PSI - Issue 72

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ScienceDirect

Procedia Structural Integrity 72 (2025) 105–112

12th Annual Conference of Society for Structural Integrity and Life (DIVK12) An extended sandwich model for structural integrity analysis of adhesive bondings Thomas Steffen Methfessel a , Wilfried Becker b, * a MTU Aero Engines AG, Dachauer Str. 665, 80995 München, Germany b Technical University of Darmstadt, Institute of Applied Dynamics, Otto-Berndt-Str. 2, 64287 Darmstadt, Germany Abstract In many situations adhesive bonding is very advantageous to join load-carrying components without the use of screws or rivets and with a load transfer distributed over a larger overlapping area. In these situations, the actual structural analysis, however, is quite demanding since local stress concentrations occur at the edges of the joints, which may lead to the onset of debonding cracks and subsequent failure. The current contribution suggests a so-called sandwich model for the overlap region with a closed-form higher order description of the adhesive layer and the potential occurrence of a debonding crack. By use of the principle of minimum total potential energy a set of differential equations is derived that allows a closed-form description for the resultant deformation of the underlying structural configuration. This enables a highly efficient prediction of the corresponding stress distribution within the adhesive bonding and the assessment of structural integrity by the concept of Finite Fracture Mechanics. The comparison with accompanying finite element calculations and experimental findings reveals the high predictive quality of this approach. © 2026 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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia

Keywords: Adhesive joint; sandwich model; higher-order approach; Finite Fracture Mechanics

1. Introduction In many fields of structural mechanics, the use of adhesive bonding is a well-established joining technique, for instance in light-weight construction, mechanical engineering or civil engineering. This technique is particularly

* Corresponding author. Tel.: +49-6151-1626140 E-mail address: becker@fsm.tu-darmstadt.de

2452-3216 © 2026 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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia 10.1016/j.prostr.2025.08.080