Caracterización de daño por “b-value” de eventos de emisión acústica en ensayos de rotura de roca andesita

AUTOR(ES)
FONTE

Matéria (Rio J.)

DATA DE PUBLICAÇÃO

19/07/2018

RESUMO

ABSTRACT Acoustic emission is a phenomenon that produces elastic waves when materials are subjected to tension. These waves spread towards the material surface where they are received by sensors that convert them into electrical signals for further analysis. In this work, acoustic emission signals were analysed in order to evaluate the amount of accumulated damage in a material when it is subjected to tensions that make it to fracture. The Gutenberg-Richter law predicts a potential behaviour, given by b-value, between the cumulative number of acoustic emission events and the amplitude of them. Taking account of acoustic emission signals obtained in previous works, in andesite samples subjected to uniaxial compression up to break, an analysis of the progress of b-value was done in order to characterize the material damage occurred. A b-value of b = 1.105 was obtained with a good correlation coefficient of 0.995. The value obtained from the b-value is the expected value that ranges between 0.5 and 1.5. The analysis of the signals allowed to correlate the change of the b-value with the relative maximum values of the acoustic emission parameters.

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