PSI - Issue 80

ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

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

Procedia Structural Integrity 80 (2026) 423–430

© 2025 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 Ferri Aliabadi Abstract The objective of this study is to clarify the effect of cellulose nanofiber (CNF) added location on the interlaminar fracture toughness of carbon fiber reinforced thermoplastic composites (CFRTP). In this study, two types of CFRTP specimens were fabricated using the sheet lamination method: CFRTP with CNF added to the resin and CFRTP with CNF added to the carbon fiber. The interlaminar fracture toughness of these specimens was evaluated through End Notched Flexure (ENF) and Edge Crack Torsion (ECT) tests to compare the influence of CNF added location. The test results revealed that CFRTP with CNF added to the resin exhibited higher interlaminar fracture toughness than CFRTP with CNF added to the carbon fiber. When CNF was added to the carbon fiber, even a small amount of CNF led to an increased probability of cohesive failure due to CNF aggregation, resulting in decreased interfacial adhesion. In contrast, adding CNF to the resin improved the shear strength at the fiber/resin interface, thereby enhancing interlaminar fracture toughness. In conclusion, these findings indicate that adding CNF to the resin rather than to the carbon fiber is an effective approach to improve the interlaminar fracture toughness of CFRTP. © 2023 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 Professor Ferri Aliabadi Keywords: Type your keywords here, separated by semicolons ; 1. Introduction Carbon fiber reinforced plastic (CFRP) is widely used in various applications such as aerospace and automotive industries due to its combination of high strength and lightweight properties [Deutz et al. (2025); Balcer et al. (2025)]. However, CFRP has drawbacks, including high material costs and time-consuming processing. Fracture, Damage and Structural Health Monitoring Effect of CNF Added Location on the Interlaminar Fracture Toughness of CFRTP Seiji Mitsubayashi a *, Kenichi Takemura a and Ryohei Asakawa b a Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama, 221-8686, Japan b Former graduate student at Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama, 221-8686, Japan Abstract The objective of this study is to clarify the effect of cellulose nanofiber (CNF) added location on the interlaminar fracture toughness of carbon fiber reinforced thermoplastic composites (CFRTP). In this study, two types of CFRTP specimens were fabricated using the sheet lamination method: CFRTP with CNF added to the resin and CFRTP with CNF added to the carbon fiber. The interlaminar fracture toughness of these specimens was evaluated through End Notched Flexure (ENF) and Edge Crack Torsion (ECT) tests to compare the influence of CNF added location. The test results revealed that CFRTP with CNF added to the resin exhibited higher interlaminar fracture toughness than CFRTP with CNF added to the carbon fiber. When CNF was added to the carbon fiber, even a small amount of CNF led to an increased probability of cohesive failure due to CNF aggregation, resulting in decreased interfacial adhesion. In contrast, adding CNF to the resin improved the shear strength at the fiber/resin interface, thereby enhancing interlaminar fracture toughness. In conclusion, these findings indicate that adding CNF to the resin rather than to the carbon fiber is an effective approach to improve the interlaminar fracture toughness of CFRTP. © 2023 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 Professor Ferri Aliabadi Keywords: Type your keywords here, separated by semicolons ; 1. Introduction Carbon fiber reinforced plastic (CFRP) is widely used in various applications such as aerospace and automotive industries due to its combination of high strength and lightweight properties [Deutz et al. (2025); Balcer et al. (2025)]. However, CFRP has drawbacks, including high material costs and time-consuming processing. Fracture, Damage and Structural Health Monitoring Effect of CNF Added Location on the Interlaminar Fracture Toughness of CFRTP Seiji Mitsubayashi a *, Kenichi Takemura a and Ryohei Asakawa b a Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama, 221-8686, Japan b Former graduate student at Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama, 221-8686, Japan

* Corresponding author. Tel.: +81-45-451-5661; fax: +81-45-451-7915. E-mail address: mitsubayashi@kanagawa-u.ac.jp * Corresponding author. Tel.: +81-45-451-5661; fax: +81-45-451-7915. E-mail address: mitsubayashi@kanagawa-u.ac.jp

2452-3216 © 2023 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 Professor Ferri Aliabadi 2452-3216 © 2023 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 Professor Ferri Aliabadi

2452-3216 © 2025 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 Ferri Aliabadi 10.1016/j.prostr.2026.02.041