Issue 36

M. Arsic et alii, Frattura ed Integrità Strutturale, 36 (2016) 27-35; DOI: 10.3221/IGF-ESIS.36.03

Specimen class

Number of specimens

Initial notch

Specimen dimensions

a [mm]

W [mm]

B [mm]

L [mm]

1 2 3 4 5

0.250 0.351 0.591 0.723 1.125

9.90 9.79 9.90 9.90 9.85

9.50 9.60 9.50 9.70 9.80

40 40 40 40 40

6 6 6 6 6

Table 2 : Geometric characteristics of specimens and sizes of initial notch.

a [mm] 0.250 0.351 0.591 0.723 1.125

∆M [N ∙ mm]

∆σ [MPa] 157.48 141.24 124.41 112.86

R -

f [Hz]

σ a [MPa] 81.03 70.62 62.21 56.43 48.73

S z [MPa]

Specimen class

σ m [MPa] 236.23 211.86 186.62 169.30 146.20

1 2 3 4 5

19200 16100 13600 12200

0.5 0.5 0.5 0.5 0.5

230-240 230-240 230-240 230-240 230-240

315 282 249 226 195

9500

97.47

Table 3 : Examination conditions and fatigue strength properties.

Figure 4 : S-N Relationship for specimens with initial crack a = 0.25 mm.

Figure 5 : S-N Relationship for specimens with initial crack a = 0.351 mm.

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