An Experimental Study of the Interaction of Strain Fields between Coldworked Fastener Holes.

Abstract

This report describes the experimental study investigating the interaction of the residual surface strain fields caused by the coldworking of fastener holes in the near vicinity of one another. Testing was confined to 7075-T& aluminum alloy, 1/4 inch (6.4 mm) in thickness. Fastener holes were .261 inch (6.6 mm) in diameter and the center-to-center separation between adjacent fasteners was 1.75 and 2.0 diameters. Single-row in-line and double-row fastener patterns were the focus of this study. Consecutive and non-consecutive sequences of pattern coldwork were chosen to model possible field situations. Experimental results indicate a direct relation exists between the degree of interaction between strain fields and the center-to-center separation between adjacent fastener holes. As noted from the measurement of residual diametral expansions, unsymmetric hole edge motions result in unsymmetric strain distributions. Sleeve failure and the coldwork of adjacent fastener holes can lead to unwanted residual tensile strains at a hole edge boundary. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1981
Accession Number
ADA099695

Entities

People

  • Gary Cloud
  • Mark Tipton

Organizations

  • Michigan State University

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  • Air Platforms

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  • Air Force
  • Cameras
  • Cold Working
  • Data Processing
  • Data Reduction
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  • Materials Laboratories
  • Materials Science
  • Measurement
  • Mechanics
  • Optical Phenomena
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Readers

  • Phased Array Antenna Design.
  • Structural Health Monitoring of Composite Structures.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).