Creep analysis and service life prediction of turbine blade with progressive damage

Abstract

Creep failure is one of the dominate failure mode for high temperature turbine blade during service. Under the tensile stress caused by large centrifugal force of the blade and the thermal stress and thermal softening of the material, the displacement as well as the creep strain and damage increase gradually. The present paper firstly gives the temperature field of the blade under typical service condition with numerical modelling. Then Norton’s creep constitutive relation and Lemaitre-Chaboche damage model are introduced into the finite element model, and three different working conditions are considered here to investigate its effect on creep service life of the turbine blade. Numerical results show that, the proposed numerical approach can predict the evolution of the creep process and the damage. Meanwhile, the introduction of cyclic factor is capable of reflecting the fatigue effect of cyclic load.