Date of Award

12-1992

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Aeronautics and Astronautics

First Advisor

Peter J. Torvik, PhD

Abstract

This study was an attempt to conceptualize, design, build, and test a constrained layer damping device that uses mechanical advantage for the purpose of increasing the damping of transient vibration of a five-bay planar truss. The aluminum truss was clamped to a fixed support and simulated a solar array. A conventional constrained layer treatment was designed, built, and tested to serve as a benchmark for comparison. For the conventional treatment, Plunkett and Lee's segmented constraining layer technique was used. The improved device, two three-layer sandwich beams spanning the two bays nearest the built-in end, were supported several inches away from the truss plane by a series of levers that were designed to impart a combined shear and bending load to the beam ends. Mindlin and Goodman's method was used to solve a sixth-order, homogeneous differential equation of motion with time-dependent boundary conditions. Experimental results showed that the sandwich beam device did not exceed the loss factors for any of the first four out-of-plane bending modes. However, measurable levels of system damping were achieved for all modes of interest, particularly at the mode whose frequency coincided with that of the sandwich beams.

AFIT Designator

AFIT-GA-ENY-92D-13

DTIC Accession Number

ADA258976

Comments

The author's Vita page is omitted.

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