The effect of gust alleviation on fatigue in 2024-T3 Alclad

Fatigue tests under flight simulation loading were done on simple notched 2024-T3 Alclad sheet specimens. Reduction of the gust load amplitudes resulted in an increase of crack initiation life but hardly influenced crack propagation. Reduction of the overall stress level increased both initiation and crack propagation life. The observed...

Flight simulation fatigue crack propagation evaluation of candidate lower wing skin materials with particular consideration of spectrum truncation

Flight simulation fatigu-e crack propagation tests were carried out on 2024-T3, 7475-T761 and mill annealed Ti-6A1-4V sheet in thicknesses up to 3 miri and representative for transport aircraft lower wing skin stiffened panels of end load capacities 1.5 and 3 MN/m. The performance of 2024-T3 was much superior, owing mainly to greater retardation...

Heat treatment studies of aluminium alloy forgings of the AZ 74.61 type. Interim report no. 3: Fatigue crack propagation performance under manoeuvre spectrum loading

The fatigue crack propagation performance of the alloy AZ 74.61 under manoeuvre spectrum loading was studied. The crack propagation behaviour was also compared with that of the American forging alloy AA 7050, not only for simulated manoeuvre loading but also for simulated gust loading and programme loading. It was found that, at comparable...