A Plastic Strain and Stress Analysis of Bending and Torsion Fatigue Specimens in the Low-cycle Fatigue Region Using the Finite Element Methods

The assessment of a reliable S-N curve requires an accurate determination of stresses involved. If the stress state is complicated like in a plastic field of deformation the stress for a neck specimen may not always be calculated using formulae available in standard handbooks. Furthermore, the stress may vary from one point to another in a manner which is difficult to predict. This situation arises for instance during bending, torsion and also combined of fatigue specimens loading. In this article a numerical analysis of stresses generated in bending and torsion fatigue specimens has been performed employing the commercially available FEM program ADINA. Computer simulation has been performed on fatigue specimens from high-strength steel DOMEX 700 MC D.