The Relationship Between Fractal Geometry and Fractography

Abstract

Fractal geometry has been used to describe irregular fracture surfaces in a quantitative way. The fractal dimensional increment has been related to the fracture toughness of the material through the elastic modulus and a characteristic structure parameter, ao. The study of fractography has shown the relationship between the flaw to mirror size ratio and the fracture toughness. An experimental observation has shown that the fracture toughness is related to the elastic modulus through another structure parameter, bo. Combining all of these relationships leads to the conclusion that the fractal dimensional increment, D*, is directly related to the flaw-to-mirror size ratio. This note shows that experimental measurements of the fractal dimension and the flaw-to-mirror size ratio on glasses, a glass ceramic, polycrystalline ceramics and a single crystal all agree with the prediction. The implication of this finding is that there is a linear scaling law in operation at fracture between the energy of crack initiation and branching and is reflected in the features on the fracture surface.

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Document Details

Document Type
Technical Report
Publication Date
Aug 28, 1991
Accession Number
ADA240835

Entities

People

  • J. J. Mecholsky Jr.
  • S. W. Freiman

Organizations

  • University of Florida

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Biomaterials
  • Ceramic Materials
  • Cracks
  • Crystallography
  • Engineered Materials
  • Engineering
  • Fractography
  • Fracture (Mechanics)
  • Geometry
  • Materials
  • Materials Engineering
  • Materials Science
  • Measurement
  • Mechanics
  • Military Research
  • Stress Intensity Factors
  • Universities

Readers

  • Structural Health Monitoring of Composite Structures.
  • Theoretical Analysis.
  • Wave Propagation and Nonlinear Chaotic Dynamics.