Fatigue crack propagation of an AA2198 aeronautic alloy using a stochastic model

Al-Cu-Li alloys for aeronautic applications have been studied mainly with regard to structural stability and the stochastic model has shown potential to predict the crack propagation under cyclic loadings. This work focuses on the development of new crack propagation simulation methods with the capacity to predict statistical variations in the process for life estimates by stochastic model. To validate the stochastic model, experimental fatigue crack propagation data were obtained using an AA2198 alloy. The Forman model, a classic and consolidated model, was also analysed for comparison. Good results were observed using a non-conservative model (Stochastic) in comparison with a conservative model (Forman). Both models have shown proper behaviour to the experimental curve including the stochastic model which showed a good correlation r to experimental data. These models presented the same trend and are applicable to crack propagation prediction. The contour analysis showed that stochastic model was more accurate than Forman in a few situations.