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Discrete element modeling of tool‐rock interaction II: rock indentation
Author(s) -
Huang Haiying,
Detournay Emmanuel
Publication year - 2013
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2114
Subject(s) - indentation , brittleness , discrete element method , wedge (geometry) , fracture toughness , geology , stress field , geotechnical engineering , rock mechanics , materials science , fracture (geology) , finite element method , structural engineering , mechanics , geometry , composite material , engineering , mathematics , physics
SUMMARY The failure mechanisms induced by a wedge‐shaped tool indenting normally against a rock surface are investigated using the discrete element method (DEM). The main focus of this study is to explore the conditions controlling the transition from a ductile to a brittle mode of failure. The development of a damage zone and the initiation and propagation of a brittle fracture is well captured by the DEM simulations. The numerical results support the conjecture that initiation of brittle fractures is governed by a scaled flaw length Λ, a ratio between the flaw size λ and the characteristic length ℓ =K Ic ∕ σ c2(where K Ic is the toughness and σ c the uniaxial compressive strength). The size of the damage zone agrees well with analytical predictions based on the cavity expansion model. The effects of a far‐field confining stress and the existence of a relief surface near the indenter are also examined.Copyright © 2012 John Wiley & Sons, Ltd.