Entropy Production during Fatigue as a Criterion for Failure. A Local Theory of Fracture in Engineering Materials.

Abstract

A mathematical model of fatigue crack nucleation initiation, and propagation is described using irreversible thermodynamics to quantify the damage caused by plastic straining. A mathematical model for local random yielding is used to derive a local theory of fracture and fatigue crack growth. The classical results of linear elastic fracture mechanics are reproduced; necessary and sufficient conditions for crack extension, critical stress and crack length, and sigmoidal shape of the crack growth curve. However, this model is not limited to small-scale yielding, includes treatment of loading history, and can be applied to crack growth retardation and closure as well as combined loading and spectrum loading. Originator-supplied keywords include: Fatigue crack initiation; Fatigue crack nucleation; Fatigue damage; Fatigue testing; Fatigue theories; Material damping measurements; Material damping theories; Fatigue crack growth. (Author).

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Document Details

Document Type
Technical Report
Publication Date
Dec 15, 1984
Accession Number
ADA151289

Entities

People

  • P. W. Whaley

Organizations

  • University of Nebraska-Lincoln College of Engineering

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Composite Materials
  • Energy Transfer
  • Failure Mode And Effect Analysis
  • Fracture (Mechanics)
  • Friction
  • Materials
  • Materials Science
  • Materials Testing
  • Mathematical Models
  • Mechanical Properties
  • Mechanics
  • Micromechanics
  • Military Research
  • Plastic Properties
  • Resonant Frequency
  • Stress Strain Relations
  • Thermodynamics

Readers

  • Materials Science (Mechanical Engineering).
  • Theoretical Analysis.