PSI - Issue 3

Stavros K. Kourkoulis et al. / Procedia Structural Integrity 3 (2017) 316–325 S. K. Kourkoulis and I. Dakanali / Structural Integrity Procedia 00 (2017) 000–000

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Fig. 4. The system designed for the ten-point bending.

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Fig. 5. (a); (b) LVDT’s positions; (c) Clip gauges’ positions; (d) PSC electrical contacts; (e) Clip gauges.

The load was applied monotonically under displacement-control mode at a rate ensuring quasi-static loading con ditions. The experiment was to be terminated either when one of the principal constituent elements (marble, titanium bars) failed or when load decreased smoothly due to the pull-out phenomenon. In the present experiment the element failed first was the lowest pair of reinforcing bars (closest to the epistyle’s bottom face) that fractured suddenly. 3. Experimental results 3.1. Traditional sensing techniques In Fig.8a the variation of the deflection at the mid-section of the restored epistyle and the opening of the fracture (distance between the two fragments) are plotted versus time. The similarity of the two plots is striking: For both cases an almost perfectly linear portion is followed by a non-linear one, terminated by a plateau (at about t=1150 s) where the deformation increases rapidly. The variation of the as above quantities (deflection and crack opening against the overall load level is plotted in Fig.8b. Again the plots are quite similar: The linear elastic portion is followed by a non-