PSI - Issue 64

7

Hamid Dahaghin et al. / Procedia Structural Integrity 64 (2024) 1192–1199 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1198

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Fatigue test

Maximum load: 140.6kN R ratio=0.2

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(a) (b) Fig. 12. (a) Fatigue test setup; (b) Fracture surfaces of the plate repaired with deposited WAAM (Ghafoori et al., 2023b)

Fig. 13. Fatigue a-N curves of the specimens (Ghafoori, et al.,2023b)

Fig. 14. Fractography of the fracture surface of the sample repaired with deposited WAAM (a), (b), (c), and (e) macro fracture morphology, (d) and (f) microfracture morphology (Ghafoori et al., 2023b).

Moreover, the fatigue fracture surface of the deposited WAAM repair specimen was characterized at macro- and micro-levels, revealing diverse areas such as crack initiation, propagation, and final fracture. Fig. 14 displays the fracture morphology of the fatigue crack initiation and propagation region in the as-deposited WAAM specimen. It illustrates crack nucleation occurring at the interface between the steel substrate and the WAAM profile. Upon closer examination in Fig. 14, crack initiation zones are observed at the edge of the WAAM profile, particularly near stress concentrators and sharp corners. Various ductile fracture features and dimples of different sizes are evident.