We consider experimentally and computationally the phenomenon of the reverse Janssen effect, involving the counterintuitive finding that the force on the base of a column containing granular particles may be larger than the weight of the granular material itself. This finding is in contrast to the c…

[Phys. Rev. E 110, 064901] Published Wed Dec 11, 2024

The mean square displacement (MSD) of intruders (tracer particles) immersed in a multicomponent granular mixture made up of smooth inelastic hard spheres in a homogeneous cooling state is explicitly computed. The multicomponent granular mixture consists of $s$ species with different masses, diameters,…

[Phys. Rev. E 110, 064902] Published Wed Dec 11, 2024

Granular fluids, as defined by a collection of moving solid particles, is a paradigm of a dissipative system out of equilibrium. Inelastic collisions between particles is the source of dissipation, and is the origin of a transition from a gas to a liquidlike state. This transition can be triggered b…

[Phys. Rev. E 110, 054901] Published Fri Nov 22, 2024

Soot aerosols emitted during combustion can affect climate by scattering and absorbing the sunlight. Individual soot particles are fractal aggregates composed of elemental carbon. In the atmosphere, these aggregates acquire coatings by condensation and coagulation, resulting in significant compactio…

[Phys. Rev. E 110, 054902] Published Fri Nov 22, 2024

Granular materials in nature are nearly always nonspherical, but particle shape effects in granular flow remain largely elusive. This study uses discrete element method simulations to investigate how elongated particle shapes affect the mobility of dense granular flows down a rough incline. For a ra…

[Phys. Rev. E 110, 044902] Published Wed Oct 23, 2024

We conducted avalanching experiments with an external magnetic field and granular samples of different grain sizes (3.18 mm, 6.35 mm, and 8.73 mm) and different materials (low-carbon steel, alloy steel, stainless steel, and brass). The magnetic field was varied to control the magnetic Bond number (t…

[Phys. Rev. E 110, 044901] Published Fri Oct 18, 2024

We study the flow of grains under vibration passing through a small aperture in two dimensions using discrete element method simulations. Such systems are prone to clogging and strategies to ease the flow are desirable in multiple applications. We show that the addition of low-friction particles to …

[Phys. Rev. E 110, 034902] Published Mon Sep 30, 2024

We study the rheology of bidisperse non-Brownian suspensions using particle-based simulation, mapping the viscosity as a function of the size ratio of the species, their relative abundance, and the overall solid content. The variation of the viscosity with applied stress exhibits shear-thickening ph…

[Phys. Rev. E 110, 034901] Published Fri Sep 20, 2024

This work investigates the interaction between gas channels in a vertical Hele-Shaw cell when air is injected simultaneously from two points at a constant flow rate. Unlike single-injection experiments, this dual-point system induces the formation of numerous bubbles, thereby intensifying the intera…

[Phys. Rev. E 110, 024901] Published Mon Aug 12, 2024

With magnetic resonance imaging experiments, we study packings of granular spherocylinders with merely 2% asphericity. Evident structural anisotropies across all length scales are identified. Most interestingly, the global nematic order decreases with increasing packing fraction, while the local con…

[Phys. Rev. E 110, 014903] Published Tue Jul 30, 2024

The jamming transition is an important feature of granular materials, with prior work showing an excess of low-frequency modes in the granular analog to the density of states, the granular density of modes. In this work, we present an experimental method for acoustically measuring the granular densi…

[Phys. Rev. E 110, 014902] Published Wed Jul 24, 2024

We investigate experimentally the impact process of sand particles onto a cohesive granular packing made of similar particles. We use a sand-oil mixture with varying liquid content to tune the cohesive strength of the packing. The outcome of the impact is analyzed in terms of the production of eject…

[Phys. Rev. E 110, 014901] Published Mon Jul 22, 2024

The drag force acting on an intruder colliding with granular media is typically influenced by the impact velocity and the penetrating depth. In this paper, the investigation was extended to the dry and immersed scenarios through coupled simulations at different penetrating velocities. The drag force…

