Combination of digital image processing and random generation in modeling soil-rock mixture slopes for post-failure analyses by material point method

Computers and Geotechnics, Journal Year: 2023, Volume and Issue: 165, P. 105886 - 105886

Published: Oct. 30, 2023

Language: Английский

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A novel unresolved/semi‐resolved CFD‐DEM coupling method with dynamic unstructured mesh

International Journal for Numerical and Analytical Methods in Geomechanics, Journal Year: 2024, Volume and Issue: 48(7), P. 1774 - 1796

Published: Feb. 15, 2024

Abstract The greatest challenge when performing large deformation simulations using the CFD‐DEM coupling method lies in dynamical update of fluid meshes. To address this problem, a novel integrated with dynamic unstructured grid is proposed work. mesh initialization and reconstruction are performed by Constrained Delaunay triangulation (CDT) implemented tetgen algorithm. Moreover, equation state (EOS) introduced to consider impact compressibility. reliability preliminarily verified particle sedimentation test. Additionally, undrained triaxial shear one‐dimensional consolidation tests conducted examine applicability simulating geotechnical cases. From our analysis, it found that responses test obtained from direct accordance those led constant volume (CV) method. However, difficulties arise accurately describing moving boundary fixed mesh, leading unreliable results. test, both grids can capture Mandel—Cryer effect, which more pronounced under grid, mainly due dual loading device skeleton on fluid. A greater compressibility specified weakening whereas its duration increased. Our work provides valuable insights for effectively dealing boundaries.

Language: Английский

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An improved corner dealiasing and recognition algorithm for 2D Wadell roundness computation

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: April 24, 2024

This paper optimizes the 2D Wadell roundness calculation of particles based on digital image processing methods. An algorithm for grouping corner key points is proposed to distinguish each independent corner. Additionally, cyclic midpoint filtering method introduced dealiasing, aiming mitigate aliasing issues effectively. The relationships between number pixels (m), central angle (α) and parameter dealiasing degree (n) are established. Krumbein chart a sandstone thin section were used as examples calculate roundness. A set regular shapes calculated, error this discussed. When α ≥ 30°, maximum 5.21%; when 12° ≤ < increases. By applying interpolation increase minimum (m

Language: Английский

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CFD-DEM modeling of seepage in foam-conditioned soil

Computers and Geotechnics, Journal Year: 2024, Volume and Issue: 177, P. 106818 - 106818

Published: Oct. 9, 2024

Language: Английский

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A hybrid resolved CFD-DEM study on internal erosion in gap-graded soils considering coarse particle shape

Computers and Geotechnics, Journal Year: 2025, Volume and Issue: 183, P. 107204 - 107204

Published: March 17, 2025

Language: Английский

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A novel liquid–gas–solid computational fluid dynamics-discrete element method-volume of fluid coupling method with compressible fluid phases

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(4)

Published: April 1, 2025

Traditional computational fluid dynamics (CFD)-discrete element method (DEM)-volume of (VOF) three-phase coupling methods may produce inaccurate results in certain scenarios due to the assumption incompressible liquid and gas phases. In this study, a novel CFD-DEM-VOF is proposed, which integrates unified equation state account for compressibility both The α transport derived, fractional step proposed solving equation. Additionally, continuity incorporating coefficients derived used influence during pressure correction. algorithm validated through simulations three classic cases: single particle entering water from air, dam break, entry block. Moreover, unsaturated soil loading problems are investigated using method. indicate that liquid–gas interface begins rise only when deep soil, saturated with liquid, experiences significant disturbance. A comparison excess pore movement velocities particles two monitoring mesh layers below initial level reflects spatial response patterns under external loading. Finally, coefficient discussed.

Language: Английский

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Micromechanical modeling of triphasic granular media

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(18)

Published: May 2, 2025

This paper presents pore unit assembly-discrete element model (PUA-DEM), a pore-scale hydromechanical framework that resolves interactions between mobile granular particles and multiphase fluids in unsaturated media. The uniquely integrates DEM with hydrodynamic models to capture flow dynamics, while leveraging two-way coupling mechanism ensure bidirectional fluid–grain feedback through stabilized domain partitioning. Further innovations include dynamic pore-merging retriangulation algorithm enhances computational efficiency for large-scale systems. Validated against experimental data glass beads Ottawa sand, PUA-DEM accurately reproduces critical phenomena-including capillary/viscous fingering, wetting-induced swelling/collapse, quasi-static deformation-under diverse saturation loading regimes. Numerical case studies reveal how capillary forces wetting fluid collectively govern response, from meniscus evolution macroscale instabilities. By bridging pore- particle-scale physics, advances predictive modeling of partially saturated systems, offering transformative insights geohazard mitigation, sustainable agriculture, pharmaceutical manufacturing, energy-related engineering applications.

Language: Английский

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Randomly generating realistic calcareous sand for directional seepage simulation using deep convolutional generative adversarial networks

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

Published: May 1, 2025

Language: Английский

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A novel update criterion of Verlet list for accelerating DEM computation when modeling geotechnical dense granular materials under periodic loading

Computational Particle Mechanics, Journal Year: 2025, Volume and Issue: unknown

Published: June 5, 2025

Language: Английский

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Numerical investigation of the instability of dry granular bed induced by water leakage

Acta Geotechnica, Journal Year: 2024, Volume and Issue: 19(5), P. 3229 - 3239

Published: Feb. 8, 2024

Abstract Underground pipe defects or cracks under transport infrastructure can cause water leakage to upper soil layers (e.g. subgrade and capping), inducing local cavities even failure of overlying road/railway formation. Although numerous studies on the instability granular beds induced by injected have been conducted, most them focused behaviour saturated beds, while research dry is still limited. This paper aims address this gap using a numerical model coupling volume fluid method with discrete element method. We observed that go through three distinct regimes as jet velocity increases including stationary, stable deformation heave fluidisation. However, flow velocities required deform fluidise are significantly higher than those for beds. Increasing bed thickness alter its mechanism from full depth localised erosion, leading cavity formation around prior The gravitational frictional components mass identified two main resisting forces against force, evidenced increase critical particle density friction coefficient increase. Nevertheless, moblised zone practically independent both buried

Language: Английский

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