Identification of Viscoplastic Constitutive Parameters of GH3536 Superalloy

To investigate the deformation behavior of GH3536, a material commonly used in aero-engine combustion liner, the mechanical properties were modeled using the Chaboche unified viscoplasticity constitutive. To accurately simulate the tertiary creep deformation, the Robotnov creep damage rate was coupled into the Chaboche model. The constitutive equations were discretized into a set of differential equations using the backward Euler method. Material parameters were then identified and optimized by employing a multi-island genetic algorithm. Finally, the Chaboche model was implemented into ABAQUS software through the user material subroutine UMAT for numerical simulation. Based on the constitutive model, the long-term (creep) and short-term (uniaxial tension, fatigue, creep-fatigue interaction) mechanical behaviors of GH3536 under multiple temperature conditions (20~1000 °C) were characterized uniformly. Numerical results reveal good consistency between simulated and the experimental outcomes. demonstrating that the Chaboche model coupled with Robotnov creep damage rate uniformly described the mechanical behavior of GH3536.