arXiv subjects

Huzaif Rahim

Publications and source records attributed to Huzaif Rahim.

4 recordsLinked to original sources

arXiv2026

Dilatancy-induced surface deformation in dense cohesive granular media

When granular materials with interstitial liquid bridges are sheared in a split-bottom cell, a localized shear band develops, accompanied by a surface elevation. Cohesion, governed by the surface tension of the interstitial liquid, enhances dilatancy in dense cohesive packings, leading to expansion within the shear band and the emergence of a surface elevation. Surface deformation is observed not only in cohesive systems with high particle density and large liquid surface tension, but also in those with lower values of these parameters. The equivalent Bond number arises as a key control parameter for the surface deformation, shaping both the evolution of the surface profile and the packing density. At higher shear rates, inertial effects dominate dilatancy, resulting in less pronounced surface deformation.

cond-mat.soft↗

arXiv2025

Shear-induced pressure anisotropy in granular materials of nonspherical particles

When a granular material composed of elongated grains is sheared in a split-bottom shear cell, a pressure difference develops within the material. This pressure difference depends on the interparticle friction ($\mu$), which affects shear localization and particle alignment. For large $\mu$, alignment is confined to a narrow shear band, leading to localized increases in packing density and pressure. For small $\mu$, particles align over a wider region, leading to a nearly uniform packing density and pressure throughout the material. In contrast, spherical particles, regardless of $\mu$, maintain a uniform packing density and pressure throughout the material. We observe a phenomenological similarity to the Weissenberg effect in non-Newtonian fluids, where normal stress differences induce radial pressure gradients, unlike the uniform pressure in Newtonian fluids.

cond-mat.soft↗

arXiv2025

Impact of friction and grain shape on the morphology of sheared granular media

The interplay between dilatancy and particle alignment in sheared granular materials composed of non-spherical particles leads to morphological inhomogeneity. Dilatancy, driven by interparticle friction, causes the packing to expand, while particle alignment tends to densify it. We examine the influence of friction, particle aspect ratio, and initial packing conditions on the steady-state particle alignment and packing density. Unlike spherical particles, non-spherical particles with higher AR exhibit either dilatancy or compaction under shear, leading to spontaneous heaping or depression formation. We analyzed the evolution of packing density to identify whether dilatancy or compression prevails within the shear band.

cond-mat.soft↗

arXiv2024

Alignment-induced depression and shear thinning of anisotropic granular media

When granular materials of shape-anisotropic grains are sheared in a split-bottom shear cell, a localized shear band is formed with a depression at its center. This effect is closely related to the alignment of the particles with aspect ratio (AR), which, in turn, influences the local packing density, the stress distribution, and the system's overall bulk rheology. Particles with large AR tend to align with the shear direction, which increases the packing density in the shear band and affects rheological properties like stress, macroscopic friction coefficient, and effective viscosity. A scaling law correlates particle AR to macroscopic friction and effective viscosity, revealing shear-thinning behavior in bulk and near the surface.

cond-mat.soft↗