PSI - Issue 64

Valentina Tomei et al. / Procedia Structural Integrity 64 (2024) 901–907 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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with self-monitoring capabilities, particularly helpful in application in the field of Cultural Heritage restoration. H_Fh_dog-bone

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0 normal stress  [MPa]

H_Fd_dog-bone

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(a) (b) Figure 5. (a) normal stress-strain curves for samples with fiber optic embedded; (b) failure modes.

0.03

H_Fh(s)_dog-bone

sample N.1 sample N.2

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strain [-]

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Figure 6. strain-time curves deduced from the samples H_Fd(s)_dog-bone equipped with fiber optic with sensor.

4. Conclusions The paper has presented experimental findings from tests conducted on samples fabricated using 3D printing technology. Specifically, all samples were made of PLA material and produced using various printing processes to insert a fiber optic inside them. Additionally, an artificially induced aging process was applied. The analysis revealed the significant impact of both the printing process and the aging effect, as well as the specific procedure used to introduce the fiber optic into the sample. In particular, concerning the samples with fiber optic, an increase in the average elastic modulus (around 50%) was observed, likely due to the fiber's contribution to stiffness. Additionally, there was a reduction in both ductility and strength (the latter by approximately 12%) compared to the H_dog-bone specimen. Furthermore, post-peak behavior of samples with fiber optic was characterized by gradual strength degradation (softening), possibly due to the multi phase printing process here employed. Comparing the behavior of samples with and without fiber optic but using the same printing process, it emerged that while samples with fiber optic filament exhibited higher average elastic modulus (about 30%) and strength (around 13%), both sets of samples displayed similar post-peak behavior with softening.