[Phys. Rev. E 109, 064908] Published Mon Jun 24, 2024

Laboratory granular landslides are smaller-scale, simplified, yet well-controlled versions of larger and often tragic natural landslides. Using systematic experiments and scaling analysis, we quantify the influence of grain size, fall height, and landslide volume on runout distance. We also determin…

[Phys. Rev. E 109, 064907] Published Thu Jun 20, 2024

In this work, we performed experiments regarding the outflow of spheres and two different types of rice-shaped particles in a quasi-two-dimensional monolayer silo with a flat bottom. We investigate the velocity and solid fraction profiles at the orifice and test whether the profiles for nonspherical…

[Phys. Rev. E 109, 064906] Published Tue Jun 18, 2024

Circles of a single size can pack together densely in a hexagonal lattice, but adding in size variety disrupts the order of those packings. We conduct simulations which generate dense random packings of circles with specified size distributions and measure the area fraction in each case. While the s…

[Phys. Rev. E 109, 064905] Published Mon Jun 17, 2024

We study the jamming transition in a model of elastic particles under shear at zero temperature, with a focus on the relaxation time ${\tau }_1$. This relaxation time is from two-step simulations where the first step is the ordinary shearing simulation and the second step is the relaxation of the energy afte…

[Phys. Rev. E 109, 064904] Published Thu Jun 06, 2024

The interaction between two large spherical particles, called intruders, in a dry granular flow down an incline is brought to light and studied experimentally and numerically. Several parameters are varied, namely, the size ratio between the intruders and the small flowing particles, the thickness o…

[Phys. Rev. E 109, 064903] Published Tue Jun 04, 2024

Non-Newtonian transport properties of a dilute gas of inelastic hard spheres immersed in a molecular gas are determined. We assume that the granular gas is sufficiently rarefied, and hence the state of the molecular gas is not disturbed by the presence of the solid particles. In this situation, one …

[Phys. Rev. E 109, 064901] Published Mon Jun 03, 2024

The dense active matter exhibits characteristics reminiscent of traditional glassy phenomena, yet the role of rotational inertia in glass dynamics remains elusive. In this study, we investigate the glass dynamics of chiral active particles influenced by rotational inertia. Rotational inertia endows …

[Phys. Rev. E 109, 064902] Published Mon Jun 03, 2024

Impact crater experiments in granular media traditionally involve loosely packed sand targets. However, this study investigates granular impact craters on both loosely and more tightly packed sand targets. We report experiments that consistently adhere to power-law scaling laws for diameter as a fun…

[Phys. Rev. E 109, 054907] Published Tue May 28, 2024

There have been some interesting recent advances in understanding the notion of mechanical disorder in structural glasses and the statistical mechanics of these systems' low-energy excitations. Here we contribute to these advances by studying a minimal model for structural glasses' elasticity in whi…

[Phys. Rev. E 109, 054906] Published Fri May 24, 2024

The mean-field theory (MFT) of simple structural glasses, which is exact in the limit of infinite spatial dimensions, $d\to \infty$, offers theoretical insight as well as quantitative predictions about certain features of $d=3$ systems. In order to more systematically relate the behavior of physical systems to …

[Phys. Rev. E 109, 054905] Published Thu May 23, 2024

The mechanical behavior of granular materials results from interparticle interactions, which are predominantly frictional. With the presence of even very small amounts of cohesion this frictional interparticle behavior significantly changes. In this study, we introduce trace amounts of cohesive bind…

[Phys. Rev. E 109, 054903] Published Tue May 21, 2024

Many fibrous materials are modeled as elastic networks featuring a substantial separation between the stiffness scales that characterize different microscopic deformation modes of the network's constituents. This scale separation has been shown to give rise to emergent complexity in these systems' l…

[Phys. Rev. E 109, 054904] Published Tue May 21, 2024

We investigate experimentally the influence of rotation on the penetration depth of a spherical projectile impacting a granular medium. We show that a rotational motion significantly increases the penetration depth achieved. Moreover, we model our experimental results by modifying the frictional ter…

