PSI - Issue 42

Kamila Kozáková et al. / Procedia Structural Integrity 42 (2022) 270–275 K. Koza´kova´ et al. / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 6: Wo¨hler curves for notched and smooth specimens tested under frequency of 20 kHz

of 0.8 mm shows shorter fatigue life than the specimens with a notch radius of 0.4 mm. Due to these unexpected results we decided to analyse the surfaces of notches, see Fig. 7. Photomicrographs were taken after the fatigue tests.

(a) r = 0 . 1 mm, SEM

(b) r = 0 . 2 mm, SEM

(c) r = 0 . 4 mm, SEM

(d) r = 0 . 8 mm, SEM

(e) r = 1 . 5 mm, SEM

(f) r = 3 . 0 mm, SEM

Fig. 7: Surfaces of notches with radii r