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Understanding Acoustic Emission Testing- Reading 1 Part B-A

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16.7.1 Fracture Mechanics Studies<br />

A number of studies have shown that acoustic emission can be related to<br />

crack growth or fracture mechanics parameters in cements, mortars, and<br />

concretes. Evans et al. showed that acoustic emission could be correlated<br />

with crack velocity in mortars. Morita and Kato and Nadeau, Bennett, and<br />

Mindess were able to relate total acoustic emission counts to Kc (the fracture<br />

toughness). In addition, Lenain and Bunsell found that the number of<br />

emissions could be related to the sixth power of the stress intensity factor, K.<br />

(K 6 ?) Izumi et al. showed that acoustic emissions could also be related to the<br />

strain energy release rate, G. In all cases, however, these correlations are<br />

purely empirical; no one has yet developed a fundamental relationship<br />

between acoustic emission events and fracture parameters, and it is unlikely<br />

that such a relationship exists.<br />

Charlie Chong/ Fion Zhang

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