Improvement and Optimization of Internal Damping in Fiber Reinforced Composite Materials

Abstract

The objective of this research were to study the effects of such parameters as fiber aspect ratio, fiber orientation and fiber/matrix properties on damping in fiber reinforced polymer composites. These objectives were to be met by using both experimental and analytical approaches. The development of improved techniques for fabrication and testing of specimens and the development of relatively simple design equations for prediction of damping were desirable goals which were also met. Two new computer-aided testing techniques based on the impulse frequency response approach were developed. Specimens of graphite/ epoxy, boron/epoxy and Kevlar aramid/epoxy were fabricated by using an autoclave-style press cure which was developed specifically for this program. Although a number of parameters were studied, the emphasis was on the influence of fiber length, fiber orientation and fiber material on damping of polymer composites. The experimental results show that, as predicted, very low fiber aspect ratios are required to produce significant improvements in damping. Of the three fiber types tested, the Kevlar aramid fiber composite was found to have much better damping than graphite or boron fiber composites. Measurements and predictions also indicate that the control of fiber orientation in a continuous fiber reinforced laminate may be a better approach to the improvement of damping than the control of fiber aspect ratio.

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Document Details

Document Type
Technical Report
Publication Date
Mar 03, 1986
Accession Number
ADA168576

Entities

People

  • R. F. Gibson
  • S. A. Suarez

Organizations

  • University of Idaho

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Composite Materials
  • Fiber Reinforced Composites
  • Fiber Reinforced Polymers
  • Laminates
  • Material Degradation Processes
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Engineering
  • Mechanics
  • Micromechanics
  • Polymer Matrix Composites
  • Resonant Frequency

Fields of Study

  • Materials science

Readers

  • Reinforced Composite Materials