An Analysis of Cracks Emanating From a Circular Hole in Unidirectional Fiber Reinforced Composites. Part 2.

Abstract

An analytical method is developed for cracks emanating from a circular hole in an off-axis unidirectional fiber-reinforced composite. The method is formulated by using conservation laws of elasticity and fundamental relationships in anisotropic fracture mechanics. The method provides a very convenient and accurate means to examine the complicated crack behavior, when used in conjunction with a suitable numerical scheme such as the finite element method. The formulation is eventually reduced to a system of linear algebraic equations of mixed-mode stress intensity factors. Fracture parameters, describing crack-tip of deformation and fracture in the composite, are obtained explicitly. Effects of material anisotropy and crack/hole geometry are examined also. Of particular interest are the energy release rates associated with crack extension; their values are evaluated for various cases. Results show that mixed-mode stress intensity factors and energy release rates associated with the cracks emanating from a hole change very appreciably with fiber orientation in the composite. K sub I and G increase monotonically with increasing e; but K11 reaches its maximum at theta = 45 deg, and then decreases gradually as theta increases further. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1981
Accession Number
ADA302677

Entities

People

  • J. F. Yau
  • S. S. Wang

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aeronautics
  • Air Force
  • Aircrafts
  • Applied Mechanics
  • Composite Materials
  • Elastic Properties
  • Epoxy Composites
  • Fiber Reinforced Composites
  • Finite Element Analysis
  • Fracture (Mechanics)
  • J Integrals
  • Jet Propulsion
  • Materials
  • Materials Laboratories
  • Mechanics
  • Navy
  • Three Dimensional

Readers

  • Calculus or Mathematical Analysis
  • Materials Science (Mechanical Engineering).
  • Reinforced Composite Materials