Prediction of Fatigue Crack Growth at Cold-Worked Fastener Holes

A methodology for the quantitative prediction of crack-growth behavior of cracks emanating at cold-worked fastener holes under fatigue cyclic loading has been developed. The proposed prediction technique is based on an 4'effective stress field'1 concept that accounts for the amount of the compressive residual stress existing at the edge of the cold-worked hole. Stress-intensity factor ranges (A/0 and crack-growth rates (da/d/i) are all formulated in terms of the effective stress field. An existing fatigue-crack-growth analysis computer program has been modified to account for these changes. This program was subsequently used to study the fracturemechanics design development test data. Good correlations have been obtained.