[Phys. Rev. E 109, 054902] Published Mon May 13, 2024

We report on the construction of a granular network of particles to study the formation, evolution, and statistical properties of clusters of particles developing at the vicinity of a liquid-solid-like phase transition within a vertically vibrated quasi-two-dimensional granular system. Using the dat…

[Phys. Rev. E 109, 054901] Published Wed May 01, 2024

Using a discrete element method, we investigate the phenomenon of geometric cohesion in granular systems composed of star-shaped particles with 3 to 13 arms. This was done by analyzing the stability of columns built with these particles and by studying the microstructure of these columns in terms of…

[Phys. Rev. E 109, 044908] Published Tue Apr 30, 2024

We introduce an approach to particle breakage, wherein the particle is modeled as an aggregate of polyhedral cells with their common surfaces governed by the Griffith criterion of fracture. This model is implemented within a discrete element code to simulate and analyze the breakage behavior of a si…

[Phys. Rev. E 109, 044907] Published Mon Apr 29, 2024

The hydraulic conveying of glass beads is studied in a horizontal tube. At low flow rates, plugs can be observed moving across the tube, whereas pseudoplugs can be seen at higher flow rates. A statistical analysis of the plugs' and pseudoplugs' velocities and the plugs' lengths observed is conducted…

[Phys. Rev. E 109, 044906] Published Wed Apr 24, 2024

We examine an assembly of repulsive disks interacting with a random obstacle array under a periodic drive and find a transition from reversible to irreversible dynamics as a function of drive amplitude or disk density. At low densities and drives, the system rapidly forms a reversible state where th…

[Phys. Rev. E 109, 044905] Published Fri Apr 19, 2024

We present a universal characterization of stress correlations in athermal systems, across crystalline to amorphous packings. Via numerical analysis of static configurations of particles interacting through harmonic as well as Lennard-Jones potentials, for a variety of preparation protocols and rang…

[Phys. Rev. E 109, 044903] Published Thu Apr 18, 2024

In this paper, we study the granular equation of state (EOS) for computer-generated three-dimensional mechanically stable packings of frictional monodisperse particles over a wide range of densities (packing fractions), $\phi =0.56$–0.72. As a statistical physics framework, we utilize the statistical ense…

[Phys. Rev. E 109, 044904] Published Thu Apr 18, 2024

Heat transfer across a granular flow is comprised of two resistances in series : near the wall and within the bulk particle bed, neither of which is well understood due to the lack of experimental probes to separate their respective contribution. Here, we use a frequency modulated photothermal techn…

[Phys. Rev. E 109, L042902] Published Mon Apr 15, 2024

In recent work it was shown that elasticity theory can break down in amorphous solids subjected to nonuniform static loads. The elastic fields are screened by geometric dipoles; these stem from gradients of the quadrupole field associated with plastic responses. Here we study the dynamical responses…

[Phys. Rev. E 109, 044902] Published Thu Apr 04, 2024

Acoustic trapping uses forces exerted by sound waves to transport small objects along specified trajectories in three dimensions. The structure of the time-averaged acoustic force landscape acting on an object is determined by the amplitude and phase profiles of the sound's pressure wave. These prof…

[Phys. Rev. E 109, 044901] Published Tue Apr 02, 2024

Oscillatory-driven amorphous materials forget their initial configuration and converge to limit cycles. Here we investigate this memory loss under a nonquasistatic drive in a minimal model system, with quenched disorder and memory encoded in a spatial pattern, where oscillating protocols are formall…

[Phys. Rev. E 109, L042901] Published Mon Apr 01, 2024

The energy transfer between bouncing particles and rigid boundaries during impacts is crucially influenced not only by restitution coefficients of the material but also by particle shapes. This is particularly important when such particles are mechanically agitated with vibrating plates. Inertial me…

