Improvements to predicting fatigue crack growth rates in aluminium alloy (AA7050-T7451) loaded with a standard transport aircraft spectrum

The accurate prediction of fatigue crack growth is vital to design, structural airworthiness and safety; hence of great interest to fleet manufacturers, operators and maintainers. The Defence Science and Technology Organisation (DSTO) has been developing a novel testing method to obtain data to improve fatigue life prediction capabilities. This paper presents research undertaken at DSTO and Royal Melbourne Institute of Technology, into a new material model for predicting crack growth rates for a typical flight spectrum. A small coupon fatigue test study was undertaken, and post-test crack growth measurements were found to compare favourably with the proposed updated model's results.