Acoustic emission during slow crack growth : 2nd paper

Acoustic emission during slow crack growth : 2nd paper

Creators Sano Osamu

Creators Ogino Shoji

Creators Mizuta Yoshiaki

Double torsion testing was carried out for seven specimens of Oshima granite and Murata basalt. About 200 acoustic emissions for each rock were monitored and their wave forms were stored digitally by a transient event recorder. Fourier analysis was carried out for the first motion of each acoustic emission. In log-log plots, the relation between the power spectrum and the frequency could be regarded as two straight lines and the corner frequency was determined by the intersection of these lines. Acoustic emissions having high corner frequency had the lower maximum power spectrum. The maximum power spectrum increased with increasing stress intensity factor at the tip of the macrocrack. The corner frequency, in contrast, decreased with increasing stress intensity factor.

[ISSN]0386-3433

[NCID]AA0086073X