Shape Memory Alloys for Vibration Isolation and Damping of Large-Scale Space Structures.

摘要

The US Air Force is currently pursuing large sparse aperture arrays with low-frequency structural design requirements to ensure that thermal and gravity gradient induced on-orbit disturbances do not excite the structure. Structures with these frequency response characteristics will need a larger error budget for active control due to their limitations to passively accommodate external excitations and meet their performance requirements. This work will investigate utilization of Shape Memory Alloys (SMAs) to enhance the passive structural stability of the structure, by taking advantage of the SMA capacity for large, recoverable deformations and hysteretic response. SMAs can be pre-strained up to their transformation region and can act as constant force structural elements, in which loading variations will result in hysteretic damping due to phase transformation. Current use of SMAs as vibration isolation and damping devices is limited to small deformations and a constrained environment. Large space structures provide an opportunity to exploit the full potential of SMAs, while providing feasible technical solutions to a reliable design of such systems.