Characterization of the Dynamic Response of Thick Composite Structures.

Abstract

The objective for this research remains at contributing to the understanding of the fundamental mechanisms which determine the response of thick composite structures to time dependent loading. The following specific objectives were originally proposed and, with some modification, continue to form the basis for the research plan: (1) Postulate the primary micromechanical attributes in the range of relatively small strain which are expected to directly affect frequencies, mode shapes, participation factors, and response magnitude. Such attributes will include material system, fiber density, ply thickness, cross ply geometry, strain rate sensitivity, accumulated damage, manufacturing imperfections, and others. (2) Choose a specific fixed free beam geometry and considering both glass/thermoset and graphite/epoxy material systems, determine dependencies of fundamental modal quantities upon micromechanical attributes determined in 1 above. Develop predictive techniques using the ABAQUS FEM code. (3) Determine candidate damage mechanisms and resulting shifts in modal variables for subject material systems under time dependent loading. (4) Characterize the currently existing knowledge base concerning micromechanical effects on modes of vibration of composite structures. The work will build upon previous effort and is directed toward specifically categorizing behavior which would then contribute to optimum design of thick composites for high strain rate shock loading. (5) Document the results in media compatible with sponsor's Mechanics of Composites Program overall objectives and guidelines.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1997
Accession Number
ADA326161

Entities

Organizations

  • University of Maine

Tags

DTIC Thesaurus Topics

  • Composite Materials
  • Composite Structures
  • Computational Modeling
  • Dynamic Response
  • Fabrication
  • Frequency
  • Geometry
  • Graphitic Materials
  • Materials
  • Materials Processing
  • Materials Science
  • Mechanical Engineering
  • Orientation (Direction)
  • Resonant Frequency
  • Strain Rate
  • Thermosetting Plastics
  • Vibration

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Reinforced Composite Materials
  • Theoretical Analysis.