PSI - Issue 30

ScienceDirect Available online at www.sciencedirect.com Sci nceD rect Structural Integrity Procedia 00 (2020) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000–000 Available online at www.sciencedirect.com

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 30 (2020) 162–166

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors Abstract Atmospheric moisture is one of the main climatic factors for polymer composite materials and has the greatest impact on the surface layers of materials. In a cold climate and in seasonal and daily climatic thermal cycling at a transition below 0 °C, the accumulated water in the pores and capillaries of polymeric materials accelerates the appearance of microcracks, their coalescence and the formation of macrodamages in the bulk of the binder and at the boundary with the fibers. The paper presents the results of experiments to study the effect of low temperature on the properties of water-saturated fiberglass with a macrocrack by the method of acoustic emission. Comparative analysis of dried and water-saturated glass fiber laminate samples, containing 0.98% water, showed that for water-saturated samples, acoustic radiation is observed with a pulse amplitude that is more than two orders of magnitude higher than the background. This makes it possible to associate acoustic emission pulses with ice crystallization processes, an increase in internal stresses during the transition of water into ice at the crack tip, and multiple acts of microdamage to the binder generating acoustic pulses. The indicators of the emerging microdamages in the polymer matrix and at the interface between it and the filler are the mean square value of acoustic emission voltage. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors Keywords: polymer composite materials, thermal cycles, internal stresses, micro-cracks, water, freezing, acoustic emission. Abstract Atmospheric moisture is one of the main climatic factors for polymer composite materials and has the greatest impact on the surface layers of mat r als. In a cold climate and in seasonal and daily li atic thermal cycli g at a transition below 0 °C, accumul ted water in the pores and capill ries of polymeric materials c elerates the appear nce of microcracks, their coalescence and he formation of m crodamages in the bu k of the binder and at th boundary with the fibers. The paper presents the r ults of experiments o study the effect of low emperature on the p operties of water-saturated fibergla s with macrocrack by the method of acoustic emission. Comparative analysis of dried and water-saturated glass fib r laminate amples, containing 0.98% wa er, showed that for water-saturated samples, acoustic radiation is observed with a pulse pli ude that is more than two orders of magnitude higher han he background. This makes it pos ible to associate acoustic emission pul es with ice crystallizati n processes, an increase in internal stresses during th transition of water into ice at the rack tip, and multiple acts of microdamage to th binder g nerating acoustic pulses. The indicators f the em rgi g microdamages in the polymer matrix and at the interface between it and the filler are the mean square value f acoustic iss on voltage. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der responsibility of EURASTRE COLD - 2020 guest editors Keywords: polymer composite materials, thermal cycles, internal stresses, micro-cracks, water, freezing, acoustic emission. IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Effects of moisture on aging of polymer composite materials in a cold climate IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Effects of moisture on aging of polymer composite materials in a cold climate O.V.Startsev a , A.K. Kychkin b *, M.P Lebedev a , V.V. Polyakov c a Federal Research Centre “The Yakut Scientific Centre SB RAS”, 2 Petrovskogo St.,Yakutsk 677000, Russia b Larionov Institute of Physical-Technical Problems of the North SB RAS, 1 Oktyabrskaya St., Yakutsk 677980, Russia c Altai State University, 61 Pr. Lenina, Barnaul, 656049, Russia O.V.Startsev a , A.K. Kychkin b *, M.P Lebedev a , V.V. Polyakov c a Federal Research Centre “The Yakut Scientific Centre SB RAS”, 2 Petrovskogo St.,Yakutsk 677000, Russia b Larionov Institute of Physical-Technical Problems of the North SB RAS, 1 Oktyabrskaya St., Yakutsk 677980, Russia c Altai State University, 61 Pr. Lenina, Barnaul, 656049, Russia

* Corresponding author. Tel.: +7-914-225-35-97 E-mail address: kychkinplasma@mail.ru * Corresponding author. Tel.: +7-914-225-35-97 E-mail address: kychkinplasma@mail.ru

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open-access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of the EURASTRENCOLD - 2020 guest editors 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open-access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of the EURASTRENCOLD - 2020 guest editors

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors 10.1016/j.prostr.2020.12.025