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Failure mechanism in porous materials under compression: crackling noise in mesoporous SiO2 |
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| Authors: | Ekhard KH Salje Daniel Enrique Soto-Parra Antoni Planes Eduard Vives Marius Reinecker Wilfried Schranz |
| Institution: | 1. Department of Earth Sciences , University of Cambridge, Downing Street , Cambridge CB2 3EQ, United Kingdom ekhard@esc.cam.ac.uk;3. Departament d’Estructura i Constituents de la Matèria, Facultat de Física , Universitat de Barcelona, Diagonal 647 , Barcelona 08028, Catalonia, Spain;4. Faculty of Physics , University of Viena, Boltzmanngasse 5 , Vienna A-1090, Austria |
| Abstract: | The failure mechanism of porous materials under uniaxial stress has been investigated experimentally. Microporous SiO2, Vycor, has been subjected to slowly increasing compressive uniaxial stress with stress rates between 0.2 and 12.2?kPa/s. With increasing stress the strain changes stepwise with acoustic emission correlated with each volume collapse. The acoustic emission followed the characteristics of ‘crackling noise’ with a power law distribution over an exceptionally large interval of 6 decades at the slowest stress rate. The power law exponent is ?1.39. Possible applications in mining industry and others are discussed. |
| Keywords: | crackling noise cracking mechanical testing porous media silicates |