PSI - Issue 33

V.P. Matveenko et al. / Procedia Structural Integrity 33 (2021) 925–932 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 2. Experimental setup.

In total six loading steps were applied during the experiment, which are shown in the Fig. 3. During the experiment, at each stage of loading, strains were measured using the embedded DFOS.

Fig. 3. Experimental loading steps.

It is worth noting that the authors of the work carried out similar tests to register the mechanical behavior and state of a cement sample, but using embedded FBG sensors. The sample studied in (Kosheleva, Serovaev and Gusev, 2021) was created simultaneously and under the same conditions as in this work, and was tested under the same loads. For verification and comparison of measurements obtained by DFOS, Fig. 4a shows the values of measured strains by DFOS and FBG sensors, as well as the results obtained using numerical simulation by the finite element method. The described experiment was carried out at ambient room temperature with insignificant temperature fluctuations over time. Due to this, a hypothesis about isothermal conditions of the experiment is assumed, which allows to neglect the temperature term when calculating strain on the basis of the physical quantity recorded by the distributed FOS. The results are given for one of the sections of the optical fiber located in the zone