Flat problem to determine the forces of destruction of pieces n disintegrators while being grabbed in thick layer

User Rating:  / 0
PoorBest 

Authors:


O.O.Tytov, orcid.org/0000-0001-6794-8240, Dnipro University of Technology, Dnipro, Ukraine, email: This email address is being protected from spambots. You need JavaScript enabled to view it.

V.P.Nadutyy, orcid.org/0000-0002-2453-0351, Institute of Geotechnical Mechanics named by N.Poljakov, Dnipro, Ukraine

K.V.Babii, orcid.org/0000-0002-0733-2732, Institute of Geotechnical Mechanics named by N.Poljakov, Dnipro, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

D.L.Kolosov, orcid.org/0000-0003-0585-5908, Dnipro University of Technology, Dnipro, Ukraine, email: This email address is being protected from spambots. You need JavaScript enabled to view it.

V.Yu.Kukhar, orcid.org/0000-0002-1849-4489, Dnipro University of Technology, Dnipro, Ukraine, email: This email address is being protected from spambots. You need JavaScript enabled to view it.


повний текст / full article



Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2022, (3): 067 - 075

https://doi.org/10.33271/nvngu/2022-3/067



Abstract:



Purpose. Research on analytical dependences of destructive stresses, acting on a piece of non-isometric shape at quasi-static deformation of a relatively thick layer of rock mass in disintegrators, on parameters of the piece shape, the pieces spatial orientation, also on the relative piece size in layer, taking into consideration the discrete nature of contact force application.


Methodology. The flat scheme of a non-isometric shaped piece contacts in a thick layer of rock mass is obtained by composition of the central rectangular piece and the round pieces of average size for the given layer. The distribution of stress components in the layer of loose rock mass is accepted on the basis of the classical theory of elasticity and the theory of loose medium. The geomechanics criterion showing relationship of equivalent destructive stress and ultimate compressive strength of rock is used as a criterion of piece destruction in complex stress state. All force schemes of the piece loading are reduced to three-point bending schemes and two-point shear schemes, both across the long and the short sides of the piece. The most dangerous loading scheme is determined from the analysis of the mentioned schemes for each particular case. Dimensionless parameterization is applied both to specify the geometric parameters of pieces and to analyze the resulting destructive stresses.


Findings. Analytical dependences of equivalent destructive stresses for an oblong piece are obtained depending on the piece relative length, the relative piece size in the rock layer, the angle of piece orientation relative to the direction of the maximum main stress and the side thrust coefficient in the layer. It has been set that lamellar pieces, especially those smaller than the average size for the layer, are destroyed mainly from the implementation of bending schemes across the long side, the shape of their fragments is improved by reducing the pieces relative length. Increasing the uniformity of the force field in the working zone of disintegrator also leads to improvement in the shape of fragments. On the other hand, as the shape of the piece approaches the isometric one, as well as when the piece relative size in layer raises, the probability of implementing shear schemes increases and the probability of implementing bending schemes decreases, including with a deterioration in the fragments shape compared to the original piece. At the same time, larger values of destructive stresses for the lamellar smaller pieces are proved analytically compared to the isometric bigger ones, all other things being equal.


Originality. The versatility of application of the three-point bending scheme of a non-isometric shaped piece in combination with the two-point scheme of its shear for analysis of its destruction in the thick layer of rock mass is substantiated. For the first time, the dependences of equivalent destructive stresses for the non-isometric piece on its relative length, its relative size in layer, the angle of deviation of the pieces main axis from the main stress direction and on the side thrust coefficient in the layer have been obtained.


Practical value. The results obtained allow making reasonable choice of parameters of disintegrators operational parts for destruction of materials in the thick layer, as well as predicting the change in lamellar pieces fraction during disintegration process. They give the possibility to determine key parameters of operational parts for new designs of disintegrators. This creates the basis for the development of calculation techniques for operational parts of modern samples of crushing and grinding equipment.



Keywords: disintegrator, thick layer, complex stress state, lamellar piece, bend, shear, side thrust coefficient

References.


