PSI - Issue 42

Dušan Arsić et al. / Procedia Structural Integrity 42 (2022) 189–195

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Dusan Arsic et al./ Structural Integrity Procedia 00 (2019) 000 – 000

Figure 7. Appearance of the fault tree due to the corrosion fatigue.

Figure 8. Appearance of the fault tree when the crack reaches length a > a c (event A in Figure 7)

Propagation of fracture of the welded structure due to fatigue occurs in three phases [6]: - Existence of the undetected flaw during the manufacturing or initiation of the crack in exploitation; - Gradual stable crack growth according to Paris law [6]: ( ) m C K dN da =   (1) where a is the crack length, N is the number of loading cycles, C and m are the material constants and ΔK is the stress intensity gradient; - Unstable crack growth until the critical length (ac) and appearance of fracture.