[Phys. Rev. E 109, 034903] Published Thu Mar 21, 2024

From colloid suspension to particle aggregation in protoplanetary formation, electrostatic attraction and repulsion between particles is a key mechanism behind the aggregation and clustering of particles. Although most studies have focused on canonical spherical particles, it remains unclear how non…

[Phys. Rev. E 109, 034902] Published Tue Mar 19, 2024

We investigate, using a recently developed model of liquid state theory describing the rheology of dense granular flows, how a yield stress appears in granular matter at the yielding transition. Our model allows us to predict an analytical equation of the corresponding dynamical yield surface, which…

[Phys. Rev. E 109, 034901] Published Mon Mar 04, 2024

We perform a numerical simulation of compression of a highly porous dust aggregate of monodisperse spheres. We find that the average interparticle normal force within the aggregate is inversely proportional to both the filling factor and the average coordination number and we also derive this relati…

[Phys. Rev. E 109, 024904] Published Tue Feb 27, 2024

We investigate diffusion in polydisperse granular media. We derive the mean-squared displacement of granular particles in a polydisperse granular gas in a homogeneous cooling state, containing an arbitrary amount of species of different sizes and masses. We investigate both models of constant and ti…

[Phys. Rev. E 109, 024903] Published Thu Feb 15, 2024

We study the transition from cohesive to noncohesive states of cemented granular materials (synthetic rocks) under oedometric loading, combining simultaneous measurements of ultrasound velocity and acoustic emission (AE: microseosmicity). Our samples are agglomerates made of glass beads bonded with …

[Phys. Rev. E 109, 024902] Published Mon Feb 12, 2024

Superellipse sector particles (SeSPs) are segments of superelliptical curves that form a tunable set of hard-particle shapes for granular and colloidal systems. SeSPs allow for continuous parametrization of corner sharpness, aspect ratio, and particle curvature; rods, circles, rectangles, and staple…

[Phys. Rev. E 109, 024901] Published Fri Feb 09, 2024

We investigate the occurrence of spontaneous convection in a coaxial cylinder highly filled with monodisperse spheres. To analyze the flow field noninvasively, initial pulses consisting of colored particles are placed at equal intervals. By analyzing the spatiotemporal distribution of these pulses, …

[Phys. Rev. E 109, L022901] Published Fri Feb 02, 2024

Using the three-dimensional discrete element method, we numerically investigate the collapse dynamics and deposition morphology of low-viscocohesive granular columns on a rough-horizontal plane by systematically varying a broad range of values of the initial column aspect ratio, cohesive stress, and…

[Phys. Rev. E 109, 014904] Published Wed Jan 24, 2024

We experimentally investigate the dynamics of a sphere rolling up a granular slope. During the rolling-up motion, the sphere experiences slipping and penetration (groove formation) on the surface of the granular layer. The former relates to the stuck motion of the rolling sphere, and the latter caus…

[Phys. Rev. E 109, 014903] Published Fri Jan 12, 2024

A significant amount of attention was dedicated in recent years to the phenomenon of jamming of athermal amorphous solids by increasing the volume fraction of the microscopic constituents. At a critical value of the volume fraction, pressure shoots up from zero to finite values with a host of critic…

[Phys. Rev. E 109, 014902] Published Mon Jan 08, 2024

A basic problem in the science of realistic granular matter is the plethora of heuristic models of the stress field in the absence of a first-principles theory. Such a theory is formulated here, based on the idea that static granular assemblies can be regarded as two-phase composites. A thought expe…

[Phys. Rev. E 109, 014901] Published Thu Jan 04, 2024

We present measurements of the vertical stress profile $\sigma$ on the base of flat-bottomed cylindrical silos discharged through an orifice centered on its base. An overweight forces the material on top of the free surface. The mean bottom pressure $\sigma (z,D,W)$, with $z$ the height of the granular column, $D$ the…

[Phys. Rev. E 109, L012901] Published Thu Jan 04, 2024

When objects are forced to flow through constrictions their transport can be frustrated temporarily or permanently due to the formation of arches in the region of the bottleneck. While such systems have been intensively studied in the case of solid particles in a gas phase being forced by gravitatio…

