Denis Benasciutti

Low cycle fatigue (LCF) regime was experimentally studied for a 316L steel additively manufactured by laser‐powder bed fusion (L‐PBF), a material widely used in sectors that require a reliable durability analysis. Material cyclic elastoplastic behavior is described by the Chaboche–Voce combined plasticity model, which displayed a great degree of accuracy. The fatigue life was modeled by both invoking the Manson–Coffin curve and other simplified models derived from static properties of the material; some of which showed remarkably good accuracy. A quantitative comparison with a wrought‐processed 316L steel displayed a markedly different cyclic elastoplastic response but comparable fatigue strengths.

The uncertainty of rainflow fatigue damage is evaluated for stationary loadings and for non-stationary switching loadings with a finite number of stationary states. The approach is based on confidence intervals constructed after direct analysis of stress-time histories. The accuracy of confidence intervals is verified first by numerical simulations, and then by experimental data measured in a mountain bike traveling under various driving and road surface conditions, yielding stationary and non-stationary switching loadings. Stationarity and non-stationarity of loading records is checked by a statistical method (run test). In experiments, a small set of records (validation set) is also collected and used to approximate the expected damage, which serves for verification purposes. Not only do numerical and experimental results confirm the correctness of the proposed confidence interval for damage, but they also emphasize its usefulness in real engineering applications.