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Experimental investigation and micromechanics-based constitutive modeling of the transition from brittle to ductile behavior in saturated low-porosity rocks.
- Source :
-
Applied Mathematical Modelling . Feb2024, Vol. 126, p506-525. 20p. - Publication Year :
- 2024
-
Abstract
- This paper presents a unified experimental and numerical investigation on the transition from brittle to ductile behavior in a low-porosity sandstone under drained conditions. The experimental results demonstrate a transition in the mechanical behavior from brittle faulting to dilatant ductile flow at room temperature with an increase in effective confining pressure, suggesting that microcracking-controlled local friction is the underlying plastic deformation mechanism. For constitutive modeling, the sandstone is considered as a heterogeneous medium composed of a pores-weakened elastic solid matrix and distributed microcracks. By following a two-step homogenization procedure and irreversible thermodynamics framework, a micromechanics-based elastoplastic damage model incorporating a non-associated local plastic flow rule is formulated, in which the coupling between plasticity, damage and pore pressure is taken into account. In this context, a non-associated macroscopic effective strength criterion as an inherent part of the corresponding model is derived. Originally, a theoretical linear relation between critical state of damage at peak strength and effective confining pressure is established, which is efficient in describing post-peak softening behavior. Comparisons of numerical simulations with experimental data demonstrate that the proposed model effectively reproduces the main features of the sandstone with a brittle-ductile transition. • A transition from brittle to ductile behavior in a saturated low-porosity sandstone is observed. • A non-associated micromechanics-based constitutive model is developed. • A non-associated macroscopic effective strength criterion is derived. • A linear relation between critical damage and effective confining pressure is established. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0307904X
- Volume :
- 126
- Database :
- Academic Search Index
- Journal :
- Applied Mathematical Modelling
- Publication Type :
- Academic Journal
- Accession number :
- 174104143
- Full Text :
- https://doi.org/10.1016/j.apm.2023.11.014