LABORATORY SETUP FOR ULTRASONIC TESTING OF ROCK SAMPLES IN VARIABLE TEMPERATURE AND PRESSURE CONDITIONS
A description of a laboratory setup for ultrasonic measurements on rock samples and artificial materials subjected to varying temperature and pressure is given. The setup consists of three main units: a thermal unit designed to heat and maintain a predetermined temperature of the sample under study, a unit of uniaxial mechanical loading and an ultrasonic measurement unit. The design of the thermal unit is based on the use of semiconductor thermoelectric converters (TEC) based on the Peltier effect. The use of the latter allows the sample to be heated directly under the loading machine, while achieving relatively low inertia and level of acoustic noise. The temperature level is controlled by a closed feedback loop using thermistors located between the TEC and the surface of the heated sample. For effective heat exchange of TEC with the environment, combined water-air cooling is used. The thermal unit is controlled manually using a potentiometer block, or by means of control commands from a PC via the USB interface. Commercially available compact press GT 2.0.8-2 used as a mechanical loading unit. The ultrasonic measurement unit consists of a probe pulse generator, an ADC with a sampling frequency of up to 10 MHz, a pair of acoustic transducers with a resonant frequency of 500 kHz and a personal computer. The unit provides automatic determination of elastic waves propagation speed in samples, their spectral and energy characteristics in varying temperature and pressure conditions.
Acknowledgements: This work was done with the financial support of the Russian Foundation for Basic Research (project No. 19-05-00152\19).
For citation: Nikolenko P. V., Shkuratnik V. L. Laboratory setup for ultrasonic testing of rock samples in variable temperature and pressure conditions. Gornyy informatsionno-analiticheskiy byulleten'. 2019;5:89-96. [In Russ]. DOI: 10.25018/0236-1493-2019-05-0-89-96.
: Nikolenko P. V., Shkuratnik V. L.
P.V. Nikolenko, Candidate of Technical Sciences, Assistant Professor,
V.L. Shkuratnik, Doctor of Technical Sciences, Professor,
National University of Science and Technology «MISiS»,
119049, Moscow, Russia.
Corresponding author: V.L. Shkuratnik, e-mail: firstname.lastname@example.org.Key words
Laboratory setup, thermobaric effects, rock samples, Peltier effect, ultrasound, control, stress state.References
1. Pervukhina M., Gurevich B., Dewhurst D. N., Siggins A. F. Applicability of velocity—stress relationships based on the dual porosity concept to isotropic porous rocks. Geophysical Journal International, 2010, Vol. 181, no 3, pp. 1473—1479.
2. Lokajíček T., Svitek T., Petružálek M. Laboratory approach to the study of dynamic and static bulk anisotropy in rock under high hydrostatic pressure by simultaneous P. S sounding and sample deformation measurements on spheres. 48th US Rock Mechanics Geomechanics Symposium, 2014, Vol. 2, pp. 988—994.
3. Pimienta L., Fortin J., Guéguen Y. Bulk modulus dispersion and attenuation in sandstones.
Geophysics, 2015, Vol. 80, no 2, pp. 111—127.
4. Shkuratnik V. L., Nikolenko P. V., Koshelev A. E. Stress dependence of elastic p-wave velocity and amplitude in coal specimens under varied loading conditions. Journal of Mining Science, 2016, Vol. 52. no 5. pp. 873—877.
5. Wei X., Wang S.-X., Zhao J.-G., Tang G.-Y., Deng J.-X. Laboratory study of velocity dispersion of the seismic wave in fluid-saturated sandstones. Chinese Journal of Geophysics (Acta Geophysica Sinica), 2015, Vol. 58, no 9, pp. 3380—3388.
6. Li S. H., Zhu W. C., Niu L. L., Yu M., Chen C. F. Dynamic Characteristics of Green Sandstone Subjected to Repetitive Impact Loading: Phenomena and Mechanisms. Rock Mechanics and Rock Engineering, 2018, Vol. 51, no 6, pp. 1921—1936.
7. Nikolenko P. V., Chepur M. D. Methods and technical solutions for estimation of dynamics of the stress-strain state of the rock massif based on acoustic emission effects in composite materials. Gornyy informatsionno-analiticheskiy byulleten’. 2018, no 12, pp. 134—141. [In Russ].
8. Shkuratnik V. L., Nikolenko P. V., Kormnov A. A. Ultrasonic correlation logging for roof rock structure diagnostics. Journal of Mining Science, 2015, Vol. 51, no 3. pp. 456—461.
9. Nazarov L. A. Determination of structured rock mass properties by acoustic method. Fizikotekhnicheskiye problemy razrabotki poleznykh iskopayemykh. 1999, no 3, pp. 36—44. [In Russ].
10. Feng Z., Mingjie X., Zhonggao M., Liang C., Zhu Z., Juan L. An experimental study on the correlation between the elastic wave velocity and microfractures in coal rock from the Qingshui basin. Journal of Geophysics and Engineering, 2012, Vol. 9, no 6, pp. 691—696.
11. Volarovich M. P. The investigation of elastic and absorption properties of rocks at high pressures and temperatures. Tectonophysics, 1965, Vol. 2, no 2—3, pp. 211—217.
12. Ostadhassan M., Tamimi N. Mechanical behavior of salt rock at elevated temperature.
48th US Rock Mechanics Geomechanics Symposium, 2014, Vol. 3, pp. 1473—1480.
13. Chryssanthakis P., Westerdahl H., Rose E., Rhett D., Pederson S. High temperature triaxial tests with ultrasonic measurements on Ekofisk chalk. 20th Century Lessons, 21st Century Challenges, 1999, pp. 573—578.
14. Abdulagatova Z. Z., Emirov S., Abdulagatov I. M. Effect of temperature and pressure on thermal conductivity and sound velocity in andesitic rocks. Ul'trazvuk i termodinamicheskie svoystva veshchestva. 2006, no 33, pp. 5—23. [In Russ].
15. Disalvo F. J. Thermoelectric cooling and power generation. Science, 1999, Vol. 285, no 5428, pp. 703—706.