Molecular Dynamics Simulation of Fatigue Damage in Metals

Abstract

Molecular dynamics simulation was conducted to better understand the mechanism of fatigue failure and to identity a parameter(s) that can indicated progressive damage due to cyclic loading. The Embedded Atom Method (EAM) was used for copper atoms subjected to cyclic loadings. Defective crystal structures including vacancies or impurities were considered for the study. The results showed that there was an increase in potential energy and kinetic energy, respectively, in the metal as the number of cycles increased. This means the metal becomes weaker, i.e., an indication of progressive damage. Therefore, the change of potential energy may be used as an indicator for fatigue damage accumulation. Furthermore, the relative distances between vacancies (or impurities) increased globally with fluctuation as the number of loading-unloading cycles increased.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2003
Accession Number
ADA420653

Entities

People

  • William S. Lunt

Organizations

  • Naval Postgraduate School

Tags

DTIC Thesaurus Topics

  • Crystal Structure
  • Cyclic Loads
  • Electron Density
  • Electrons
  • Energy
  • Kinetic Energy
  • Materials
  • Materials Science
  • Mechanical Properties
  • Modulus Of Elasticity
  • Molecular Dynamics
  • Potential Energy
  • Resonant Frequency
  • Stress Strain Relations
  • Stresses
  • Three Dimensional
  • Two Dimensional

Readers

  • Immunology and Pathology
  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.