[Phys. Rev. E 108, 064905] Published Mon Dec 18, 2023

The compression of brittle porous media can lead to the propagation of compaction bands. Although such localization phenomena have been observed in different geometries, including cuboidal and axisymmetric uniaxial compression, the role of boundary geometry on compaction features has yet to be explo…

[Phys. Rev. E 108, 064906] Published Mon Dec 18, 2023

The triggering of avalanches is investigated using discrete element simulations for a process of random extraction of spheres. A monolayer, formed by identical spheres in a hexagonal configuration, is placed on a tilted plane surrounded by a small fence that sustains the spheres, mimicking the dispo…

[Phys. Rev. E 108, 064904] Published Thu Dec 14, 2023

Acoustic traps use forces exerted by sound waves to confine and transport small objects. The dynamics of an object moving in the force landscape of an acoustic trap can be significantly influenced by the inertia of the surrounding fluid medium. These inertial effects can be observed by setting a tra…

[Phys. Rev. E 108, 064903] Published Tue Dec 05, 2023

Granular fluidity has been central to the development of nonlocal constitutive equations, which are necessary for characterizing nonlocal effects observed in experimental granular flow data. However, validation of these equations has been largely computational due to challenges in laboratory experim…

[Phys. Rev. E 108, 064902] Published Mon Dec 04, 2023

We investigate the force of flowing granular material on an obstacle. A sphere suspended in a discharging silo experiences both the weight of the overlaying layers and drag of the surrounding moving grains. In experiments with frictional hard glass beads, the force on the obstacle was practically fl…

[Phys. Rev. E 108, L062901] Published Mon Dec 04, 2023

Jamming is an emergent phenomenon wherein the local stability of individual particles percolates to form a globally rigid structure. However, the onset of rigidity does not imply that every particle becomes rigid, and indeed some remain locally unstable. These particles, if they become unmoored from…

[Phys. Rev. E 108, 064901] Published Fri Dec 01, 2023

It is well known that energy dissipation and finite size can deeply affect the dynamics of granular matter, often making usual hydrodynamic approaches problematic. Here we report on the experimental investigation of a small model system, made of ten beads constrained into a 1D geometry by a narrow v…

[Phys. Rev. E 108, 054906] Published Thu Nov 30, 2023

We are exploring in experiments the aggregation process in a shaken granular mixture of glass and magnetized steel beads, filled in a horizontal vessel, after the shaking amplitude is suddenly decreased. Then the magnetized beads form a transient network that coarsens in time into compact clusters, …

[Phys. Rev. E 108, 054905] Published Mon Nov 27, 2023

Numerical simulations reveal that an impact crater’s shape can depend on the impactor’s spin and its degree of cohesion.

[Phys. Rev. E 108, 054904] Published Wed Nov 22, 2023

In quasi-two-dimensional experiments with photoelastic particles confined to an annular region, an intruder constrained to move in a circular path halfway between the annular walls experiences stick-slip dynamics. We discuss the response of the granular medium to the driven intruder, focusing on the…

[Phys. Rev. E 108, 054903] Published Wed Nov 15, 2023

Granular flows occur in various contexts, including laboratory experiments, industrial processes, and natural geophysical flows. To investigate their dynamics, different kinds of physically based models have been developed. These models can be characterized by the length scale at which dynamic proce…

[Phys. Rev. E 108, 054902] Published Mon Nov 06, 2023

By means of two-dimensional numerical simulations based on contact dynamics, we present a systematic analysis of the joint effects of grain shape (i.e., grain elongation) and system size on silo discharge for increasing orifice sizes $D$. Grains are rounded-cap rectangles whose aspect ratio are varied…

[Phys. Rev. E 108, 054901] Published Wed Nov 01, 2023

The flow of elliptical particles out of a two-dimensional silo when extracted with a conveyor belt is analyzed experimentally. The conveyor belt—placed directly below the silo outlet—reduces the flow rate, increases the size of the stagnant zone, and it has a very strong influence on the relative ve…

