Podrobnosti záznamu

Název
    Determination of the anisotropy of elastic waves monitored by a sparse sensor network
Autor
    Lokajíček, Tomáš
    Petružálek, Matěj
    Rudajev, Vladimír
    Svitek, Tomáš
    Vilhelm, J.
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    International Journal of Rock Mechanics and Mining Sciences
Svazek/č.
    Roč. 60, June
Strany
    s. 208-216
Rok
    2013
Poznámky
    Projekt: GAP104/12/0915, GA ČR, CZ3cav_un_auth*0288140
    Rozsah: 9 s. : E
Předmětová kategorie
    acoustic emission
    anisotropy
    seismic velocity
    ultrasonic transmission
    velocity ellipsoid
Klíčové slovo
    Anisotropy
    Determination
    Elastic
    Monitored
    Network
    Sensor
    Sparse
    Waves
Abstrakt (anglicky)
   A method of velocity anisotropy analysis based on conventional ultrasonic transmission technique is proposed. Multiple transducers are used both to monitor acoustic emission and to measure velocities in different propagation directions. A sparse network of transducers located on the rock core surface allows approximation of elastic waves velocity distribution as an ellipsoidal surface. The shape and orientation of velocity ellipsoid is a measure of velocity anisotropy.A study of changes in velocity anisotropy and its orientation was performed on uniaxially loaded migmatite rock samples with distinct foliation. The velocity measurement was carried out during applying a uniaxial constant strain-rate loading. Orientation of the velocity ellipsoid corresponded to the anisotropy of rock structure up to activation of a failure plane.
   Prior to brittle failure, the axis of minimum velocity rotated from its initial direction normal to the foliation to a direction normal to the failure surface.The practical importance of the ellipsoid model lies in its simplicity and in its general applicability, which allows the use of measurement in a sparse sensor network. The use of time-variable ellipsoidal velocity model led to a better localization of acoustic emission events during the sample loading when compared to the use of time-variable isotropic velocity model. The position of the failure plane determined by clustering of acoustic events foci coincided closely with observed sample failure.
Přispěvatel
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
    U
Datum importu
    23. 10. 2014