J. Cheng [1]
October 30, 1994
Keywords: fast switching, vibrational damping, vibration control
One of the requirements for the proposed MMA Antenna is the ability to switch rapidly between positions on the sky. This implies large acceleration of the structure and the excitation of various modes of oscillation in the structure is a major concern for any antenna structure. This memo is a brief review of existing damping mechanisms and vibration control methods for large structures. The information on this structure comes from many disciplines : a) structural vibration; b) damping materials; c) vibration control; d) smart material ; e) smart structures and f) optimum control. The damping mechanisms existing include material damping, friction damping, viscoelastic damping, viscous damping, dynamic absorber, tuned mass damping (including rubber spring and magnetic tuned mass damping), piezoelectric damping and proofmass damping. Damping theory and treatment was developed earlier than the 1950's, but practical applications have been very limited until recently. A relatively new field in this area is known as smart structures, a technique involving built in sensors and actuators.
[1] NRAO/Tucson
Last modified: 09 December, 1999
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