PSI - Issue 53

Martin Matušů et al. / Procedia Structural Integrity 53 (2024) 29 – 36 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Table 3. Averaged value of limiting energy from single level tests and averaged value from self-heating step tests. Name Series 41 no HT Series 42 240°C Series 43 200°C Series 44 300°C

3429.9

7030.5

8708.9

10634.4

Average of limiting energy from single level tests Φ SN Average from SH-test Φ SH

2865.1 119.7%

7188.4 97.8%

4616.7 188.6%

14516.9

Φ SN / Φ SH

73.3%

Fargione's method has no lower amplitude limit. To limit the prediction of fatigue life in the lower amplitude region, we employed the FKM-Guidelines to estimate the fatigue limit using the ultimate tensile strength and roughness measurement, see [15].

b)

a)

Fig. 6. S-N curve results and Kohout-V ě chet regression curve for a) series 41 - NoHT and for b) series 42 - T240. Estimates of the S-N data positions from the SH step test by the Fargione method are included. Both graphs have indicated field of 80% related to SD (Standard Deviation)

b)

a)

Fig. 7. S-N curve results and Kohout-V ě chet regression curve for a) series 43 – T200 and for b) series 44 – T300. Estimates of the S-N data positions from the S-H step test by the Fargione method are included. Both graphs have indicated field of 80% related to SD (Standard Deviation)