Rock dynamic indentation is the most basic form of rock dynamic fragmentation, understanding the rock failure mechanism and influence factors of breaking efficiency plays important roles in improving impact drilling efficiency. According to the research achievements of Marshall, the theoretical model of radial crack and lateral crack length considering confining pressure and hydraulic pressure was established, analyzing the influence of confining pressure, hydraulic pressure on crack propagation, and the influence of loading rate on rock fragmentation effect. In addition, the discrete element numerical simulation method was used to study the characteristics of crack formation and propagation and the influence of loading rate on breaking effect under spherical tooth dynamic indentation. The results indicate that theoretical analysis and numerical simulation results are basically identical, with the increase of dynamic load, the damaged area and lateral crack growth, and radial crack initiates from the damaged area and propagates towards the rock free surface, forming rock fragments eventually; under the same dynamic load amplitude and duration, the increase of confining pressure has an inhibitory effect on damaged area, lateral crack, and radial crack, the increase of hydraulic pressure has a promoting effect on damaged area and lateral crack but has an inhibitory effect on radial crack; under the same dynamic load amplitude, rock breaking volume first increases and then decreases with the duration shortening, and when the dynamic load amplitude is 8.5 kN, duration is 1.25 ms, the crushing volume is the largest. The research achievements of this paper can provide reference for understanding dynamic fragmentation mechanism and improving impact drilling efficiency.
This is a preview of subscription content, log in to check access.
Buy single article
Instant unlimited access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Akbari B, Butt SD, Munaswamy K et al (2011) Dynamic single PDC cutter rock drilling modeling and simulations focusing on rate of penetration using distinct element method. ARMA-11-379
Alehossein H, Detournay E, Huang H (2000) An analytical model for the indentation of rocks by blunt tools. Rock Mech Rock Eng 33(4):267–284
Chen LH, Labuz JF (2006) Indentation of rock by wedge-shaped tools. Int J Rock Mech Min Sci 43(7):1023–1033
Eftekhari M, Baghbanan A, Bagherpour R (2014) The effect of fracture patterns on penetration rate of TBM in fractured rock mass using probabilistic numerical approach. Arab J Geosci 7(12):5321–5331
Evans AG, Wilshaw TR (1977) Dynamic solid particle damage in brittle materials: an appraisal. J Mater Sci 12(1):97–116
Haeri H, Marji MF (2016) Simulating the crack propagation and cracks coalescence underneathTBM disc cutters. Arab J Geosci 9(2):124
Hou B, Chang Z, Fu WN, Muhadasi Y, Chen M (2019) Fracture initiation and propagation in a deep shale gas reservoir subject to an alternating-fluid-injection hydraulic-fracturing treatment. Soc Pet Eng. https://doi.org/10.2118/195571-PA
Huang HY, Detournay E (2013) Discrete element modeling of tool-rock interaction II: rock indentation. Int J Numer Anal Methods Geomech 37(13):1930–1947
Huang H, Damjanac B, Detournay E (1998) Normal wedge indentation in rocks with lateral confinement. Rock Mech Rock Eng 31(2):81–94
Lawn BR, Evans AG (1977) A model for crack initiation in elastic/plastic indentation fields. J Mater Sci 12(11):2195–2199
Lawn BR, Swain MV (1975) Microfracture beneath point indentations in brittle solids. J Mater Sci 10(1):113–122
Lawn BR, Wilshaw TR (1975) Indentation fracture: principles and applications. J Mater Sci 10(6):1049–1081
Li XB (2014) Rock dynamics fundamentals and applications. Science Press, Beijing, pp 176–200
Li XF, Li HB, Liu YQ et al (2016) Numerical simulation of rock fragmentation mechanisms subject to wedge penetration for TBMs. Tunn Undergr Space Technol 53:96–108
Liu HY, Kou SQ, Lindqyist PA et al (2002) Numerical simulation of the rock fragmentation process induced by indenters. Int J Rock Mech Min Sci 39(4):491–505
Marshall DB (1984a) Geometrical effects in elastic/plastic indentation. J Am Ceram Soc 67(1):57–60
Marshall DB (1984b) Measurement of dynamic hardness by controlled sharp projectile impact effects in elastic/plastic indentation. J Am Ceram Soc 67(1):580–585
Marshall DB, Lawn BR, Evans AG (1982) Elastic/plastic indentation damage in ceramics: the lateral crack system. J Am Ceram Soc 65(11):561–566
Potyondy DO (2004) A bonded-particle model for rock. Int J Rock Mech Min Sci 41(8):1329–1364
Souissi S, Hamdi E, Sellami H (2015) Microstructure effect on hard rock damage and fracture during indentation process. Geotech Geol Eng 33(6):1539–1550
Tan Q, Zhang K, Zhou ZL et al (2010) Numerical simulation and experimental observation of rock cracks under action of spherical tooth hob cutting. Chin J Rock Mech Eng 29(1):163–169
Tan Q, Xu ZJ, Xia YM et al (2013) Numerical simulation of dynamic response mechanism of rock by shield machine cutters. Chin J Geotech Eng 35(2):235–242
Zhang ZX, Kou SQ (1990) On rock fracture under static and dynamic indentations. J Univ Sci Technol Beijing 12(5):401–407
Zhang ZX, Kou SQ (1992) Some new progress in indentation problem of solid mechanics. Adv Mech 22(2):183–193
Zhang H, Huang G, Song H et al (2012) Experimental investigation of deformation and failure mechanisms in rock under indentation by digital image correlation. Eng Fract Mech 96:667–675
Zhang H, Song H, Kang Y et al (2013) Experimental analysis on deformation evolution and crack propagation of rock under cyclic indentation. Rock Mech Rock Eng 46(5):1053–1059
Zhu HC (2006) PFC and application case of caving study. Chin J Rock Mech Eng 25(9):1927–1931
The authors are grateful for the Project Supported by the National Natural Science Foundation of China (No. 51804047 and No. 41672133) and the National Science and Technology Major Project-Horizontal well fracturing design optimization system (No. 2016ZX05023-001).
Responsible Editor: Liang Xiao
About this article
Cite this article
Deng, Y., Yin, F., Deng, H. et al. Research on crack propagation and rock fragmentation efficiency under spherical tooth dynamic indentation. Arab J Geosci 13, 30 (2020). https://doi.org/10.1007/s12517-019-4926-7
- Dynamic indentation
- Crack propagation
- Loading rate
- Rock breaking
- Discrete element