PSI - Issue 52

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 52 (2024) 176–186

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

© 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 Abstract In this study, we propose a comprehensive method to evaluate the bond strength of ultrasonic-welded carbon-fiber-reinforced thermosetting-plastic (CFRTP) considering combined stress state. Ultrasonic welding is one of the promising welding methods for CFRTP that are expected to apply to bonding large parts such as aircraft components, but this welding has not been generally applied because the quantitative evaluation method for bonding strength has not been established yet. In the present study, two types of fracture tests are proposed for ultrasonic-welded CFRTP with the goal of evaluating the strength of the adhesive interface considering the combined shear and tensile stresses. One is a ‘compression shear test’, which evaluates the strength when compressive stress is applied in the shear direction to the adhesive interface. The other is a ‘flatwise test’, which evaluates the strength when tensile stress is applied perpendicular to the interface. Finite element analysis (FEM) is used to simulate both tests to obtain accurate shear and tensile stresses, taking into account the combined stress state and stress distribution. Based on the above results, a quantitative and comprehensive evaluation of adhesive strength at the welding interface is attempt. Abstract In this study, we propose a comprehensive method to evaluate the bond strength of ultrasonic-welded carbon-fiber-reinforced thermosetting-plastic (CFRTP) considering combined stress state. Ultrasonic welding is one of the promising welding methods for CFRTP that are expected to apply to bonding large parts such as aircraft components, but this welding has not been generally applied because the quantitative evaluation method for bonding strength has not been established yet. In the present study, two types of fracture tests are proposed for ultrasonic-welded CFRTP with the goal of evaluating the strength of the adhesive interface considering the combined shear and tensile stresses. One is a ‘compression shear test’, which evaluates the strength when compressive stress is applied in the shear direction to the adhesive interface. The other is a ‘flatwise test’, which evaluates the strength when tensile stress is applied perpendicular to the interface. Finite element analysis (FEM) is used to simulate both tests to obtain accurate shear and tensile stresses, taking into account the combined stress state and stress distribution. Based on the above results, a quantitative and comprehensive evaluation of adhesive strength at the welding interface is attempt. Keywords: CFRTP, Ultrasonic Welding, Shear test, Flatwise test, Paraboli criterion, Numerical simulation Fracture, Damage and Structural Health Monitoring Comprehensive Evaluation method of Bond Strength in Ultrasonic Welding for CFRTP Minori Isozaki a* , Maruri Takamura a , Shinichi Takeda b , and Jun Koyanagi c a Department of Materials Science and Technology, Graduatr School of Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125 8585, Japan b Japan Aerospace Exploraion Agency, 6-13-1 Oosawa Mitaka-shi Tokyo 181-0015, Japan c Department of Materials Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan Fracture, Damage and Structural Health Monitoring Comprehensive Evaluation method of Bond Strength in Ultrasonic Welding for CFRTP Minori Isozaki a* , Maruri Takamura a , Shinichi Takeda b , and Jun Koyanagi c a Department of Materials Science and Technology, Graduatr School of Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125 8585, Japan b Japan Aerospace Exploraion Agency, 6-13-1 Oosawa Mitaka-shi Tokyo 181-0015, Japan c Department of Materials Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan

Keywords: CFRTP, Ultrasonic Welding, Shear test, Flatwise test, Paraboli criterion, Numerical simulation

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 10.1016/j.prostr.2023.12.018 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 * Corresponding author. Tel.: +8190-6636-9309; fax: +81-3876-1411. E-mail address: 8219012@alumni.tus.ac.jp * Corresponding author. Tel.: +8190-6636-9309; fax: +81-3876-1411. E-mail address: 8219012@alumni.tus.ac.jp