For SPEY MK202 engine

the stress standard evaluation methods fail to contain various random factors. In order to explain the differences in the actual working life of engine component

as well as the dispersion of the fatigue characteristic parameters of component and the randomness of the whole engine load spectrum

statistical analysis of measured data

finite element analysis of stress and Monte Carlo simulations of component were combined to put forward the improved algorithm of flight conversion ratio for aero-engine based on probability. Actual example shows: the flight conversion ratio of ascertainable method for life assessment is the average value of the improved algorithm; for a single flight conversion rate

the average conversion rate of improved algorithm is 2% smaller than that of ascertainable method; for comprehensive flight conversion rate

the average conversion rate of improved algorithm is 1% smaller than that of ascertainable method; and the single fight conversion rate and comprehensive flight conversion ratio of improved algorithin are in normal distribution.