A Fractional Brownian Motion Model of Cracking

Abstract

An attempt is made to find the fractal cutoff of crack profiles on the tension face of concrete beams subjected to uni-axial bending. Previous work by the authors has shown that such cracking can be interpreted as a non-Fickian diffusive phenomenon resulting from a self-affine random fractal process: specifically fractional Brownian motion (fBm). In addition, a spatial description of the cracking geometry can be found from experimental data using both a (Hurst) scaling exponent and a diffusion-type coefficient. Herein the authors find that the fractal description of the crack profiles extends down to less than 0.75 microns. The use of a scanning electron microscope to probe the crack profile (and surface) at smaller scales is discussed and the synthesis of crack surfaces using fBm is described briefly.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2000
Accession Number
ADP010905

Entities

People

  • A. S. Ndumu
  • L. T. Dougan
  • P. S. Addison
  • W. M. C. Mackenzie

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Brownian Motion
  • Civil Engineering
  • Coefficients
  • Concrete
  • Diffusion
  • Diffusion Coefficient
  • Electron Microscopes
  • Equations
  • Fokker Planck Equations
  • Geometry
  • Magnification
  • Microscopes
  • Probability
  • Probability Density Functions
  • Scanning Electron Microscopes
  • Spatial Distribution
  • Standards

Readers

  • Pavement Materials Engineering.
  • Structural Dynamics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.

Technology Areas

  • Microelectronics