Issue 41

M.F. Funari et alii, Frattura ed Integrità Strutturale, 41 (2017) 524-535; DOI: 10.3221/IGF-ESIS.41.63 524 Dynamic debonding in layered structures: a coupled ALE-cohesive approach Marco Francesco Funari, Fabrizio Greco, Paolo Lonetti Department of Civil Engineering, University of Calabria, Via P. Bucci, Cubo39B, 87030, Rende, Cosenza, Italy marcofrancesco.funari@unical.it, https://orcid.org/0000-0001-9928-3036 fabrizio.greco@unical.it, https://orcid.org/0000-0001-9423-4964 paolo.lonetti@unical.it, https://orcid.org/0000-0003-0678-6860 A BSTRACT . A computational formulation able to simulate crack initiation and growth in layered structural systems is proposed. In order to identify the position of the onset interfacial defects and their dynamic debonding mechanisms, a moving mesh strategy, based on Arbitrary Lagrangian-Eulerian (ALE) approach, is combined with a cohesive interface methodology, in which weak based moving connections are implemented by using a finite element formulation. The numerical formulation has been implemented by means of separate steps, concerned, at first, to identify the correct position of the crack onset and, subsequently, the growth by changing the computational geometry of the interfaces. In order to verify the accuracy and to validate the proposed methodology, comparisons with experimental and numerical results are developed. In particular, results, in terms of location and speed of the debonding front, obtained by the proposed model, are compared with the ones arising from the literature. Moreover, a parametric study in terms of geometrical characteristics of the layered structure are developed. The investigation reveals the impact of the stiffening of the reinforced strip and of adhesive thickness on the dynamic debonding mechanisms. K EYWORDS . Debonding; ALE; Dynamic Delamination; FEM; Crack Onset. Citation: Funari, M. F., Greco, F., Lonetti, P., Dynamic debonding in layered structures: a coupled ALE-cohesive approach, Frattura ed Integrità Strutturale, 41 (2017) 524-535. Received: 30.04.2017 Accepted: 31.05.2017 Published: 01.07.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION uring the last decades, layered structures in the form of laminates or thin films have employed extensively in many engineering fields, ranging from nano to macro scale applications. Typically, such materials are formed by strong layers and weak interfaces, in which internal material discontinuities may evolve, producing relevant loss of stiffness [1]. Moreover, the crack evolution is strongly affected by the time rate of the external loading, which typically produces high amplifications of the fracture parameters. As a matter of fact, the measured crack tip speeds, during crack propagation, are relatively high, ranging also close to the Rayleigh wave speed of the material [2,3]. Therefore, in order to predict the interfacial crack growth, models developed also in a dynamic framework are much required. D