Multiaxial fatigue life prediction for turbine blades using finite element analysis

The High-Pressure (HP) turbine blade of aero-engine is subjected to high temperature and high pressure, whose life is mainly governed by the fatigue. In order to model the working condition and obtain the critical area, the Finite Element Analysis (FEA) software ANSYS is typically used as a mathematical tool to solve the problems. Besides, the Chaboche model is employed as a constitutive model to describe the response behaviors of the materials under cyclic loadings in the software. The Fatemi-Socie (FS), Wang-Brown (WB) and Redefined Smith-Watson-Topper (Re-SWT) models are utilized to estimate the life of turbine blades on the basis of the critical plane criteria, which considers the effects of hardening due to non-proportional cyclic loading and mean stress on the multiaxial fatigue life of material. Furthermore, these models are applied to proportional and non-proportional loadings. The analysis results indicate that the critical region of HP turbine blade which should be enhanced the intensity or redesigned to reduce the stress concentration.