A generalized energy-based fatigue–creep damage parameter for life prediction of turbine disk alloys

In this paper, a new model for life prediction of turbine disk alloys (GH4133) is proposed. Based on plastic strain energy density, a generalized energy-based fatigue–creep damage parameter is developed to account for creep and mean strain/stress effects in the low cycle fatigue regime. Moreover, the mechanism of cyclic hardening is taken into account within this model. It provides a better prediction of GH4133’s fatigue behavior when compared to the Smith–Watson–Topper and plastic strain energy density methods. Under mean strain conditions, the proposed model provides a more accurate life prediction of GH4133 than that under zero-mean strain conditions.

► Fatigue life evaluation using strain energy parameter was performed.
► A generalized energy-based fatigue–creep damage parameter was established.
► The creep and mean strain/stress effects in life predictions were elaborated based on the energy principle.
► The proposed damage parameter provides a good correlation on GH4133’s fatigue behavior over the temperature range.