EFFECT OF STATIC AND DYNAMIC LOADING ON STRENGTH AND Q-FACTOR RELATIONSHIP

In real mines, rocks are exposed to both static and dynamic forces, for instance, under blasting. This article discusses lab-scale testing of strength of marmorized limestone samples from the Perevalnoe deposit, Republic of Dagestan, subjected to quasi-static and dynamic loading. The curves of strength and force impact in the form of load–relief cycles and blowing are obtained. The relationship between the acoustic Q-factor and strength is determined for both regimes of loading. The dynamic testing plant included the split Hopkinson pressure bars made of granite. The mentioned curves are approximated by the logarithmic function σst = 87,99 ∙ ln(Q) – 96,53 with the coefficient of determination R2 = 0.99 under the quasi-static testing and by the exponential function σdyn = 30,56 ∙ e0,11 ∙ Qwith R2 = 0.84 in case of the dynamic testing. Under the quasi-static loading, as the attacks are increased in number, the non-monotonous change is observed both in the strength and acoustic Q-factor of the samples. Under the dynamic loading, both values decrease.


This study was supported by the Russian Foundation of Basic Research and the R&D supporting fund for students, post-graduate students and young scientists—National Intelligent Development, Project No. 17-35-80028 mol_ev_a.

Keywords

Аcoustic Q-factor, strength, quasi-static loading, dynamic loading, split Hopkinson pressure bars, marmorized limestone.

Issue number: 12
Year: 2018
ISBN:
UDK: 622.831:550.3
DOI: 10.25018/0236-1493-2018-12-0-127-133
Authors: Kutkin Ya. O., Krasilov M. N., Nasibullin R. R., Tyutcheva A. O.

About authors: Kutkin Ya.O., Candidate of Technical Sciences, Assistant Professor, e-mail: kutnew@mail.ru, Krasilov M.N., Assistant of Chair, e-mail: krasilov.maksim.93@mail.ru, Nasibullin R.R., Student, e-mail: ram4ik10@mail.ru, Tyutcheva A.O., Student, e-mail: 9295947810@mail.ru, National University of Science and Technology «MISiS», 119049, Moscow, Russia.

REFERENCES:

1. Keshavarz M., Pellet F. L., Loret B. Damage and Changes in Mechanical Properties of a Gabbro Thermally Loaded up to 1,000 °C. Pure and Applied Geophysics. 167. 2010. Pp. 1511—1523.

2. Voznesenskii A. S., KutkinYa.O., Krasilov M. N. Interrelation of the acoustic Q-factor and strength in limestone. Journal of Mining Science. 2015, January. Vol. 51. Issue 1. Pp. 23—30.

3. Lebedev A. V., Ostrovskiy L. A., Sutin A. M., Soustova I. A., Dzhonson P. A. Rezonansnaya akusticheskaya spektroskopiya pri nizkikh dobrotnostyakh [Acoustic resonance spectroscopy under low Q-factors], Akusticheskiy zhurnal. 2003, vol. 49, no 1, pp. 92—99. [In Russ].

4. Voznesenskii A. S., Krasilov M. N., KutkinYa.O., Tavostin M. N., Osipov Yu. V. Features of interrelations between acoustic quality factor and strength of rock salt during fatigue cyclic loadings. International Journal of Fatigue. 2017. Vol. 97. Pp. 70—76.

5. Kutkin Ya. O., Krasilov M. N., Nasibullin R. R. Ustanovka dlya izucheniya svoystv gornykh porod pri dinamicheskikh vozdeystviyakh [Dynamic testing plant to study properties of rocks], Gornyy informatsionno-analiticheskiy byulleten’. 2017, no 12, pp. 146—152. [In Russ].

6. Hopkinson B. A method of measuring the pressure produced in the detonation of high explosives or by the impact of bullets. Phil. Trans. R. Soc. Lond. A 213. Pp. 437—456. DOI: 10.1098/rsta.1914.0010.

7. Kolsky H. An investigation of mechanical properties at very high rates of loading. Proceeding of the Physics Society of London. B62. 1949. Pp. 676—700.

8. Zhao J., Wu W., Zhang Q. B., Sun L. Some recent developments on rock dynamic experiments and modeling. Rock Dynamics and Applications State of the Art. London, 2013. Pp. 25—40.

9. Voznesenskii A. S., Kutkin Ya. O., Krasilov M. N., Komissarov A. A. Predicting fatigue strength of rocks by its interrelation with the acoustic quality factor. International Journal of Fatigue. 2015. Vol. 77. Pp. 186—193.

10. Ivanova V. S., Terent'ev V. F. Priroda ustalosti metallov [Nature of metal fatigue], Moscow, Metallurgiya, 1975, 456 p.

11. Terent'ev V. F. Ustalost' metallicheskikh materialov [Fatigue of metallic materials], Moscow, Nauka, 2002, 248 p.

12. Terent'ev V. F., Oksogoev A. A. Tsiklicheskaya prochnost' metallicheskikh materialov [Cyclical strength of metallic materials], Novosibirsk, Izd-vo NGTU, 2001, 61 p.

Mining World Russia
Subscribe for our dispatch