000021873 001__ 21873
000021873 005__ 20170622131309.0
000021873 04107 $$aeng
000021873 046__ $$k2017-06-15
000021873 100__ $$aEbrahimian, Ziba
000021873 24500 $$aSECONDARY ACOUSTIC EMISSIONS IN STRESSED ROCKS

000021873 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000021873 260__ $$bNational Technical University of Athens, 2017
000021873 506__ $$arestricted
000021873 520__ $$2eng$$aWithin the past few decades, different studies have been conducted to examine frequency characteristics of Acoustic Emissions (AEs) due to the loading stress on rocks. Ohanka ( [1], [2] ) conducted a few experiments on stressed rocks and observed AEs in different frequency bands ranging from a few hundred hertz to over 1 MHz. While in these observations in some cases the emissions from the same events presented time and phase difference (Figure 2b and 2d of [1]), the cause remained unexplained. In the present study, a theory is given to explain the phase and time difference between the related acoustic emission signals. The theory proposes that the delayed propagated AE wave with lower frequency components is due to the widening of the existing crack. The result is utilized to propose explanations for other related lab and field observations, including simultaneous increase in the event rates in differing frequency bands of the AE signals (Figure 3a and 4a of [1], and 5a, 6a, 7a, and 8a of [2]). The theory is also exploited to describe the frequency range difference between seismology, micro-seismic, and acoustic emission measurements (shown in Figure 1 of [3]). 

000021873 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000021873 653__ $$a

000021873 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000021873 720__ $$aEbrahimian, Ziba
000021873 8560_ $$ffischerc@itam.cas.cz
000021873 8564_ $$s116636$$uhttps://invenio.itam.cas.cz/record/21873/files/18185.pdf$$yOriginal version of the author's contribution as presented on CD, section: [MS17] Computational issues in earthquake engineering
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000021873 962__ $$r21500
000021873 980__ $$aPAPER