R-ratio Effect And Crack Closure Model In Al-alloy

Fatigue crack closure phenomenon is now recognised as one of the most influential mechanisms operating during fatigue. The crack closure effect helps explain a wide range of fatigue data. It has become the default interpretation of stress ratio effects. It is used in almost all fatigue life prediction models. In this investigation an attempt was made to shown effect of crack closure based on experimental fatigue crack growth data of 2024 T351 Al-alloy using fourth bending fatigue test under differents stress ratio. Elber crack closure model was applied. The results show a good calibration of cracking curves for low stress intensity factor. Although there have been bad timing curves cracking for high stress intensity factor. For this reason, coefficients of Elber model must be adjusted to have an intrinsic curve using Aliaga et al. method. The present fatigue crack growth curves are also compared to curves using several crack closure models (Katcher/Kaplan model, Schijve model, and benguediab model).