PSI - Issue 42

Goran Vizentin et al. / Procedia Structural Integrity 42 (2022) 793–798 Vizentin/ Structural Integrity Procedia 00 (2019) 000 – 000

797

5

25% UTS 50% UTS 75% UTS

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06

0 6 12 18 24 30 36 42 48 54 60

Expected number of lifecycles

Time of exposure, months

Fig3. Normalized decrease of expected numbers of fatigue life cycles, polyester/glass composite with (0/45/90)s fiber layout configuration.

4. Conclusions Glass/polyester composite material has been exposed to actual sea environment and in real time in order to ascertain the influence of such harsh environment on material fatigue characteristics. The investigation has indicated to the need for incorporating the time-environmental decaying ultimate tensile stress in the existing S-N curves obtaining procedures. An initial mathematical degradation model based on the data collected during a two-year period submersion in the sea has been proposed. The research results confirmed the importance of environmental degradation of mechanical properties of composite materials in the marine environment. Acknowledgements This research was funded by the University of Rijeka, under the project numbers uniri-technic-18- 200 “Failure analysis of materials in marine environment” and uniri-zip-M- COMARE “ Marine Composite Material Recycling and Re-use ” . References Andreazza, I., Infante, V., Garcia, M.B., Amaral, P., 2020. Flexural fatigue behaviour of an asymmetric sandwich composite made of limestone and cork agglomerate. Int. J. Fatigue 130, 105264. https://doi.org/10.1016/j.ijfatigue.2019.105264 Bond, D.A., 2005. Moisture diffusion in a fiber-reinforced composite: Part I - Non-Fickian transport and the effect of fiber spatial distribution. J. Compos. Mater. 39, 2113 – 2142. https://doi.org/10.1177/0021998305052030 Burhan, I., Kim, H., 2018. S-N Curve Models for Composite Materials Characterisation: An Evaluative Review. J. Compos. Sci. 2, 38. https://doi.org/10.3390/jcs2030038 Cysne Barbosa, A.P., P. Fulco, A.P., S.S. Guerra, E., K. Arakaki, F., Tosatto, M., B. Costa, M.C., D. Melo, J.D., 2017. Accelerated aging effects on carbon fiber/epoxy composites. Compos. Part B Eng. 110, 298 – 306. https://doi.org/10.1016/j.compositesb.2016.11.004 Davies, P., 2020. Towards More Representative Accelerated Aging of Marine Composites, in: Advances in Thick Section Composite and Sandwich Structures. Springer International Publishing, Cham, pp. 507 – 527. https://doi.org/10.1007/978-3-030-31065-3_17 Davies, P., Rajapakse, Y.D.S. (Eds.), 2018. Durability of Composites in a Marine Environment 2, Solid Mechanics and Its Applications. Springer International Publishing, Cham. https://doi.org/10.1007/978-3-319-65145-3 Davies, P., Rajapakse, Y.D.S. (Eds.), 2014. Durability of Composites in a Marine Environment, Solid Mechanics and Its Applications. Springer Netherlands, Dordrecht. https://doi.org/10.1007/978-94-007-7417-9 de Souza Rios, A., de Amorim, W.F., de Moura, E.P., de Deus, E.P., de Andrade Feitosa, J.P., 2016. Effects of accelerated aging on mechanical, thermal and morphological behavior of polyurethane/epoxy/fiberglass composites. Polym. Test. 50, 152 – 163. https://doi.org/10.1016/j.polymertesting.2016.01.010 Djeghader, D., Redjel, B., 2017. Fatigue of glass-polyester composite immerged in water. J. Eng. Sci. Technol. 12, 1204 – 1215. Eftekhari, M., Fatemi, A., 2016. Tensile behavior of thermoplastic composites including temperature, moisture, and hygrothermal effects. Polym. Test. 51, 151 – 164. https://doi.org/10.1016/j.polymertesting.2016.03.011