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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.44 [2006] >
IJPAP Vol.44(11) [November 2006] >
| Title: | Amplitude distribution analysis of acoustic emissions and investigation of the development of brittle fracture in rock |
| Authors: | Rao, M V M S
Lakshmi, K J Prasanna |
| Keywords: | Microcracking
AE b-value
Rock fracture
Fractals |
| Issue Date: | Nov-2006 |
| Publisher: | CSIR |
| IPC Code: | G10K11/16 |
| Abstract: | Materials undergoing brittle failure produce
large number of acoustic emissions (AE) of varying amplitudes. The most useful
way to describe and analyse the AE amplitude distribution is by computing the b-value (slope of the log-linear
frequency-magnitude distribution of AE). Conventionally, the b-value of AE is calculated using the
methods adopted in seismology since many similarities exist between AE and
seismic waves. The b-value is usually
obtained either from the cumulative frequency distribution or the discrete
frequency distribution of earthquake magnitudes and the same principles hold
good for the AE data also. We have carried out the AE amplitude distribution
analysis using advanced software (Mistras-2001) and computed the AE b-value using the Gutenberg-Richter
relationship for the cumulative frequency distribution data and Aki’s method
for the discrete distribution data. The results obtained by both these methods
to evaluate the fracture process in a granite rock are compared and discussed
as a case study in this paper. Useful inferences about the fractal distribution
of crack lengths leading to the dynamic failure of the test rock could also be
obtained using the AE b-value data. |
| Page(s): | 820-825 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.44(11) [November 2006]
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