[Phys. Rev. E 108, 044902] Published Tue Oct 24, 2023

Very soft grain assemblies have unique shape-changing capabilities that allow them to be compressed far beyond the rigid jammed state by filling void spaces more effectively. However, accurately following the formation of these systems by monitoring the creation of new contacts, monitoring the chang…

[Phys. Rev. E 108, 044901] Published Mon Oct 23, 2023

Static structure factors are computed for large-scale, mechanically stable, jammed packings of frictionless spheres (three dimensions) and disks (two dimensions) with broad, power-law size dispersity characterized by the exponent $-\beta$. The static structure factor exhibits diverging power-law behavior …

[Phys. Rev. E 108, L042902] Published Fri Oct 20, 2023

When amorphous solids are subjected to simple or pure strain, they exhibit elastic increase in stress, punctuated by plastic events that become denser (in strain) upon increasing the system size. It is customary to assume in theoretical models that the stress released in each plastic event is redist…

[Phys. Rev. E 108, L042901] Published Wed Oct 04, 2023

Particle-embedded materials consist of a dispersed phase of particles in a sticking matrix. We used a bond-based peridynamics method to investigate their elastic properties, rupture, and probability of failure. We performed an extensive two-dimensional parametric study where particles are disk-shape…

[Phys. Rev. E 108, 034903] Published Thu Sep 21, 2023

A bonded particle model is used to explore how variations in the material properties of brittle, isotropic solids affect critical behavior in fragmentation. To control material properties, a model is proposed which includes breakable two- and three-body particle interactions to calibrate elastic mod…

[Phys. Rev. E 108, 034902] Published Tue Sep 12, 2023

Jammed packings of granular materials display complex mechanical response. For example, the ensemble-averaged shear modulus $\langle G\rangle$ increases as a power law in pressure $p$ for static packings of soft spherical particles that can rearrange during compression. We seek to design granular materials with shea…

[Phys. Rev. E 108, 034901] Published Wed Sep 06, 2023

We do extensive simulations of a simple model of shear-driven jamming in two dimensions to determine and analyze the velocity distribution at different densities $\varphi$ around the jamming density ${\varphi }_J$ and at different low shear strain rates, $\dot{\gamma }$. We then find that the velocity distribution is made up of two…

[Phys. Rev. E 108, 024904] Published Wed Aug 23, 2023

The Enskog kinetic theory is applied to compute the mean square displacement of impurities or intruders (modeled as smooth inelastic hard spheres) immersed in a granular gas of smooth inelastic hard spheres (grains). Both species (intruders and grains) are surrounded by an interstitial molecular gas…

[Phys. Rev. E 108, 024903] Published Mon Aug 21, 2023

The Mpemba effect refers to the counterintuitive effect where a system which is initially further from the final steady state equilibrates faster than an identical system that is initially closer. The closeness to the final state is defined in terms of a distance measure. For driven granular systems…

[Phys. Rev. E 108, 024902] Published Mon Aug 14, 2023

We report an instability of a slider slowly dragged at the surface of a granular bed in a quasistatic regime. The boat-shaped slider sits on the granular medium under its own weight and is free to translate vertically and to rotate around the pitch axis while a constant horizontal speed is imposed. …

[Phys. Rev. E 108, 024901] Published Wed Aug 09, 2023

Pressurized fluid injection into underground rocks occurs in applications like carbon sequestration, hydraulic fracturing, and wastewater disposal and may lead to human-induced earthquakes and surface uplift. The fluid injection raises the pore pressure within the porous rocks, while deforming them,…

[Phys. Rev. E 108, L022901] Published Fri Aug 04, 2023

Experiments show that an optimal distance between points of contact helps insects and other multilegged creatures avoid slipping down a steep granular slope.

