator is attached to the beam surface, the converse effects develops a bending moment in the backup structure making the reflector show displacements inward & outward under an electrical field using feed back control loop developed in Labview software. Smart backup concept has been investigated for Polycarbonate as well as Aluminum 6061-T6 materials both. Finite element and experimental results show reasonable correlation where non-linaerities, ageing of piezos and their hysteresis issues have been presently neglected. A real life case study has been taken up in a scaled down model for a INSAT class spacecraft reflector and an approach to compensate the thermal distortions of the spacecraft reflector due to IOT loads by piezo approach has been investigated in this paper which is a hither to fore unexplored domain for Indian GEOSAT missions. This bending of the Polycarbonate reflector skin has potential applications in antenna beam shaping and beam steering in futuristic Reconfigurable antennas and for on-orbit shape correction of INSAT I-2K class satellite antennas.
- Abstract document
- Manuscript document
(absent)