Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in (alpha)RDX

Abstract

This work reports on the algorithms used to determine the anisotropic and isotropic elastic properties of dislocations and their nucleation from a crack tip. The appendix contains a numerical implementation of these algorithms in Matlab. The algorithms are demonstrated for the the energetic molecular crystal RDX, which has orthotropic elastic constants. The energy prefactor tensor is determined for several dislocation and crack tip configurations for RDX in order to calculate dislocation nucleation thresholds for different loading scenarios. Anisotropic results are compared to results obtained using isotropic material averages. The case of crack tip shielding due to partial dislocation nucleation is also presented. The anisotropic elastic results for the KII load factor required for dislocation nucleation are shown to compare well with recently published molecular dynamics simulations of this process.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2013
Accession Number
ADA592063

Entities

People

  • Jaroslaw Knap
  • Lynn B. Munday

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Algorithms
  • Crack Tips
  • Cracks
  • Department Of Defense
  • Dynamics
  • Elastic Properties
  • Engineering
  • Equations
  • Materials
  • Mechanics
  • Military Research
  • Modulus Of Elasticity
  • Molecular Dynamics
  • Shear Modulus
  • Simulations
  • Stiffness
  • Stress Intensity Factors

Fields of Study

  • Materials science

Readers

  • Computational Modeling and Simulation
  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.