Numerical Simulation of Creep Damage and Life Prediction of Superalloy Turbine Blade

Abstract

Creep caused failure is an important failure mode of the turbine blade. A numerical approach of life assessment of the superalloy turbine blade is proposed in the present paper based on the Lemaitre-Chaboche creep damage model. Material damage is introduced into each element based on the ANSYS APDL function, and the creep damage effect is considered through the modification of Young’s modulus. At last, the strength life and stiffness life of the blade can be obtained through the maximum damage and maximum creep strain criterion, respectively. The present method can not only consider the effect of creep damage, but also give the time histories of the element stresses, damage, and creep strain. The above life prediction results based on the proposed method are compared with theθprojection method, and the results suggest that the present life prediction method of turbine blade is feasible and turbine blade’s life in the present study is determined by creep fracture rather than creep deformation.