Issue 78

S. Vantadori et alii, Fracture and Structural Integrity, 78 (2026) 432-453; DOI: 10.3221/IGF-ESIS.78.25

th K  [MPam 0.5 ]

R

3.00 3.22 2.84 2.93 2.15 2.32

0.10

0.50

0.75

th K  , determined at different fatigue ratio, R , values.

Table 5: Threshold stress intensity factor range,

(a)

(b)

(c)

(d)

0.10 R  : (a) Sub-Stage IIa, (b) Sub-Stage IIb, and (c) and (d) Sub-Stage IIc.

Figure 12: Fatigue fracture surface morphologies for

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