Measurement of the three-dimensional residual stress distribution around split-sleeve cold-expanded holes


Özdemir A. T. , Edwards L.

JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN, vol.31, no.6, pp.413-421, 1996 (Journal Indexed in SCI)

  • Publication Type: Article / Article
  • Volume: 31 Issue: 6
  • Publication Date: 1996
  • Doi Number: 10.1243/03093247v31641
  • Title of Journal : JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN
  • Page Numbers: pp.413-421

Abstract

Cold expansion of fastener holes is an increasingly common way of improving the fatigue endurance of airframes.

Although a number of methods of cold expansion are possible, the split-sleeve cold-expansion process is the most

widely accepted and is widely used in the repair and manufacture stages of both military and civil aircraft. In the

present work, the residual stress distribution around split-sleeve coldexpanded holes has been measured as a function

of both position through the plate thickness and around the hole through novel use of the Sachs method. It is found

that the residual hoop stresses being generated at the mid-thickness of the plate at orientation 90" from the position of

the split in the expansion sleeve. It is suggested that this variation must be taken into account both in the implementation

of the technology and in any potential model used for the prediction of fatigue life of cold-expanded holes.