Three-Dimensional Aspects of Fatigue Crack Closure.

Abstract

This final report summarizes progress on a basic research effort to determine three-dimensional aspects of the relationship between applied load and fatigue crack face separation. The research was motivated by the well known crack closure phenomenon, which indicates that naturally occurring fatigue cracks are physical held shut (or propped open) at zero load, so that crack surfaces do not separate in a linear elastic manner. Although prediction of fatigue crack opening behavior is of fundamental importance to many aspects of crack growth, relatively little is known about the three-dimensional character of closure. The research employed experimental and numerical procedures to develop predictive techniques for this important aspect of crack closure. Optical interference was used to measure crack opening in transparent polymer specimens, along with conventional crack opening and back face strain techniques for measuring crack closure. A numerical algorithm was developed to predict opening loads in surface flawed plates, and was compared with the experimental results. Keywords: Crack propagation, Cracking(Fracturing).

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1988
Accession Number
ADA192296

Entities

People

  • A. F. Grandt
  • J. E. Pope
  • S. K. Ray

Organizations

  • Purdue University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Cracks
  • Finite Element Analysis
  • Fracture (Mechanics)
  • Gages
  • Geometry
  • Intensity
  • Materials
  • Measurement
  • Mechanics
  • Modulus Of Elasticity
  • Sensitivity
  • Steady State
  • Strain Gages
  • Stress Intensity Factors
  • Tensile Stress
  • Three Dimensional
  • Two Dimensional

Readers

  • Computational Fluid Dynamics (CFD)
  • Materials Science (Mechanical Engineering).