PSI - Issue 66

Davide D’Andrea et al. / Procedia Structural Integrity 66 (2024) 449–458 D’Andrea et al./ Structural Integrity Procedia 00 (2025) 000–000

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Fig. 6. a) Temperature evolution during a stepwise fatigue tests; b) Determination of the fatigue limit according to RTM.

4.4. Comparison of fatigue data In Fig. 7 are reported the estimation of the limit stress from the STM applied on the specimens of the current work (white specimen) and the constant amplitude (CA) fatigue test results, performed in another work [19] on the same material obtained by MJF, and its limit stress estimation (black specimen). As it is possible to note, the limit stress prediction is in good agreement; indeed, the limit stress of the present work specimens falls within the scatter band of [19]. In addition, the CA fatigue tests show failures and run-outs between the limit stress prediction. Finally, the fatigue limit assessed by RTM is in good agreement with the finding of the STM. It is to point out that applying the STM and the RTM a reasonable saving of time and material for the assessment of the first damage within the material and its fatigue limit compared to traditional CA fatigue tests.

Fig. 7. Comparison between the limit stress and the CA fatigue tests from Santonocito 2020.