PSI - Issue 19

Sara Eliasson et al. / Procedia Structural Integrity 19 (2019) 81–89 Sara Eliasson / Structural Integrity Procedia 116 (2019) 000 – 000

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Figure 3: Fatigue test results from set specimen geometry and developed methodology for fatigue testing, with R = 0.1, f = 5 Hz.

3.1. Digital image correlation

Quasi-static tensile testing was performed while stress-strain was measured with Digital Image Correlation (DIC) using test systems Dantec Dynamics and Aramis. The force was increased gradually with a moderate strain rate until failure and the strains were monitored. It can be observed that during the DIC measurements the strain pattern was not changed significantly, and a distinct strain locus wa s missing, hence the final failure is of a “sudden death” nature without any strain hardening behavior, see Figure 4b. This is also obvious from the strain-stress curve in Figure 4a where five different specimens were tested with DIC measurements.

Figure 4: Showing to the left (a) the stress-strain curves for five specimens based on the DIC measurements, and to the right (b) the DIC strain pattern for a specimen right before final failure,