An improved viscoplastic constitutive model and its application to creep behavior of turbine blade

This paper improved Chaboche viscoplastic constitutive model in order to simulate the mechanical behavior of engineering components during service. The anisotropic tensor and Kachanov damage evolution equation were added to the constitutive equation to simulate the creep behavior of anisotropic material. Based on that, the Levenberg-Marquardt nonlinear optimization algorithm was used to obtain material parameters and the constitutive model was compiled as the subprogram of finite element software ABAQUS for its simulation application. Then the improved constitutive model was used to simulate and analyse the uniaxial tensile and creep behavior of specimens made of anisotropic material DZ125 at different loads, and the accuracy and feasibility of material parameters and constitutive model were verified by corresponding test results. Finally, the improved constitutive model was used to simulate the creep behavior of a hollow turbine blade, achieving its engineering application. And the calculated results have great significance for structure design and life prediction of turbine blade.