PSI - Issue 33

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 il l li t . i i t. tr t r l I t rit r i ( )

www.elsevier.com/locate/procedia . l i r. /l t / r i

ScienceDirect

Procedia Structural Integrity 33 (2021) 416–427

IGF26 - 26th International Conference on Fracture and Structural Integrity

© 2021 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 scientific committee of the IGF ExCo Abstract This paper analyzes the effect of strain recovery upon unloading on longitudinal fracture behaviour of continuously inhomogeneous beam with linear creep. For this purpose, time-dependent solutions to the strain energy release rate are obtained for both loading and unloading phases by using the strain energy. Time-dependent solutions to the strain energy release rate are found also by considering the compliance of the beam for verification. The creep is treated by using a linear viscoelastic model. The material is continuously inhomogeneous in both thickness and length directions of the beam. Therefore, the modulii of elasticity and the coefficient of viscosity are continuously distributed along the thickness and length of the beam. The longitudinal crack is located symmetrically with respect to the mid-span. Due to the symmetry, only half of the beam is analyzed. A parametric investigation of the time-dependent longitudinal fracture behaviour of the beam is carried-out by applying the solutions to the strain energy release rate. The variation of the strain energy release rate with time due to the creep behaviour in loading and unloading phases is investigated. © 2020 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 European Structural Integrity Society (ESIS) ExCo Keywords: Inhomogeneous rod; Longitudinal fracture; Material non-linearity; Torsion i l t t t i l i l it i l t i ti l i it li . t i , ti t l ti t t t i l t t i t l i l i i t t i . i t l ti t t t i l t l i i t li t i i ti . i t t i li i l ti t i l i ti l i i t t i l t i ti t . , t l i l ti it t i i t i it ti l i t i t l t t i l t t . l it i l i l t t i l it t t t i . t t t , l l t i l t i i ti ti t ti t l it i l t i t i i t l i t l ti t t t i l t . i ti t t i l t it ti t t i i l i l i i i ti t . 2 2 T ut o . Pu lished y EL EVI .V. his is n pen cce s ticle u der the C -ND lice s ( t s: / ti . /li / / . i i ilit t t t l t it i t : I r ; it i l fr t r ; t ri l -li rit ; r i Effects of strain recovery on longitudinal fracture in continuously inhomogeneous viscoelastic beams Victor Rizov* Department of Technical Mechanics, University of Architecture, Civil Engineering and Geodesy, 1 Chr. Smirnensky blvd., 1046 – Sofia, Bulgaria t t f i l i , i it f it t , i il i i , . i l ., fi , l i

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1. Introduction The development and advance in various areas of modern engineering requires application of new and effective . i l t i i i i i li ti ti

* Corresponding author. Tel.: + (359-2) 963 52 45 / 664; fax: + (359-2) 86 56 863. E-mail address: v_rizov_fhe@uacg.bg r i t r. l.: ( - ) / ; f : ( - ) - il : ri f .

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2452-3216 © 2020 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 European Structural Integrity Society (ESIS) ExCo - t r . li I . . i i rti l r t - - li ( t : / r ti . r /li / - - / . ) r-r i r r i ilit f t r tr t r l I t rit i t ( I )

2452-3216 © 2021 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 scientific committee of the IGF ExCo 10.1016/j.prostr.2021.10.049