Rheological–dynamical analogy: modeling of fatigue behavior

Present paper relates to the analysis of fatigue and fatigue failure of thin long steel bars with the application of a new rheological model and rheological–dynamical analogy (RDA). The analogy has been developed on the basis of mathematical–physical analogy between rheological model and dynamical model with viscous damping, and is aimed to be used for the analysis of inelastic deforming of materials and structures. In this presentation, the aim will be to highlight different aspects of fatigue behavior and fill the gap that other methods cannot. This paper provides a numerical example of obtaining S– N curves of thin long steel bars using RDA model and description of the hysteretic energy dissipation of material subjected to cyclic stresses. First the axial fatigue setup and the experimental results are discussed. The latter in order to demonstrate the ability of the RDA modeling technique, the comparison with Griffith’s theory of fracture is presented. RDA method for fatigue crack growth rate is proposed and compared with Paris power law. On the basis of the comparisons, the present RDA method could be considered as valid and suitable for modeling of fatigue behavior.