Issue 71

K. Kozáková et alii, Fracture and Structural Integrity, 71 (2025) 211-222; DOI: 10.3221/IGF-ESIS.71.15

of samples. Its dependency on the number of cycles to failure is not indicative of the general fatigue performance of the material but rather of the mutual position of the curves.

Figure 6: PE2: Experimental fatigue data of CRB and notched specimens.

notch radius, r [mm]

0.2

0.1

0.01 (crack)

A [MPa]

456.3 -0.245

439.7 -0.247

190.3 -0.191

B [-]

Table 4: PE2: Coefficients of approximations A , B .

Figure 7: Dependency of the critical distance.

The critical distance of PE1 ranges between 0.25 and 0.89 mm. The mean critical distance calculated from CRB specimens and notched specimens with notch radius r = 0.4 mm is 0.29 mm, the mean critical distance calculated from CRB specimens and notched specimens with notch radius r = 0.2 mm is 0.37 mm, and the mean critical distance from CRB specimens and notched specimens with notch radius r = 0.1 mm is 0.52 mm.

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