Experimental investigation and numerical prediction of fatigue crack growth of 2024-T4 aluminum alloy

•Fatigue crack growths under constant/variable amplitude loading were tested.•Apparent R-effect on stabilized crack growth of 2024-T4 aluminum alloy was identified.•Stabilized crack growth predicted by unified model agrees with experimental data well.•Retarded crack growth can be correlated by the modified Wheeler’s model reasonably. Compact specimens were employed to study fatigue crack growth of 2024-T4 aluminum alloy under constant/variable amplitude loading. Apparent R-ratio effect under constant amplitude loading was identified with the nominal stress intensity factor range. Fatigue crack growth rates predicted by a unified model agreed with the experimental data well. Single tensile overload resulted in significant retardation of crack growth which was fully recovered after propagating out of overload-affected zone. Retarded crack growth induced by three-step sequence loading was heavily dependent on two sequence loading parameters. The influence of variable amplitude loading on crack growth was reasonably characterized by Wheeler’s model.