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Title
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Characterization of Viscoelastic Damping in an Antenna Structure
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Description
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The dynamics of a ribbed antenna structure are examined. The symmetry of the structure generates repeated natural frequencies and hence a "beating" phenomena in the dynamic response of the structure. Two of the antenna's ribs are replaced with passively damped ribs which are treated with a constrained viscoelastic material. Since these repeated natural frequencies cannot be identified using standard frequency domain techniques, a time domain method, the Eigensystem Realization Algorithm (ERA), is employed to measure damping in the repeated and closely spaced natural frequencies. A comparison is made between ERA and the Polyreference identified modal parameters. Consideration is given to a slight structural modification to increase the interaction between the damped and undamped antenna ribs, thereby increasing the overall performance of the viscoelastic damping in each mode.
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Creator
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Argento, James
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Carlin, Robert
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Garcia, Ephrahim
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Publisher
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Wright-Patterson Air Force Base, OH : Wright Laboratory, Flight Dynamics Directorate, Air Force Systems Command
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Date
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1991
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Format
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1 online resource (14 pages) : ill.
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Type
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article
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Abstract
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The dynamics of a ribbed antenna structure are examined. The symmetry of the structure generates repeated natural frequencies and hence a "beating" phenomena in the dynamic response of the structure. Two of the antenna's ribs are replaced with passively damped ribs which are treated with a constrained viscoelastic material. Since these repeated natural frequencies cannot be identified using standard frequency domain techniques, a time domain method, the Eigensystem Realization Algorithm (ERA), is employed to measure damping in the repeated and closely spaced natural frequencies. A comparison is made between ERA and the Polyreference identified modal parameters. Consideration is given to a slight structural modification to increase the interaction between the damped and undamped antenna ribs, thereby increasing the overall performance of the viscoelastic damping in each mode.
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Date Issued
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1991-08
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Extent
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14
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Corporate Author
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State University of New York at Buffalo
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Laboratory
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Wright Laboratory
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Report Number
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WL-TR-91-3078 Volume II, pages EDF-1 to EDF-14
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DoD Project
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2401
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DoD Task
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240104
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Distribution Conflict
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No
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Index Abstract
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Contrails only
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Photo Quality
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Not Needed
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Report Availability
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Full text available
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Provenance
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University of Colorado Colorado Springs, Kraemer Family Library
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Identifier
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ADA241312
