Energy-based fatigue failure characteristics of materials under random bending loading in elastic-plastic range

This article presents selected aspects connected to the methods of identification of strain energy density that are used to calculate the fatigue strength of materials. The authors focus on selected methods for determination of energy-based (stress-strain) characteristics of the fatigue life of materials (Wa − Nf), including a new approach for the determination of strain energy density parameter Wa. The paper also contains description and evaluation of models for determining the stress amplitudes σa in the elastic-plastic range, for bending. The developed procedure should give new capabilities in fatigue life calculations.