Experiments in Passive Vibration Reduction
AERONAUTICAL RESEARCH LABS MELBOURNE (AUSTRALIA)
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Damping has been under investigation for many years. A search of the literature reveals an increase in activity in the period from 1960 to 1970. This report sets out the progress in recent years at ARL and evaluates some of the materials that are available in Australia. A number of practical applications are described. Tests were carried out on aluminum plate with dimensions of 600 x 200 x 5mm and 600 x 200 x 6mm. Several identical pieces were cut from the same sheet such that they all had the same lengthwise grain structure. No experiments have been carried out to determine whether there is any difference, in stiffness or damping properties, between pieces of aluminum cut in different directions from the same sheet. The test procedure was in two stages. First, a random input was applied to establish the resonant frequencies of the plate, simply supported on soft foam. In the second stage the plate was excited sinusoidally at the first resonant frequency and a decaying acceleration time history captured on removal of the excitation. Both stages were conducted with and without constraining layers attached to the plate.
- Laminates and Composite Materials
- Marine Engineering