Finite Element Micromechanical Analysis of a Unidirectional Composite Including Longitudinal Shear Loading.

Abstract

A microscopic region of a unidirectional composite is modeled by a finite element micromechanical analysis using a generalized plane strain formulation, but including longitudinal shear loading. The analysis is capable of treating elastic, transversely isotropic fiber materials, as well as isotropic, elastoplastic matrix materials. Matrix material properties are considered to be temperature- and/or moisture-dependent. A special Gaussian elimination procedure is modified for the present treatment. Stresses are calculated for each element and appropriate failure criteria invoked. First-element failure is the limit of the present analysis. Other possible forms of results are: unidirectional composite properties, overall composite stress-strain response, and various plots of internal stress contours. The longitudinal shear loading capability permits the analysis of shear response of unidirectional composites in the fiber direction. Solid rod torsion test data used to obtain experimental verification indicate good agreement with the theoretical predictions for glass/epoxy and graphite/epoxy at various temperature and moisture conditions. In conjunction with a laminated plate point stress analysis, the present micromechanical analysis has been used to predict the stress-strain response into the inelastic range of a graphite/epoxy (+ or - 45)4s laminate. Available experimental data for various environmental conditions indicate excellent agreement with the analytical predictions. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1981
Accession Number
ADA097811

Entities

People

  • David A. Crane
  • Donald F. Adams

Organizations

  • University of Wyoming

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Climate Change
  • Composite Materials
  • Computer Programs
  • Crystal Structure
  • Elastic Properties
  • Failure Mode And Effect Analysis
  • Laminates
  • Materials
  • Materials Science
  • Materials Testing
  • Mechanical Engineering
  • Mechanics
  • Metal Matrix Composites
  • Micromechanics
  • Modulus Of Elasticity
  • Shear Modulus
  • Stress Strain Relations

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.