PSI - Issue 41

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

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Procedia Structural Integrity 41 (2022) 94–102

2nd Mediterranean Conference on Fracture and Structural Integrity Inhomogeneous beam structures of rectangular cross-section loaded in torsion: a delamination study with considering creep

Victor Rizov* Department of Technical Mechanics, University of Architecture, Civil Engineering and Geodesy, 1 Chr. Smirnensky blvd., 1046 – Sofia, Bulgaria

© 2022 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 MedFract2Guest Editors. Abstract This paper describes a delamination study of inhomogeneous beam structure with rectangular cross-section subjected to torsion. The beam exhibits linear creep behaviour. The beam is built-up by two longitudinal vertical layers of different width. The layers are continuously inhomogeneous along the beam length. The delamination crack is located inside the beam between layers. The torsion moments in the crack arms are obtained by treating of the beam as internally statically undetermined structure with one degree of indeterminacy. For this purpose, the theorem of Menabrea is applied (the torsion moment in the left-hand crack arm is considered as a redundant unknown). Solution of the strain energy release rate is derived by considering the strain energy in the beam. The strain energy release rate is function of time due to creep behaviour. For verification of the solution, the strain energy release rate is found also by considering the beam compliance. A parametric study is developed. © 2022 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 MedFract2Guest Editors. Keywords: Inhomogeneous material; Creep behavior; Rectangular beam structure; Delamintion; Torsion 1. Introduction Many structural materials used in modern engineering constructions exhibit continuous inhomogeneity of their properties. The material inhomogeneity can be in one or more directions in the solid. The big group of inhomogeneous materials include various composite materials. In the recent decades, a special class of continuously

* 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 © 2022 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 MedFract2Guest Editors.

2452-3216 © 2022 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 MedFract2Guest Editors. 10.1016/j.prostr.2022.05.012