Fatigue crack propagation in 7050-T7451 plate alloy

A study has been accomplished to characterize the fatigue crack growth rates and mechanisms in thin and thick plate commercial 7050-T7451 aluminum plate in the L–S orientation. Crack growth and crack shielding with branching behavior of long, through thickness cracks is examined and compared to L–T and T–L oriented growth data. Compact tension specimens and the compliance method were used to determine crack growth rates. Constant ΔK data showed significant retardation of growth rate curves for the L–S orientation in the range of 10–13 MPa√m where branching and splitting parallel to the load axis are dominant growth mechanisms.