The effect of cold expansion on fatigue crack growth life of fastener holes has been generally investigated in open hole specimens. Nevertheless, cold expanded specimens are practically used in bolted and riveted connections possessing different fatigue behavior than open hole specimens. This paper has sought to investigate the fatigue crack growth of cold expanded specimens after being subjected to bolt tightening. A series of numerical simulations were conducted to obtain the stress field around the hole. The numerical outcomes then were incorporated in AFGROW code to investigate the growth of fatigue cracks emanating from bore of the hole. In the analysis, single plates of 7075-T6 Aluminum alloy with plain hole, cold expanded hole and bolted cold expanded hole were included. Results reveal that bolted cold expanded plates exhibit much longer crack growth life when comparing with plates containing open cold expanded and plain holes.
Fatigue Crack Growth, Cold Expansion, Bolt Clamping, AFGROW, Finite Element