PSI - Issue 66

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 66 (2024) 282–286

8th International Conference on Crack Paths A simple method for designing adhesive single lap joints G. Cricrì, F. Penta* Università degli Studi di Napoli Federico II, Dept. of Industrial Engineering, p.le V. Tecchio n°80, 80125, Naples, ITALY

Abstract Present paper covers the analysis of adhesive-bonded single lap joints by means of the cohesive crack modelling technique. A closed form solution, describing the appearance and growth of cracks in the adhesive layer is presented. The presented theoretical results give an insight on how the main failure criteria adopted for designing the single lap joints may be reconciliated by the cohesive crack approach. More specifically, for very short joint a critical stress criterion may be adopted, being the adhesive shear stress distribution nearly uniform. Instead, the value of the maximum joint strength, attained for very long joints, is derivable by the Griffith fracture criterion. The field of applicability of the proposed model has been analysed by means of a validation study carried out by the results of a family of 2D finite element joint models. © 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 CP 2024 Organizers Keywords: Bonded joints, Cohesive crack models; Structural adhesive; Lap-joint design. 1. Introduction Designing adhesive lap joints is an intriguing issue and a challenging task, because their behaviour is influenced by many mechanical and geometrical parameters including adherends and adhesive stiffness, adhesive constitutive properties and geometry, manufacturing process, etc. Many models have been proposed for their analysis. They have been extensively reviewed in the papers of Tserpes et al. (2022) and da Silva et al. (2009). Unfortunately, none of the existing models seems be able to effectively support the joint engineer during the first stages of the design, since most of them are based or on over-simplifying assumptions, or on a very accurate description of the adhesive behaviour. The first approach neglects some critical aspects of the problem; on the other hand, to implement any accurate joint © 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 CP 2024 Organizers

* Corresponding author. Tel.: +39 081 768 2451; mob: +39 347 6080 985. E-mail address: penta@unina.it

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 CP 2024 Organizers

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 CP 2024 Organizers 10.1016/j.prostr.2024.11.077