Fatigue reliability assessment of turbine discs under multi‐source uncertainties

TLDR

High‑pressure turbine discs in aircraft engines operate under complex loadings with multi‑source uncertainties that influence fatigue life and reliability. The study establishes a probabilistic framework for fatigue reliability analysis of HPT discs, using finite‑element simulations and Latin hypercube sampling to quantify material variability and load variations. This framework models material variability with a Chaboche constitutive model coupled to the Fatemi‑Socie fatigue criterion and integrates the simulations with sampling. Sensitivity analysis shows that dispersions of basic variables must be considered for fatigue reliability, and the strength‑damage interference model correlates more reasonably with field flight numbers than the load‑life interference model.

Abstract

Abstract 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 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.