Atomistic Mechanisms of Fatigue in Nanocrystalline Metals

Abstract

We investigate the mechanisms of fatigue behavior in nano-crystalline metals at the atomic scale using empirical force laws and molecular level simulations. A combination of molecular statics and molecular dynamics was used to deal with the time scale limitations of molecular dynamics. We show that the main atomistic mechanism of fatigue crack propagation in these materials is the formation of nano-voids ahead of the main crack. The results obtained for crack advance as a function of stress intensity amplitude are consistent with experimental studies and a Paris law exponent of about 2.

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Document Details

Document Type
Technical Report
Publication Date
Dec 31, 2004
Accession Number
ADA438940

Entities

People

  • Diana Farkas

Organizations

  • Virginia Tech

Tags

DTIC Thesaurus Topics

  • Air Force
  • Amplitude
  • Contracts
  • Dynamics
  • Engineering
  • Failure Mode And Effect Analysis
  • Governments
  • Intensity
  • Materials
  • Materials Science
  • Molecular Dynamics
  • Scientific Research
  • Simulations

Fields of Study

  • Physics

Readers

  • Materials Science (Mechanical Engineering).
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