Dynamic strain localization into a compaction band via a phase-field approach

Journal of the Mechanics and Physics of Solids, Journal Year: 2023, Volume and Issue: 173, P. 105228 - 105228

Published: Feb. 2, 2023

We present a new phase-field formulation for the formation and propagation of compaction band in high-porosity rocks. Novel features proposed include (a) effects inertia on rate development bands, (b) degradation mechanisms tension, compression, shear appropriate dynamic strain localization problems where disturbances propagate time wave-like fashion to induce micro-cracking, grain crushing, frictional rearrangement rock. also robust numerical technique handle spatiotemporal evolution band. validate model by simulating benchmark problem involving V-shape notched cylindrical specimen Bentheim sandstone tested conventional triaxial compression. The is shown reproduce different geometric styles deformation that pure compaction, shear-enhanced combination mechanism consists straight primary surrounded secondary chevron bands.

Language: Английский

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State-of-the-art review on the use of AI-enhanced computational mechanics in geotechnical engineering

Artificial Intelligence Review, Journal Year: 2024, Volume and Issue: 57(8)

Published: July 5, 2024

Abstract Significant uncertainties can be found in the modelling of geotechnical materials. This attributed to complex behaviour soils and rocks amidst construction processes. Over past decades, field has increasingly embraced application artificial intelligence methodologies, thus recognising their suitability forecasting non-linear relationships intrinsic review offers a critical evaluation AI methodologies incorporated computational mechanics for engineering. The analysis categorises four pivotal areas: physical properties, mechanical constitutive models, other characteristics relevant Among various analysed, ANNs stand out as most commonly used strategy, while methods such SVMs, LSTMs, CNNs also see significant level application. widely algorithms are Artificial Neural Networks (ANN), Random Forest (RF), Support Vector Machines (SVM), representing 35%, 19%, 17% respectively. extensive is domain accounting 59%, followed by applications at 16%. efficacy intrinsically linked type datasets employed, selected model input. study outlines future research directions emphasising need integrate physically guided adaptive learning mechanisms enhance reliability adaptability addressing multi-scale multi-physics coupled problems geotechnics.

Language: Английский

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Impact of Water Saturation on the Anisotropic Elastic Moduli of a Gas Shale

Rock Mechanics and Rock Engineering, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 2, 2025

Abstract How water saturation affects elastic properties is particularly important for analyses of gas shales in unconventional reservoirs, but experimental data defined partially saturated conditions are rare. We show that the moduli a shale vary significantly with whereas static anisotropy does not. A series repeated hydrostatic compression were carried out on specimen at various states to determine ( $${E}_{\text{v}}$$ E v and $${E}_{\text{h}}$$ h ) as function degree $${S}_{\text{r}}$$ S r ). The calculated from reversible stress–strain curves after repeating confining pressure cycles. found that, while increases, peak intermediate then decreases minimum value quasi-saturation. This evolution may be explained by unifying two retention mechanisms, adsorption capillarity, have overall competing effects stiffness. It believed softens reducing friction load-bearing clay matrix, capillary menisci stiffen providing stabilizing forces. Young’s modulus $${E}_{\text{h}}/{E}_{\text{v}}$$ / did not appreciable change saturation. Confining seems more control changes anisotropy. Analyzing volumetric behavior reservoirs should take into account dependency. Extrapolating results in-situ must done great care.

Language: Английский

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Water retention behavior of a gas shale: Wettability-controlled water saturation and anisotropic hydromechanical response

International Journal of Rock Mechanics and Mining Sciences, Journal Year: 2025, Volume and Issue: 188, P. 106061 - 106061

Published: Feb. 23, 2025

Language: Английский

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A double-yield-surface plasticity theory for transversely isotropic rocks

Acta Geotechnica, Journal Year: 2022, Volume and Issue: 17(11), P. 5201 - 5221

Published: June 24, 2022

Language: Английский

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Influence of transient flow during infiltration and isotropic/anisotropic matric suction on the passive/active lateral earth pressures of partially saturated soils

Engineering Geology, Journal Year: 2022, Volume and Issue: 310, P. 106883 - 106883

Published: Oct. 12, 2022

Language: Английский

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Multiscale interactions of elastic anisotropy in unsaturated clayey rocks using a homogenization model

Acta Geotechnica, Journal Year: 2023, Volume and Issue: 18(5), P. 2289 - 2307

Published: Jan. 15, 2023

Language: Английский

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Solid–fluid interaction in porous materials with internal erosion

Acta Geotechnica, Journal Year: 2023, Volume and Issue: 18(10), P. 5147 - 5164

Published: June 1, 2023

Language: Английский

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Evolution of anisotropy with saturation and its implications for the elastoplastic responses of clay rocks

International Journal for Numerical and Analytical Methods in Geomechanics, Journal Year: 2021, Volume and Issue: 46(1), P. 23 - 46

Published: Nov. 2, 2021

Abstract Many clay rocks have distinct bedding planes. Experimental studies shown that their mechanical properties evolve with the degree of saturation (DOS), often higher stiffness and strength after drying. For transversely isotropic rocks, effects can differ between bed‐normal (BN) bed‐parallel (BP) directions, which gives rise to saturation‐dependent anisotropy. Accurate prediction behavior under partially saturated conditions requires numerical models capture evolving elastic plastic anisotropy DOS. In this study, we present an framework for coupled solid deformation‐fluid flow in unsaturated elastoplastic media. We incorporate into anisotropic modified Cam‐Clay (MCC) model consider both responses. The was calibrated using experimental data from triaxial tests demonstrate its capability capturing at various levels saturation. Through simulations, role rocks. Plane strain simulations compression were also conducted impacts material DOS on fluid

Language: Английский

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A phase‐field approach for compaction band formation due to grain crushing

International Journal for Numerical and Analytical Methods in Geomechanics, Journal Year: 2022, Volume and Issue: 46(16), P. 2965 - 2987

Published: Aug. 11, 2022

Abstract Compaction bands are tabular regions of localized compressive deformation with little or no shear offset. Often observed in high‐porosity rocks, they can be classified into several subtypes based on their pattern and orientation respect to the maximum principal stress. The combined effects material properties loading conditions type compaction that develop not fully understood, realistic simulations formation always successful. In this study, a phase‐field approach for capturing propagation is proposed. fracture energy utilized classic formulations interpreted driven by grain crushing herein characterized breakage mechanics theory. A new decomposition free function introduced which stored plastic compactive flow drives crushing. Depending value release rate, model predicts different styles remarkably consistent those field. Numerical demonstrate role confining pressure, plasticity, critical predicted bands.

Language: Английский

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