As to the sonic fatigue problem of an aero-engine combustor liner structure under the random acoustic loadings

an effective method for predicting the fatigue life of a structure under random loadings was studied. Firstly

the probability distribution of Von Mises stress of thin-walled structure under random loadings was studied

analysis suggested that probability density function of Von Mises stress process accord approximately with two-parameter Weibull distribution. The formula for calculating Weibull parameters were given. Based on the Miner linear theory

the method for predicting the random sonic fatigue life based on the stress probability density was developed

and the model for fatigue life prediction was constructed. As an example

an aero-engine combustor liner structure was considered. The power spectrum density (PSD) of the vibrational stress response was calculated by using the coupled FEM/BEM (finite element method/boundary element method) model

the fatigue life was estimated by using the constructed model. And considering the influence of the wide frequency band

the calculated results were modified. Comparetive analysis shows that the estimated results of sonic fatigue of the combustor liner structure by using Weibull distribution of Von Mises stress are more conservative than using Dirlik distribution to some extend. The results show that the methods presented in this paper are practical for the random fatigue life analysis of the aeronautical thin-walled structures.