Abstract: A singly or doubly encapsulated actuator/sensor package in which a ceramic actuator/sensor (10) may be first encapsulated in a primary encapsulating material (12) and is encapsulated in a fiber-reinforced composite material (20, 22). A combination of the material and ply angles (&thgr;) of the fiber-reinforced composite material (20, 22) are used to control selection of a composite coefficient of thermal expansion (CTE) and the stiffness or compliance of the package with respect to a selected axis. By optimal selection of the material and the ply angle, based upon a suitable actuation strength figure of merit, a CTE of zero or a CTE matching that of an underlying structural member (24) is obtained, while simultaneously maximizing the actuation strength in a selected actuation direction.

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Abstract: A motion control apparatus is provided for controlling oscillations of an appendage 10 coupled to a spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the appendage 10 and the appendage base 14. A plurality of motion control elements 28 are interposed between the appendage base 14 and the spacecraft 12 and/or along the guidelines 20 between the appendage base 14 and the remote portions 22 of the appendage 10 or both. The motion control elements 28 include visco-elastic fluid, electro-rheological fluid, magnetic-rheological fluid, or a piezo-electric stack so that a motion control property of the motion control elements 28 may be varied according to the magnitude of an electric or magnetic field source 30 coupled thereto.

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.