Test procedure to determine the Paris equation coefficients for crack growth rates exemplified by aluminum alloy 2024-T3

Abstract The coefficients of the Paris equation for crack growth rates represent fundamental material properties describing the resistance against crack propagation. Up to now, there is no unified procedure to identify these parameters. The current paper shows an approach for testing and analytical processing of its results which makes it possible to obtain the intermediate region of fatigue crack growth rates on a da/dN-ΔK curve as a result of each test. Also, ways to estimate the crack closure effect on fatigue crack growth and computation of effective ranges of stress intensity factor are shown. The approach was validated by the example of an aluminum alloy 2024-T3. Further development trends for the described method are proposed.