A creep stress intensity factor approach to creep–fatigue crack growth

• A new approach for creep–fatigue crack growth is presented.
• The creep stress intensity factor distributions along the crack front are obtained.
• Experimental confirms effectiveness of the proposed approach.

A new parameter for characterization of the crack growth resistance for power plant materials and structures under elevated temperature is introduced in the form of creep stress intensity factor. On this base a crack growth rate approach is developed for the case of creep and fatigue interaction. A numerical method is proposed for estimating the governing parameter of the creep crack tip field in the form of an In-integral along the through-the-thickness straight and curved crack fronts. The application of the introduced parameters through experimental study of the creep–fatigue crack growth rate confirms effectiveness of the proposed approach.