Prediction of short fatigue crack propagation behaviour by characterization of both plasticity and roughness induced crack closures

A new fatigue crack growth model was proposed to characterize short fatigue crack growth behaviour, through combining the mechanisms of both plasticity induced crack closure and fracture surface roughness induced crack closure. The results obtained using this proposed model show good agreement with the analytical predictions of Budiansky–Hutchinsonʹs complex function-analytical solution, and are reasonably close to the experimental data acquired by other researchers. In addition, the results of short fatigue crack growth rate versus stress intensity factor range predicted by the present model can well characterize the experimental results for a 2024-T3 structural aluminium alloy under two different constant-amplitude cyclic loads, and the predictions from the present model also show the reasonable improvement compared to Newmanʹs plasticity induced closure model.