Issue 41

S. K. Kourkoulis et alii, Frattura ed Integrità Strutturale, 41 (2017) 536-551; DOI: 10.3221/IGF-ESIS.41.64 536 Acoustic Emissions versus Pressure Stimulated Currents during bending of restored marble epistyles: Preliminary results Stavros K. Kourkoulis, Ioanna Dakanali, Ermioni D. Pasiou National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, 5 Heroes of Polytechnion Avenue, Theocaris Bld., Zografou Campus, 157 73 Athens, Greece stakkour@central.ntua.gr Ilias Stavrakas, Dimos Triantis Technological Educational Institution of Athens, Department of Electronics, Laboratory of Electronic Devices and Materials, Agiou Spiridonos Street, 122 10, Athens, Greece A BSTRACT . The efficiency of two modern sensing techniques, namely the “Acoustic Emissions” and the “Pressure Stimulated Currents” ones, when they are used as Continuous Structural Health Monitoring tools, is assessed experi- mentally. The protocol includes multi-point bending of an accurate copy of a fractured marble epistyle of the Parthenon’s Temple on the Acropolis of Athens, under a scale of 1:3. The integrity of the epistyle is restored with three pairs of bolted titanium bars, according to the pioneering technique developed by the scientists of the “Committee for the Conservation of the Acropolis Monuments”. The data provided by the above techniques are considered in juxtaposition to each other and also in comparison to data provided by the “Digital Image Correlation” technique. It is concluded that, at least from a qualitative point of view, the data of all three techniques are in good mutual agreement. Combined exploitation of the various sets of experimental data enlightens interesting aspects concerning the succession of failure mechanisms activated during the loading procedure, revealing the critical role of the internal interfaces characterizing the restored epistyle. Moreover it is definitely indicated that both the “Acoustic Emissions” and the “Pressure Stimulated Currents” techniques provide clear signs of upcoming failure well before macroscopically visible damages are detected at the external surface of the specimen. K EYWORDS . Acoustic Emissions; Pressure Stimulated Currents; Digital Image Correlation; Marble Monuments; Restoration/Conservation; Continuous Struc- tural Health Monitoring. Citation: Kourkoulis, S.K., Dakanali, I., Pa- siou, E.D., Stavrakas, I., Triantis, D., Acoustic Emissions versus Pressure Stimulated Currents during bending of restored marble epistyles: Preliminary results, Frattura ed Integrità Strutturale, 41 (2017) 536-551. 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.