7. Conclusion
In the present research, a novel damage constitutive model was proposed, which combined the TTC relations with continuum damage mechanics. The novel model overcame the disadvantages of power-law equation and Sinh equation that lack of explicit stress and temperature dependence of the constants, and satisfactory interpolation and extrapolation abilities were achieved. The conclusions of this work were as follows:
  1. The novel model accurately predicted the minimum creep rate, rupture time, creep deformation and damage evolution process of GH4169.
  2. The stress and temperature dependence of constants in the novel model were all determined, which overcame the disadvantages of the traditional CDM-based model and made the model have enough interpolation and extrapolation abilities.
  3. Nonlinear creep damage accumulation effect of GH4169 was revealed from the aspect of continuum damage mechanism. Constant will decrease with the increase of stress or temperature, which means that the total life will be reduced when high stress or high temperature loading condition was applied first.