The dynamics relating the transverse motions of a clamped-free graphite/epoxy beam are investigated. A Bernoulli-Euler beam model with viscoelastic damping is used to predict the transfer function relating the displacement of the clamped end (input) to the displacement of the free end (output). Three different damping strategies are considered. One strategy relies simply on the internal damping arising from the presence of the matrix. A second approach uses continuous strips of a 3M viscoelastic damping material included within the layup to enhance the damping characteristics. And a final design considers optimal placement of the damping material within a specimen to achieve the greatest damping enhancement with a minimum impact on strength, stiffness and weight. Each strategy is applied to two different layup geometries, unidirectional and crossply. An experimental apparatus is configured using a shaker to drive the clamped end and a laser velocity/displacement transducer to measure the displacements of the clamped and free ends. Data are collected and analyzed to evaluate the utility of the model structure for capturing the essential system dynamics and the effectiveness of the damping strategies considered.

Date Published: 1 October 1991
PDF: 13 pages
Proc. SPIE 1489, Structures Sensing and Control, (1 October 1991); doi: 10.1117/12.46602

Published in SPIE Proceedings Vol. 1489:
Structures Sensing and Control
John Breakwell; Vijay K. Varadan, Editor(s)