Influence of gust spectrum variations on fatigue crack growth behaviour of damage tolerant aluminium-lithium sheet materials

Flight simulation fatigue growth tests were done on 1.6 mm thick sheets of the damage tolerant aluminium-lithium (Al-Li) alloys 2091-T84 and 8090-T81 in comparison with the industry standard conventional damage tolerant alloy 2024-T3. The flight simulation load spectrum, the gust spectrum MINITWIST, was used in four versions: untruncated,...

Manoeuvre spectrum fatigue crack propagation in aluminium alloy sheet materials

2024-T3, 2048-T851, 7075-T6 and 7475-T761 aluminium alloy sheets were compared for fatigue crack propagation resistance under manoeuvre spectrum and constant amplitude loading. For manoeuvre spectrum loading 7475-T761 was superior overall, and this superiority is most probably due to superior toughness of this alloy. In more detail, 2024-T3 was...

Effects of crack plane orientation transitions on flight simulation fatigue crack propagation in a high strength aluminium alloy (7050)

The effects of flat to slant fracture transitions on flight simulation fatigue crack propagation in specimens of 7O5O aluminium alloy forgings are discussed. For specimens containing flat, shearlipped, or full slant fractures at similar crack lengths the crack resistance (R curve) approach appears to provide an explanation for differences in the...