PSI - Issue 25

Available online at www.sciencedirect.com

ScienceDirect

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

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 25 (2020) 88–100

© 2020 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 VCSI1 organizers An analysis of the influence of the viscoelastic behaviour of the material on the delamination fracture in multilayered beam structures subjected to creep is carried-out. The fracture is studied in terms of the strain energy release rate. For this purpose, an approach for calculation of the strain energy release rate by analyzing the energy balance in the beams is developed. Four viscoelastic models consisting of combinations of linear dashpots and springs for a constant applied stress are used for treating the creep behaviour. The approach is applied to analyze the strain energy release rate in a multilayered cantilever beam with a delamination crack subjected to creep. The analysis indicates that the creep leads to increase of the strain energy release rate. The effects of the ratios of coefficients of viscosity and the moduli of elasticity in the beam layers on the delamination fracture behaviour are evaluated by using the four viscoelastic models. © 2020 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the VCSI1 organizers 1st Virtual Conference on Structural Integrity - VCSI1 Influence of the viscoelastic material behaviour on the delamination in multilayered beam Victor Rizov* Department of Technical Mechanics, University of Architecture, Civil Engineering and Geodesy, 1 Chr. Smirnensky blvd., 1046 – Sofia, Bulgaria Abstract

Keywords: Multilayered beam; Delamination crack; Viscoelestic material; Creep; Fracture; Linear rheological models

1. Introduction

Multilayered materials and structural components are made of adhesively bonded layers of different materials. The application of multilayered materials in various load-bearing structures in the present-day engineering has been widely attempted to achieve reduction of the structural weight. One of the basic disadvantages of multilayered structural members and components is their tendency to delaminate. Delamination, or separation of layers,

* Corresponding author. Tel.: + (359-2) 963 52 45 / 664; fax: + (359-2) 86 56 863. E-mail address: V_RIZOV_FHE@UACG.BG

2452-3216 © 2020 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 VCSI1 organizers

2452-3216 © 2020 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 VCSI1 organizers 10.1016/j.prostr.2020.04.013