1. Bozhyk, D.P., Sokur, M.I., Biletskii, V.S., Shevchuk, Yu.V., & Sokur, I.M. (2017). Research o the state and development of production of cotstructiot materials from natural building stone. Zbahachennia korysnykh kopalyn, naukovo-tekhn. zbirnyk, 68(109), 3-12.

2. Sokur, M.I., Biletskii, V.S., Vedmid, I.A., & Robota, Ye.M. (2020). Ore preparation (crushing, grinding, classification): monograph. Kremenchutskyi Natsionalnyi Universytet im. M.Ostrohradskoho, Akademiia Hyrnychykh Nauk Ukrainy: PP ShcherbatykhO.V., Kremenchuk.

3. Sokur, M.I., Biletskii, V.S., Yehurnov, O.I., Vorobyov, O.M., Smyrnov, V.O., & Bozhyk, D.P. (2017). Preparation of minerals for enrichment: monograph. Kremenchutskyi Natsionalnyi Universytet im. M.Ostrohradskoho, Akademiia Hyrnychykh Nauk Ukrainy: PP ShcherbatykhO.V., Kremenchuk.

4. Nadutyi, V., Tytov, O., & Cheberiachko, I. (2018). Hereditary model of loose mined rock layer deformation in disintegrators. E3S Web of Conferences, Ukrainian School of Mining Engineering, 60, 00033. https://doi.org/10.1051/e3sconf/20186000033.

5. Solona, O.V. (2020). Controlled vibrating mill for grinding bulk medium. Vibratsii v tekhnitsi ta tekhnolohiiakh, 4(99), 11-20.

6. Belmas,I., Kogut,P., Kolosov,D., Samusia, V., & Onyshchenko,S. (2019). Rigidity of elastic shell of rubber-cable belt during displacement of cables relatively to drum.International Conference Essays of Mining Science and Practice,109, 00005. https://doi.org/10.1051/e3sconf/201910900005.

7. Ilin, S., Adorska, L., Samusia, V., Kolosov, D., & Ilina, I. (2019). Conceptual bases of intensification of mining operations in mines of Ukraine based on monitoring and condition management of mine hoisting systems. International Conference Essays of Mining Science and Practice, 109, 00030. https://doi.org/10.1051/e3sconf/201910900030.

8. Babets, D., Sdvyzhkova, O., Shashenko, O., Kravchenko, K., & Cabana,E.C. (2019). Implementation of probabilistic approach to rock mass strength estimation while excavating through fault zones, Mining of Mineral Deposits, 13(4), 72-83. https://doi.org/10.33271/mining13.04.072.

9. Sdvyzhkova, ., Golovko, Y., Dubytska, M., & Klymenko, D. (2016). Studying a crack initiation in terms of elastic oscillations in stress strain rock mass, Mining of Mineral Deposits,10(2),72-77.

10. Pryadko, N.C., & Ternovaya, E.V. (2016). Controlled vibrating mill for grinding bulk medium. Tekhnicheskaya Mekhanika, (4), 104-111.

11. Nadutyi, V.P., Tytov, O.O., Kolosov, D.L., & Sukhariev, V.V. (2020). Influence of particles geometry on the efficiency of operation of quasistatic and inertial disintegrators, Naukovyi Visnyk Natsionalnoho Hirnychoho Iniversytetu, (6), 21-27. https://doi.org/10.33271/nvngu/2020-6/021.

12.Efimov, V.P. (2016). Determination of tensile strength of rocks based on the results of testing disk samples with a central hole. Fiziko-tekhnicheskie problemy razrabotki poleznykh iskopaemykh, 5, 54-60.

 

Visitors

4861833
Today
This Month
All days
776
61933
4861833

Guest Book

If you have questions, comments or suggestions, you can write them in our "Guest Book"

Registration data

ISSN (print) 2071-2227,
ISSN (online) 2223-2362.
Journal was registered by Ministry of Justice of Ukraine.
Registration number КВ No.17742-6592PR dated April 27, 2011.

Contacts

D.Yavornytskyi ave.,19, pavilion 3, room 24-а, Dnipro, 49005
Tel.: +38 (056) 746 32 79.
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
You are here: Home Authors and readers terms of subscription EngCat Archive 2022 Content №3 2022 Flat problem to determine the forces of destruction of pieces n disintegrators while being grabbed in thick layer