Strength Degradation of Aramid-Fiber/Epoxy Composites

Abstract

The moisture absorption kinetics for Kevlar 49 epoxy have been measured for four environmental conditions. The strength degradation for the composite has been systematically measured by six experiments for each of the four states. The tensor polynomial strength coefficients are generalized to represent the strength degradation for the moisture absorbed states. Due to the big difference between tensile and compressive strength for Kevlar 49 composites, analytical representation of the failure surface requires a third- order tensor polynomial. Four additional biaxial experiments are needed to provide the necessary data. The degree of fiber-controlled strength degradation is different from the degradation of matrix-controlled strength, which causes the failure surface to shift and deform. This shift should also be characterized by a third-order tensor polynomial.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1980
Accession Number
ADA085670

Entities

People

  • Edward M. Wu

Organizations

  • University of Washington

Tags

Communities of Interest

  • Biomedical
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Aramid Fibers
  • Composite Materials
  • Compressive Strength
  • Engineering
  • Epoxy Composites
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Military Research
  • Moisture Content
  • Plastic Explosives
  • Test Methods

Readers

  • Linear Algebra
  • Mechanical Engineering/Mechanics of Materials.
  • Reinforced Composite Materials