Polar Woven Flywheel Resin Film Infiltrated

This Small Business Innovation Research (SBIR) project will develop a low-cost resin film infusion approach to fabricating a polar woven (hoop and radial direction reinforced), lightweight composite material rotor for flywheel energy storage (FES) systems. The application of this device will be for an integrated replacement of chemical batteries and attitude control actuators in spacecraft. The tasks of design, fabrication, and testing of a FES advanced rotor design for energy storage with combined attitude control system (ACS) involves many challenges. High priority design issues are long term durability (fatigue life), dynamic stability (balance), and fail-safe operation. Foremost, long-term durability must be adequately accommodated, failure to do so will lead to dynamic on-board disturbances (self-emitted vibrations) and non-safe operating conditions. During an anticipated ten year service, a Low Earth Orbit (LEO) communication satellite is expected to undergo 50,000 cycles (charge/discharge) while supplying 3 to 5 kW-hr of usable energy. The depth-of-discharge of a mechanical (flywheel) energy storage is up towards 90%. Such a high number of cycles and depth-of-discharge presents a major concern for fatigue failure, especially due to radial stresses where the stress and strain capability of a composite material is limited. A polar woven architecture offers radial stiffness and strength support to the rotor design compared to a uni-directional all-hoop winding architecture.