An apparatus for investigating the elastic anisotropy on spherical rock samples

Influence of thermal heating on elastic wave velocities in granulite

“…P-wave velocity measurements were carried out under laboratory conditions using the pulse transmission technique and two electro-acoustic transducers [23]. The technique has been modified for spherical specimens, 50 mm70.01 mm in diameter, investigated by equipment designed for ultrasonic sounding of rock specimens [24] at required confining pressures [20]. The equipment consists of a pressure vessel connected to a two-step pressure generator, a specimen positioning unit equipped with a pair of ultrasonic piezo-ceramic transducers (transmitter and receiver), a device for generating ultrasonic pulses and traveltime measurement and a data acquisition unit.…”

Laboratory measurement of elastic anisotropy on spherical rock samples by longitudinal and transverse sounding under confining pressure

“…The study of the velocity anisotropy of V P on spherical samples provides more complete information of the velocities in any direction both under atmospheric and high hydrostatic pressures [21][22][23][24][25][26][27][28].…”

3C laboratory measurement using laser interferometer

“…The velocities are determined from traveltimes of waves generated and recorded by ultrasonic piezoelectric transducers (e.g. Pros and Babuska, 1967;Jech, 1991;Rasolofosaon and Zinszner, 2002). Despite great advantage of implementations of piezoelectric transducers as sources and receivers in ultrasonics, there are at least two problems with this kind of experiments, namely, 1) uncertainty in determination of the time of shear wave arrivals, and 2) uncertainty of whether phase or group velocity is measured.…”