PSI - Issue 33

ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceD rect Available online at www.sciencedirect.com ScienceDirect

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

Procedia Structural Integrity 33 (2021) 665–672

© 2021 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 IGF ExCo Abstract The use of adhesive bonds has increased significantly in recent years and is now a predominant bonding technique in the aeronautical and automotive industries. Cohesive Zone Models (CZM), used together with the Finite Element Method (FEM), are a viable tool to predict the strength ( P m ) of adhesive joints. The CZM combines strength criteria for damage initiation and fracture mechanics concepts for crack propagation. The main objective of this study is to numerically and experimentally evaluate the mechanical performance of adhesively-bonded stepped-lap joints with carbon-fiber reinforced plastic (CFRP) substrates under tensile loading. The influence of different overlap lengths ( L O ) and a ductile adhesive was also investigated. Experimental data was gathered and compared with numerical CZM results obtained using Abaqus ® . A study of peel (  y ) and shear (  xy ) stresses in the adhesive layer was performed. A significant geometry effect was found on the maximum load ( P m ) of the stepped-lap joints, with benefit for large L O ; however, delamination should be taken into account mostly for the longer L O . The CZM technique was revealed to be a suitable tool in determining the behavior of composite stepped-lap joints. © 2021 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 Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo Keywords: stepped-lap joint; cohesive-zone modeling; finite element method; adhesive joints; interlaminar damage of CFRP. 1. Introduction Stepped lap and scarf adhesive joints are commonly used for repairing aircraft panels because of the flush alignment between the substrates, reducing eccentric loading (da Silva et al., 2011). Although both stepped lap and scarf joints Abstract The use of adhesive bonds has increased significantly in recent years and is now a predominant bonding technique in the aeronautical nd autom tive industries. Cohesive Zo e Models (CZM), used together with the Finite Element Method (FEM), ar viable too to predict the strength ( P m ) of adhesive joints. The CZ combines strength cri eria for damag initiation and fractu mechanics concepts for crack propagati n. The main objective of this study i to nume ically an experimentally evaluate th al performance of adhesively-bonded stepped-lap joints with carbon-fiber reinforced plastic (CFRP) substrates under tensile loading. The i fluence of diff rent verlap l ngths ( L O ) a d a ductile adhes v was also investigated. Experiment l data was gathered nd compared with numerical CZM results obtained using Abaqus ® . A study of peel (  y ) and shear (  xy ) stresses in the adhesive layer was p rformed. A significant geometry effect wa found on the maximum load ( P m of the stepped-lap joints, with ben f t for large L O ; however, delami at on should be taken into cc t mostly for the longer L O . The CZM technique was revealed to b a suitable tool in d termining the behavi r of composite stepped-lap joints. © 2021 The Au hors. 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 Statement: Peer-revi w under responsibility of th scientifi committee of the IGF ExCo Keywords: stepped-lap joint; cohesive-zone modeling; finite element method; adhesive joints; interlaminar damage of CFRP. 1. Introduction Stepped lap and scarf adhesive joints are commonly used for repairing aircraft panels because of the flush alignment betw en the substrates, re ucing eccentric loading (da Silva et al., 2011). Although both stepped lap and scarf joints IGF26 - 26th International Conference on Fracture and Structural Integrity Composite stepped-lap adhesive joint analysis by cohesive zone modelling R.F.N. Brito a , R.D.S.G. Campilho a,b , R.D.F. Moreira a , I.J. Sánchez-Arce b *, F.J.G. Silva a,b a ISEP, Departamento de Engenharia Mecânica. Instituto Politécnico de Porto. Rua Dr. Bernardino de Almeida 431. 4200-072. Porto, Portugal. b INEGI, Pólo FEUP. Rua Dr. Roberto Frias 400. 4200-465. Porto, Portugal. IGF26 - 26th International Conference on Fracture and Structural Integrity Composite stepped-lap adhesive joint analysis by cohesive zone modelling R.F.N. Brito a , R.D.S.G. Campilho a,b , R.D.F. Moreira a , I.J. Sánchez-Arce b *, F.J.G. Silva a,b a ISEP, Departamento de Engenharia Mecânica. Instituto Politécnico de Porto. Rua Dr. Bernardino de Almeida 431. 4200-072. Porto, Portugal. b INEGI, Pólo FEUP. Rua Dr. Roberto Frias 400. 4200-465. Porto, Portugal.

* Corresponding author. Tel.: +351-912-414-207; fax: +351 229 537 352. E-mail address: isidrodjsa@gmail.com * Corresponding author. Tel.: +351-912-414-207; fax: +351 229 537 352. E-mail address: isidrodjsa@gmail.com

2452-3216 © 2021 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 Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo 2452-3216 © 2021 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 Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo

2452-3216 © 2021 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 IGF ExCo 10.1016/j.prostr.2021.10.074