PSI - Issue 38

Sara Eliasson et al. / Procedia Structural Integrity 38 (2022) 631–639 Author name / Structural Integrity Procedia 00 (2021) 000 – 000

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before processing the images. However, for these uniform and unidirectional specimens the speckle pattern adhered well over the course of the fatigue test. Not all test data had sufficient quality, therefore, not all tested specimens have DIC data.

Fig. 5. An HSC image with coordinate system, and a result image of the strain in y-direction from the DIC analysis in Ncorr.

4. Results 4.1. S-N Data

Fatigue testing was successfully conducted for 18 test specimens (Table 2). There was a high spread in the results, and the results were summarized in an S-N plot which is presented in Fig. 6. The results showed a high spread for both load levels 90 % and 80 % of UTS. Specimens below 80 % of UTS were runouts.

Table 2. Tabular results for fatigue test specimens, with failure codes according to ASTM D3039/D3039M-17 (ASTM International, 2017).

Specimen

Load [% of UTS]

Cycles

Failure Mode

Specimen AT0_10 AT0_11 AT0_12 AT0_13 AT0_14 AT0_15 AT0_16 AT0_17 AT0_18

Load [% of UTS]

Cycles 78 370

Failure Mode

AT0_1 AT0_2 AT0_3 AT0_4 AT0_5 AT0_6 AT0_7 AT0_8 AT0_9

70 78 80 80 80 80 80 80 80

> 2 000 000 > 2 000 000

Runout Runout

80 85 85 85 85 90 90 90 96

LGM GAT LAV LAT

390 370

785 750 500 370 412 530

GIT

SGM

397 040

LIT

1 620

LIT

> 5 000 000

Runout

850

GAT LAV

1 386 450

LIB

2 113 880

> 3 330 000

Runout

150 170

LIT

7 880

LIB

LAT