Response of an Alumina Fiber Reinforced Aluminum Composite to Combined Tension-Torsion

Abstract

The introduction of fiber reinforced composites in structural design has generated the need to develop new test procedures for rating these materials. The assessment of the performance of such composites under combined tensile-torsional loading should increase their reliability. Specimens such as the cruciform, the thin wall cylinder, and the center cracked plate have been used extensively to investigate the response of isotropic materials to biaxial loading. These specimens, however, may not be appropriate for all types of fiber reinforced composites. It has been shown that, in certain composites, premature failure by fiber debonding can occur at points of stress concentration or where there is a change in the specimen's contours. Because of these trends, the cruciform and the center cracked plate could be poor candidates for combined tensile-torsional testing of fiber reinforced composites. On the other hand, the thin wall cylindrical specimen could be promising for certain applications (e.g. pressure vessels). Aluminum coupons reinforced unidirectionally with continuous alumina fibers were loaded in combined tension-torsion. Experimental results indicated that the superimposition of a 0.0025 shear strain reduced the tensile strain to failure by 67%. Similarly, the superimposition of a 0.0007 tensile strain reduced the shear strain to failure by 81%.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1991
Accession Number
ADA239560

Entities

People

  • Gary P. Pelletier
  • Marc S. Pepi
  • Nikos Tsangarakis

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Composite Materials
  • Eccentricity
  • Engineering
  • Fiber Reinforced Composites
  • Materials
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Working
  • Military Research
  • Shear Stresses
  • Stress Concentration
  • Stress Strain Relations
  • Stresses
  • Tensile Strength
  • Thin Walls

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Reinforced Composite Materials
  • Structural Dynamics.