Probabilistic fatigue assessment of notched components under size effect using generalized weakest-link model

• A generalized weakest-link model for probabilistic fatigue assessment of notch components. • Framework for calculating the probability of fatigue failure under notch and size effects. • Experimental data of GH4169 and TC4 alloys verified the model predictions accuracy. • Fatigue assessment of a turbine bladed disk under different rotating speeds was conducted. Fatigue assessment in the presence of intricate geometries is critical for ensuring reliability and structural integrity of engineering components. This study proposes a generalized weakest-link model for probabilistic life prediction of notched components considering statistical and geometrical size effects, in which the failure probability of materials at different positions is quantified by a weight function of stress field intensity (SFI) approach. In particular, with a new definition of fatigue failure region (FFR), the size effect on notch fatigue behavior is reasonably characterized. Model validation and comparison are performed with experimental data of GH4169 and TC4 notched specimens. Note that the scattering fatigue data points agree well with the model predicted P – S – N curves. Finally, the proposed generalized weakest-link model is applied to fatigue strength assessment of a turbine bladed disk.