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Numerical modelling of heat shock‐assisted rock fracture
Author(s) -
Pressacco Martina,
Saksala Timo
Publication year - 2020
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.3004
Subject(s) - discontinuity (linguistics) , shock (circulatory) , thermal shock , compressive strength , comminution , finite element method , mechanics , fracture (geology) , constitutive equation , materials science , compression (physics) , numerical analysis , geotechnical engineering , structural engineering , geology , mathematics , composite material , engineering , physics , mathematical analysis , metallurgy , medicine
Summary This paper presents a numerical investigation on the effects of thermal shock as a pretreatment of rock prior to comminution. More specifically, the effect of heat shock‐induced cracks on the uniaxial compressive strength of rock is numerically studied. The chosen constitutive model of rock employs a (strong) embedded discontinuity finite element formulation to describe cracks. The thermomechanical problem that governs the heat shock pretreatment of rocks is considered as an uncoupled problem because of a highly dominating role of the external heat influx. Two solution methods of the global problem are presented: an explicit‐explicit dynamic scheme and an implicit‐implicit quasi‐static scheme. The model performance is tested in simulations on heterogeneous numerical rock samples subjected first to a heat shock pretreatment and then to a mechanical compression test. According to the results, the compressive strength of intact granite rock having the axial splitting failure mode can be substantially reduced by heat shock pretreatment.