PSI - Issue 57

9

Mathilde Renault et al. / Procedia Structural Integrity 57 (2024) 22–31 Mathilde RENAULT / Structural Integrity Procedia 00 (2019) 000 – 000

30

The fatigue results are then compared with those obtained by (Bercelli et al. 2022) as illustrated in Figure9

Figure9: Comparison between transversal and longitudinal orientation (longitudinal results are from (Bercelli et al,2020)

Fatigue behavior differed between the 2 directions studied; the specimens taken in the transverse direction show better fatigue strenght for the 4-point bending stress. Also, the IR data show that crack detection in the transverse configuration occurs later than in the longitudinal configuration. However, the crack propagation kinetics are similar. In the light of these results, it seems that the initiation phase is affected by the direction of stress. 6. Conclusion In this study, we focused on the surface roughness and cracking behavior of Wire Arc Additive Manufactured (WAAM) parts. Through 4-point bending fatigue tests monitored by an infrared camera via TSA, we conducted a thorough assessment of the surface roughness and its effects on crack initiation and propagation. The transverse configuration exhibited delayed crack initiation compared to the longitudinal configuration, and the transverse specimens demonstrated significantly higher lifetimes. Acknowledgements This study belongs to the “Self - Heating” ANR -Safran-Naval Group research chair (grant no. ANR-20-CHIN 0002), involving Safran Companies, Naval Group, ENSTA Bretagne (IRDL), and Institut Pprime.