Effect of Particle Shape on the Mechanical Behavior of Granular Materials. A Discrete Element Study.

Abstract

An existing two dimensional Discrete Element numerical model which incorporates elliptical particles is used to simulate the biaxial shear of particulate systems. Comparisons are made with physical tests on circular and oval shaped rod systems. Good quantitative agreement was found with the circular rod data, but significantly weaker and softer response was found compared with the oval rod data. This discrepancy is attributed to differences in particle shape in the physical and numerical tests. Additional simulations were conducted using bedded, strongly anisotropic systems at varying degrees of particle flatness. These exhibit distinctly different stress strain and strength behavior, as well as different controlling mechanisms, as function of particle flatness and bedding plane orientation. Shear bands were observed in some flatness and bedding combinations. Interparticle interlocking, dilatancy and inhibition of particle rolling were all observed. Samples with bedding normal to the principal stress direction exhibited the highest shear resistance, as well as largest dilatancy. In systems composed of flat particles with bedding parallel to one of the planes of maximum obliquity, shear bands sometimes formed in the maximum obliquity plane opposite to the bedding plane.

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Document Details

Document Type
Technical Report
Publication Date
Nov 30, 1995
Accession Number
ADA303863

Entities

People

  • Jeffrey D. Rowell
  • John M. Ting
  • Larry R. Meachum
  • Mahmood Khwaja
  • Wai-lim Chin

Organizations

  • University of Massachusetts Lowell

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Civil Engineering
  • Computer Programs
  • Computers
  • Failure Mode And Effect Analysis
  • Geometry
  • Geotechnical Engineering
  • Granular Materials
  • Graphical User Interface
  • Materials
  • Mechanics
  • Modulus Of Elasticity
  • Operating Systems
  • Shear Bands
  • Shear Modulus
  • Simulations
  • Two Dimensional

Readers

  • Aerosol Science/Aerosol Physics
  • Geotechnical Engineering.
  • Mechanical Engineering/Mechanics of Materials.