TY - GEN
T1 - Modeling the influence of thermo-mechanical crack opening and closure on rock stiffness
AU - Zhu, C.
AU - Arson, C.
PY - 2013
Y1 - 2013
N2 - A thermodynamic framework is proposed to model the effect of mechanical stress and temperature on crack opening and closure in rocks. The model is based on Continuum Damage Mechanics with damage defined as the second-order crack density tensor. The free energy of damaged rock is expressed as a function of deformation, temperature and damage. The damage criterion controls mode I crack propagation, captures temperature-induced decrease of rock toughness, and accounts for the increase of energy release rate necessary to propagate cracks induced by damage. Crack closure is modeled through unilateral effects produced on rock stiffness. Simulations show that: (1) under anisotropic mechanical boundary conditions, crack closure occurs during cooling, (2) the thermo-mechanical strain energy necessary to close cracks during cooling is larger than the strain energy needed to close the cracks by mechanical compression. Parametric study highlights the thermo-mechanical stress redistributions occurring during closure. The proposed framework is expected to bring new insights in the design and reliability assessment of geotechnical reservoirs and repositories.
AB - A thermodynamic framework is proposed to model the effect of mechanical stress and temperature on crack opening and closure in rocks. The model is based on Continuum Damage Mechanics with damage defined as the second-order crack density tensor. The free energy of damaged rock is expressed as a function of deformation, temperature and damage. The damage criterion controls mode I crack propagation, captures temperature-induced decrease of rock toughness, and accounts for the increase of energy release rate necessary to propagate cracks induced by damage. Crack closure is modeled through unilateral effects produced on rock stiffness. Simulations show that: (1) under anisotropic mechanical boundary conditions, crack closure occurs during cooling, (2) the thermo-mechanical strain energy necessary to close cracks during cooling is larger than the strain energy needed to close the cracks by mechanical compression. Parametric study highlights the thermo-mechanical stress redistributions occurring during closure. The proposed framework is expected to bring new insights in the design and reliability assessment of geotechnical reservoirs and repositories.
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U2 - 10.1061/9780784412992.294
DO - 10.1061/9780784412992.294
M3 - Conference contribution
AN - SCOPUS:84887392105
SN - 9780784412992
T3 - Poromechanics V - Proceedings of the 5th Biot Conference on Poromechanics
SP - 2526
EP - 2535
BT - Poromechanics V - Proceedings of the 5th Biot Conference on Poromechanics
T2 - 5th Biot Conference on Poromechanics, BIOT 2013
Y2 - 10 July 2013 through 12 July 2013
ER -