Fatigue reliability assessment of turbine discs under multi-source uncertainties

Hot section components of aircraft engines like high pressure turbine (HPT) discs usually operate under complex loadings coupled with multi-source uncertainties. The effect of these uncertainties on structural response of HPT discs should be accounted for its fatigue life and reliability assessment. In this study, a probabilistic framework for fatigue reliability analysis is established by incorporating FE simulations with Latin hypercube sampling to quantify the influence of material variability and load variations. Particularly, variability in material response is characterized by combining the Chaboche constitutive model with Fatemi-Socie criterion. Results from fatigue reliability and sensitivity analysis of a HPT disc indicated that dispersions of basic variables {rho, omega 1, sigma(f)'} must be taken into account for its fatigue reliability analysis. Moreover, the proposed framework based on the strength-damage interference provides more reasonably correlations with its field number of flights rather than the load-life interference one.