Experimental Studies of Coldworked Fastener Holes

Abstract

This report summarizes the accomplishments of this research and catalogs its resulting papers and reports. When an oversized mandrel is pulled through a hole, the material near the hole edge is coldworked. After the mandrel is removed, the elastic restoring forces of material away from the hole generate compressive stresses at the edge. Subsequent tensile loading must overcome the compressive edge stresses, so a considerable improvement in the ultimate or fatigue loading capability of a structure can be achieved. The research was performed in four phases: Phase I-Measurement of the residual strains around coldworked holes. Phase II-Measurement of the location of the boundary between the elastic and plastic regions around the hole. Phase III-A study of fatigue crack initiation and growth from coldworked and noncoldworked holes. Phase IV-A study, similar to Phase III, of holes that had existing cracks and were then coldworked.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1978
Accession Number
ADA051985

Entities

People

  • William N. Sharpe Jr.

Organizations

  • Michigan State University

Tags

DTIC Thesaurus Topics

  • Air Force
  • Aircrafts
  • Applied Mechanics
  • Boundaries
  • Cold Working
  • Continuum Mechanics
  • Diameters
  • Fatigue Life
  • Materials
  • Measurement
  • Mechanical Working
  • Mechanics
  • Plastic Deformation
  • Residual Stress
  • Stress Corrosion
  • Stress Intensity Factors
  • Stresses

Readers

  • Business Analytics
  • Nuclear Civil Defense.
  • Structural Health Monitoring of Composite Structures.