Fourier series based reliability analysis of aeroengine turbine blade under linear fuzzy safety state

A Fourier series method is established to compute fuzzy reliability of aeroengine turbine blade. Based on Fourier series of Normal probability density function (pdf), reliability analysis is carried out under linear fuzzy safety states defined by forms I–III. For aeroengine turbine blade root flange subjected to Normal random variables using form I, fuzzy reliability (Pr) evaluated by Fourier series integration is 0.999787. Moreover in blade edge using form II, Fourier series Pr is 0.999684 by balancing between the fluctuation level and the series number. Furthermore for blade connection under Normal distributed stress using form III, Fourier series Pr is 0.918523. Caused by undetermined factors, error ratios of numerical results range from 1.31 × 10−5 to 2.38 × 10−4. As the exactness, convergence and computational capability of Fourier series method are validated, it can be used in fuzzy reliability of aeroengine turbine blade.