PSI - Issue 37

V.P. Matveenko et al. / Procedia Structural Integrity 37 (2022) 508–516 Matveenko V.P., Kosheleva N.A., Serovaev G.S./ Structural Integrity Procedia 00 (2021) 000 – 000

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Fig. 12. (a) Cement sample compressive loading scheme; (b) Reflected spectra during loading for cement sample.

At last 3D printed samples were tested under compressive loading according to a scheme similar to the cement sample (Fig.13a). However, reliable results were not achieved due to poor adhesion between the optical fiber and the host material. As a result, the fiber-optic sensor turned out to be weakly sensitive to the applied load, which is reflected in Fig. 13b, where it is seen that the FBG spectrum almost didn’t experience any noticeable shift under the loading. a b

Fig. 13. (a) 3D printed sample compressive loading scheme; (b) Reflected spectra during loading for 3D printed sample.

4. Conclusions The paper presents the results of embedding fiber-optic sensors based on Bragg gratings into such structural materials as epoxy resin, cement, 3D printing plastic and poured liquid plastic. FOSs written in an optical fiber with a standard polyimide coating without additional protection was used. Optical spectra reflected by Bragg gratings during material formation are given. The possibility of obtaining information about the evolution of process-induced strains during the material formation process has been demonstrated. It is shown that some materials, for example, poured liquid plastics, due to a fast chemical reaction and a rapidly increasing temperature, can significantly distort