Lifetime prediction for turbine discs based on a modified Walker strain model

We created three-dimensional models of turbine disc and blades of a type of aero-engine according to their geometries. Extant studies show that low cycle fatigue is the main failure mechanism of turbine disc. By using a non-linear elastic-plastic finite element method, the static stress and strain state of the critically high stress regions, which can lead to operational failures, are determined. On the basis of stress-strain relation, a modified Walker strain life prediction model is proposed with no required knowledge on the mean stress correction. Then the predicted life data from the modified Walker strain model are compared with the testing results. After the verification, the modified Walker strain life prediction model and Miner’s rule were applied to predict the lifetime of the turbine disc under various operating conditions.