Effects of Method of Loading and Specimen Configuration on Compressive Strength of Graphite/Epoxy Composite Materials.

Abstract

The focus of this investigation was to provide results that will support the selection of a reliable method of compressive testing coupon specimens of filament reinforced polymer matrix composite materials. Three test schemes were examined for testing graphite/epoxy composite material specimens to failure in compression, including an adaptation of the IITRI 'wedge grip' compression fixture, a face-supported-compression fixture, and an end-loaded coupon fixture. The effects of specimen size, specimen support arrangement and method of load transfer on compressive behavior of Gr/Ep were investigated. Compression tests with the modified IITRI and face-supported fixture were conducted on specimens of 12.5-, 25-, and 50-mm widths; of 8-, 16-, and 24-ply thicknesses; and of 0, + OR - 45, and O/+ or - 45/90 fiber orientations. The end-loaded-coupon fixture was used to test 16-ply 0/+ OR - 45/90 specimens. Compressive stress-strain, strength, and modulus data obtained with the three fixtures are presented with evaluations showing the effects of all test parameters, including fiber orientation. The IITRI fixture has the potential to provide good stress/strain data to failure for unidirectional and quasi-isotropic laminates. The face supported fixture was found to be the most desirable for testing + OR - 45sub s laminates. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1980
Accession Number
ADA303089

Entities

People

  • Ronald K. Clark
  • W. B. Lisagor

Organizations

  • Langley Research Center

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Compressive Properties
  • Compressive Strength
  • Epoxy Composites
  • Failure Mode And Effect Analysis
  • Graphitic Materials
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Testing
  • Mechanical Properties
  • Polymer Matrix Composites
  • Stress Strain Relations
  • Stresses
  • Tensile Strength
  • Test Fixtures
  • Test Methods

Fields of Study

  • Materials science

Readers

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