Low cycle fatigue life prediction of 316 L(N) stainless steel based on cyclic elasto-plastic response

Low cycle fatigue (LCF) tests were carried out on 316 L(N) stainless steel at room temperature employing strain amplitudes ranging from ±0.3% to ±1.0% and a strain rate of 3 × 10−3 s−1. The material showed initial hardening for a few cycles followed by prolonged softening, saturation and final failure. The fatigue life was found to decrease with increase in strain amplitude. The analysis of the stable hysteresis loops under the tested conditions showed Masing behavior at lower strain amplitudes but non-Masing behavior at higher strain amplitudes. The elasto-plastic response of the material under cyclic loading was characterized taking into account isotropic and kinematic hardening occurring during cyclic loading. The material parameters required for characterization of cyclic behavior were obtained from the experimental hysteresis loops and cyclic stress response of the material. Finite element (FE) analysis of elasto-plastic deformation was carried out to obtain the hysteresis loop and cyclic stress response of the material. The predicted hysteresis loops from simulation showed good agreement with experimental results. The low cycle fatigue life prediction carried out based on plastic strain energy dissipation with cycling showed good correlation with experimental results.