PSI - Issue 54

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ScienceDirect

Procedia Structural Integrity 54 (2024) 164–171 Structural Integrity Procedia 00 (2023) 000–000 Structural Integrity Procedia 00 (2023) 000–000

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 the scientific committee of the ICSI 2023 organizers Abstract The increasing trend of using adhesive to bond primary structures in marine applications requires an in-depth understanding of the behaviour of these joints under fatigue loading. This paper describes a test method to determine the fatigue crack growth rate for double cantilever beam specimens with a thick adhesive bondline. The strain energy release rate at the crack tip during testing is calculated using the Kanninen-Penado model which takes the thickness and the sti ff ness of the adhesive layer into account. The model parameters are verified using digital image correlation and are shown to be valid for an asymmetric DCB specimen with an initial crack at the adhesive-adherend interface. © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers. Keywords: Fatigue crack growth rate; Thick bondline; Interface characterisation; Adhesive bonding In recent years, the International Maritime Organisation has resolved to reduce greenhouse gas emissions by at least 50% by 2050 (Marine Environmental Protection Committee, 2018). To achieve this goal, one of the proposals of the marine industry is to replace metals such as steel and aluminium with composite sandwich panels in the primary structures of a ship. This helps to reduce displacement tonnage while retaining strength; a 10% reduction in weight is expected to reduce fuel consumption by almost 7% and consequently reduce the emission of greenhouse gases (Interreg 2 Seas). However, the use of dissimilar materials necessitates the use of adhesives over mechanical fasteners such as bolts and rivets due to a higher strength-to-weight ratio and lower stress concentration in adhesive joints (Delzendehrooy et al., 2022; Hashim, 1999). Although adhesive bonding has been extensively adopted in the aerospace and automotive sectors, its application in the marine industry has been limited to secondary structures, which are neither load-carrying nor critical to the ship’s operation in case of failure (Zuo and Vassilopoulos, 2020). This is due to the fact that in aerospace and automobile applications thin bondline adhesive joints are manufactured in a closely controlled environment. Additionally, the adherend surfaces are extensively pre-treated before bonding and International Conference on Structural Integrity 2023 (ICSI 2023) Development of Test Method for Fatigue Crack Growth using DCB Specimens with Thick Adhesive Bondline Rahul Iyer Kumar a, ∗ , Wim De Waele a a Soete Laboratory, Department of Electromechanical, Systems and Metal Engineering, Technologiepark-Zwijnaarde 46, 9052 Gent, Belgium Abstract The increasing trend of using adhesive to bond primary structures in marine applications requires an in-depth understanding of the behaviour of these joints under fatigue loading. This paper describes a test method to determine the fatigue crack growth rate for double cantilever beam specimens with a thick adhesive bondline. The strain energy release rate at the crack tip during testing is calculated using the Kanninen-Penado model which takes the thickness and the sti ff ness of the adhesive layer into account. The model parameters are verified using digital image correlation and are shown to be valid for an asymmetric DCB specimen with an initial crack at the adhesive-adherend interface. © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers. Keywords: Fatigue crack growth rate; Thick bondline; Interface characterisation; Adhesive bonding 1. Introduction In recent years, the International Maritime Organisation has resolved to reduce greenhouse gas emissions by at least 50% by 2050 (Marine Environmental Protection Committee, 2018). To achieve this goal, one of the proposals of the marine industry is to replace metals such as steel and aluminium with composite sandwich panels in the primary structures of a ship. This helps to reduce displacement tonnage while retaining strength; a 10% reduction in weight is expected to reduce fuel consumption by almost 7% and consequently reduce the emission of greenhouse gases (Interreg 2 Seas). However, the use of dissimilar materials necessitates the use of adhesives over mechanical fasteners such as bolts and rivets due to a higher strength-to-weight ratio and lower stress concentration in adhesive joints (Delzendehrooy et al., 2022; Hashim, 1999). Although adhesive bonding has been extensively adopted in the aerospace and automotive sectors, its application in the marine industry has been limited to secondary structures, which are neither load-carrying nor critical to the ship’s operation in case of failure (Zuo and Vassilopoulos, 2020). This is due to the fact that in aerospace and automobile applications thin bondline adhesive joints are manufactured in a closely controlled environment. Additionally, the adherend surfaces are extensively pre-treated before bonding and International Conference on Structural Integrity 2023 (ICSI 2023) Development of Test Method for Fatigue Crack Growth using DCB Specimens with Thick Adhesive Bondline Rahul Iyer Kumar a, ∗ , Wim De Waele a a Soete Laboratory, Department of Electromechanical, Systems and Metal Engineering, Technologiepark-Zwijnaarde 46, 9052 Gent, Belgium 1. Introduction

∗ Corresponding author E-mail address: Rahul.IyerKumar@UGent.be ∗ Corresponding author E-mail address: Rahul.IyerKumar@UGent.be

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 the scientific committee of the ICSI 2023 organizers 10.1016/j.prostr.2024.01.069 2210-7843 © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers. 2210-7843 © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers.