Numerical analysis of bonded repairs for fastener holes with three-dimensional cracks

M. Heller, R. Jones, J. F. Williams

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6 Citations (Scopus)


Recent finite element analysis has shown that stress intensity values for two-dimensional cracked fastener holes can be significantly reduced through the use of bonded sleeves. Experimental work has also shown that adhesively bonded inserts can significantly increase the fatigue life of both cracked and uncracked fastener holes. In this paper we present the results of elastic finite element stress analyses carried out on fastener holes with three-dimensional crack geometries and consider the use of both bonded sleeves and bonded fibre composite patches. It is shown that the stress intensity factors for these geometries are significantly reduced by using the bonded sleeves and bonded patches separately or together. A limiting factor is considered to be the level of the stresses in the sleeve adhesive, leading to the possibility of fracture or yielding in the adhesive. It has been found that first order estimates of reductions in the stress intensity factor can be obtained for the three-dimensional crack geometries by comparison with simpler finite element or handbook solutions. The reductions in stress intensity factors obtained indicate that fatigue crack growth rates will be significantly reduced and hence the repair approaches considered show great promise for increasing the fatigue life of fastener holes with realistic crack geometries.

Original languageEnglish
Pages (from-to)81-90
Number of pages10
JournalEngineering Fracture Mechanics
Issue number1
Publication statusPublished - 1989
Externally publishedYes

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