PSI - Issue 33

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 vailable online at .sciencedirect.co i i t Structural Integrity Procedia 00 (2019) 000 – 000

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Procedia Structural Integrity 33 (2021) 330–336

© 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 The acoustic activity detected during mechanical loading of notched marble plates under mode-I conditions is studied. Attention is paid at the very last loading steps, i.e., when fracture is impending. The specimens were made of Dionysos marble. In each specimen two edge notches were mechanically machined normally to the loading axis. Four classes of specimens were tested, depending on the length (depth) of the two notches. The specimens were loaded quasi-statically under displacement control conditions. The acoustic activity is analyzed in terms of the cumulative number of counts of the acoustic emission hits. It is concluded that, in terms of the specific parameter and while fracture is impending, the acoustic activity is governed by a power law, quite similar to the one governing the respective evolution of the F-function and, also, the res pective evolution of the electric activity within the specimen’s volume. 2 he 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 Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo Keywords: Acoustic emissions, Pressure Stimulated Currents, F-function, Marble, Double Edge Notched Tensile Specimens, Direct Tension 1. Introduction The present study is part of a wider protocol aiming to explore the mechanisms activated while natural building stones are loaded mechanically at levels tending to exhaust their load-carrying capacity and, simultaneously, to detect bstract The acoustic activity detected during echanical loading of notched arble plates under ode-I conditions is studied. ttention is paid at the very last loading steps, i.e., hen fracture is i pending. The speci ens ere ade of ionysos arble. In each speci en t o edge notches ere echanically achined nor ally to the loading axis. Four classes of speci ens ere tested, depending on the length (depth) of the t o notches. The speci ens ere loaded quasi-statically under displace ent control conditions. The acoustic activity is analyzed in ter s of the cu ulative nu ber of counts of the acoustic e ission hits. It is concluded that, in ter s of the specific para eter and hile fracture is i pending, the acoustic activity is governed by a po er la , quite si ilar to the one governing the respective evolution of the F-function and, also, the res pective evolution of the electric activity ithin the speci en’s volu e. 1 The uthors. Published by ELSE IE . . s is an open access article under the - - license (https://creativeco ons.org/licenses/by-nc-nd/4.0) -revie State ent: Peer-revie under responsibility of the scientific co ittee of the I F Ex o Keywords: coustic e issions, Pressure Sti ulated Currents, F-function, arble, ouble Edge otched Tensile Speci ens, irect Tension 1. Introduction he present study is part of a ider protocol ai ing to explore the echanis s activated hile natural building stones are loaded echanically at levels tending to exhaust their load-carrying capacity and, si ultaneously, to detect IGF26 - 26th International Conference on Fracture and Structural Integrity Exploring the acoustic activity in marble specimens under tension while entering into the stage of impending fracture Dimos Triantis a , Ilias Stavrakas a , Andronikos Loukidis a , Ermioni D. Pasiou b , Stavros K. Kourkoulis b * a University of West Attica, School of Engineering, Department of Electrical and Electronic Engineering, Electronic Devices and Materials Laboratory, Athens, Greece b National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, Laboratory for Testing and Materials, Athens, Greece - t I ter ati al fere ce ract re a tr ct ral I te rit l i t ti ti it i l i t i il t i i t t t i i t i s ri tis a , Ili s t r s a , r i s i is a , Er i i . si b , t r s . r lis b a niversity of est Attica, School of Engineering, epart ent of Electrical and Electronic Engineering, Electronic evices and aterials Laboratory, Athens, reece b National Technical niversity of Athens, School of Applied athe atical and Physical Sciences, epart ent of echanics, Laboratory for Testing and aterials, Athens, reece I

* Corresponding author. Tel.: +30-210-7721263; fax: +30-210-7721302. E-mail address: stakkour@central.ntua.gr * Corresponding author. Tel.: +30-210-7721263; fax: +30-210-7721302. E- ail address: stakkour central.ntua.gr

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 Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo 2452-3216 2021 The uthors. Published by ELSE IER B. . This is an open access article under the CC B - C- license (https://creativeco ons.org/licenses/by-nc-nd/4.0) Peer-revie State ent: Peer-revie under responsibility of the scientific co ittee of the I F ExCo

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.2021.10.040