PSI - Issue 61

Zili Huang et al. / Procedia Structural Integrity 61 (2024) 252–259 Huang et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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tests. While drop of load bearing capacity due to cracking can be observed in all three tests (Figs. 3b, 3d and 3f), strong snap-back can be seen in the last two cases (Figs. 3d and 3f). In these two cases of strong snap-back, the lateral displacements are still increasing steadily, as seen in Figs. 3a, 3c and 3e. This indicates the success of AUSBIT in stabilizing fracturing processes. The duration of all three tests shown in Fig. 3 exceeds 4 hours, allowing the use of advanced instrumentation based on DIC. Therefore, full-field strain measurement can be possible for the whole duration of the tests. Fig. 4 shows contours of lateral strain at five stages of test 2 (Figs. 3c and 3d). The cracking process is well under control, and crack observed on the surface of the specimen seems to grow steadily despite snap-back response. The failure pattern is also indicated, showing non-straight crack path due to the heterogeneity of the specimen. In this case the crack cuts through all six layers and the peak load in this case can be associated with tensile strength of the layer.

Fig. 4. evolution of lateral strain, and failure pattern observed at the end of the test (90° loading angle).

3.2. Discontinuity aligned to the applied load (0° loading angle) Fig. 5 shows the results obtained on specimens tested with loading direction aligned with the interface.

Fig. 5. (a, c) evolution of load, vertical displacement and lateral displacement with time; (b, d) load-displacement curves, for two tests (0° loading angle).