Issue 40

K. Kaklis et alii, Frattura ed Integrità Strutturale, 40 (2017) 1-17; DOI: 10.3221/IGF-ESIS.40.01 1 Focussed on Recent advances in “Experimental Mechanics of Materials” in Greece Using acoustic emissions to enhance fracture toughness calculations for CCNBD marble specimens K. Kaklis, S. Mavrigiannakis School of Mineral Resources Eng., Technical Univ. of Crete, Greece kaklis@mred.tuc.gr , smaurig@mred.tuc.gr V. Saltas, F. Vallianatos Dept Environmental and Natural Res. Eng., Tech. Educational Institute of Crete, Greece vsaltas@chania.teicrete.gr , fvallian@chania.teicrete.gr Z. Agioutantis Department of Mining Engineering, University of Kentucky, Lexington, KY, USA zach.agioutantis@uky.edu A BSTRACT . Rock fracture mechanics has been widely applied to blasting, hydraulic fracturing, mechanical fragmentation, rock slope analysis, geophysics, earthquake mechanics and many other science and technology fields. Development of failure in brittle materials is associated with microcracks, which release energy in the form of elastic waves called acoustic emissions. In the present study, acoustic emission (AE) measurements were carried out during cracked chevron notched Brazilian disc (CCNBD) tests on Nestos marble specimens. The fracture toughness of different modes of loading (mode-I and –II) is calculated and the results are discussed in conjunction with the AE parameters. K EYWORDS . Rock fracture toughness; Mode I loading; CCNBD; Acoustic emissions; Marble. Citation: Kaklis, K., Saltas, V., Mavrigiannakis, S., Valiannatos, F., Agioutantis, Z., Using acoustic emissions to enhance fracture toughness calculations for CCNBD marble specimens, Frattura ed Integrità Strutturale, 40 (2017) 1-17. Received: 11.07.2016 Accepted: 12.09.2016 Published: 01.04.2017 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. I NTRODUCTION racture mechanics can be applied to many engineering fields including civil and mining engineering, where drilling, excavation, explosion and cutting of rocks are closely related to the strength, stability and fracture of rock materials and structures. Fracture toughness represents the ability of a material to resist the propagation of cracks; it is considered to be an inherent property of each material and should not be related to testing conditions. F