Viscoplastic analysis method of an aeroengine turbine blade subjected to transient thermo-mechanical loading

Abstract Viscoplastic analysis method of a turbine blade manufactured with directionally solidified (DS) superalloy under transient thermo-mechanical loading was investigated in depth. The second deviatoric stress tensor invariant was modified by a fourth-order tensor to simulate the anisotropic behavior of the DS superalloy. In order to capture the monotonic and cyclic behaviors of the alloy under non-isothermal conditions, temperature interpolation of a set of material parameters and the modification of internal state variables were performed. The model was implemented as a user subroutine (UMAT) in Abaqus for complex structure analysis. With the improved Chaboche constitutive model, the tensile and cyclic responses of the DS material GTD-111 under isothermal and non-isothermal conditions were carefully modeled and predicted with high accuracy. Finally, the model was implemented to simulate the transient thermo-mechanical behavior of a hollow turbine blade with a typical flight profile. The location-dependent thermo-mechanical fatigue response of the blade were determined and analyzed.