Fretting fatigue life of materials can be improved by surface treatment such as shot peening. In this investigation, the effect of multiple re-shot peening on the fretting fatigue behavior of Al7075-T6 is studied. After each re-shot peening, the specimen was subjected to 60% of its expected fretting fatigue life. The process of re-shot peening continued until the effect of any further re-shot peening became insignificant. The results showed an increase of 60–70% for the first re-shot peening depending on stress level. The increase, however, was sharply reduced for the next re-shot peenings such that for the third re-shot peening the increase dropped below 10%, which was not as significant. On the whole, the fretting fatigue life increased by 390–410% with respect to the life of virgin specimens depending on the stress level. The results indicated that fretting fatigue life improvement using the 60% of prior life consumption was considerably lower than that obtained for the 80% of expected life as used in previous investigations. An artificial neural network can be employed for estimation of fretting fatigue life at the stress levels not considered in the investigation.