[Phys. Rev. E 108, 014903] Published Tue Jul 25, 2023

The importance of roughness in the modeling of granular gases has been increasingly considered in recent years. In this paper, a freely evolving homogeneous granular gas of inelastic and rough hard disks or spheres is studied under the assumptions of the Boltzmann kinetic equation. The homogeneous c…

[Phys. Rev. E 108, 014902] Published Thu Jul 13, 2023

A new method based on satellite data and network models can identify hillsides that may be at risk of catastrophic landslides.

[Phys. Rev. E 108, 014901] Published Thu Jul 06, 2023

Rheology of macroscopic particle-laden interfaces, called “granular rafts,” has been experimentally studied in the simple shear configuration. The shear-stress relation obtained from a classical rheometer exhibits the same behavior as a Bingham fluid, and the viscosity diverges with the surface frac…

[Phys. Rev. E 107, 064901] Published Thu Jun 29, 2023

Packings of beads confined in slowly tilted containers with a top free surface are commonly used in laboratory experiments to model natural grain avalanches and better understand and predict critical events from optical measurements of the surface activity. To that aim, after reproducible packing pr…

[Phys. Rev. E 107, 054906] Published Fri May 26, 2023

We analyze the cluster formation in a nonergodic stochastic system as a result of counterflow, with the aid of an exactly solvable model. To illustrate the clustering, a two species asymmetric simple exclusion process with impurities on a periodic lattice is considered, where the impurity can activa…

[Phys. Rev. E 107, 054905] Published Mon May 22, 2023

Strain-controlled isotropic compression gives rise to jammed packings of repulsive, frictionless disks with either positive or negative global shear moduli. We carry out computational studies to understand the contributions of the negative shear moduli to the mechanical response of jammed disk packi…

[Phys. Rev. E 107, 054903] Published Fri May 19, 2023

We study two-dimensional random sequential adsorption (RSA) of flat polygons and rounded squares aligned in parallel to find a transition in the asymptotic behavior of the kinetics of packing growth. Differences in the kinetics for RSA of disks and parallel squares were confirmed in previous analyti…

[Phys. Rev. E 107, 054904] Published Fri May 19, 2023

Granular materials are used in several fields and in a wide variety of processes. An important feature of these materials is the diversity of grain sizes, commonly referred to as polydispersity. When granular materials are sheared, they exhibit a predominant small elastic range. Then, the material y…

[Phys. Rev. E 107, L052901] Published Fri May 12, 2023

We consider a sheared granular system experiencing intermittent dynamics of stick-slip type via discrete element simulations. The considered setup consists of a two-dimensional system of soft frictional particles sandwiched between solid walls, one of which is exposed to a shearing force. The slip e…

[Phys. Rev. E 107, 054901] Published Wed May 10, 2023

Using the Jacobian matrix, we obtain a theoretical expression of rigidity and the density of states of two-dimensional amorphous solids consisting of frictional grains in the linear response to an infinitesimal strain, in which we ignore the dynamical friction caused by the slip processes of contact…

[Phys. Rev. E 107, 054902] Published Wed May 10, 2023

The contact stiffness of an aluminum bead confined between two slabs diminishes upon mechanical conditioning, and then recovers as $log\left(t\right)$ after the conditioning ceases. Here that structure is evaluated for its response to transient heating and cooling, with and without accompanying conditioning vibr…

[Phys. Rev. E 107, 044902] Published Mon Apr 24, 2023

From small seeds falling from trees to asteroids colliding with planets and moons, the impact of projectiles onto granular targets occurs in nature at different scales. In this paper, we investigate open questions in the mechanics of granular cratering, in particular, the forces acting on the projec…

[Phys. Rev. E 107, 044901] Published Fri Apr 21, 2023

Dirt cones are meter-scale structures encountered at the surface of glaciers, which consist of ice cones covered by a thin layer of ashes, sand, or gravel, and which form naturally from an initial patch of debris. In this article, we report field observations of cone formation in the French Alps, la…

[Phys. Rev. E 107, 034905] Published Tue Mar 28, 2023

The stress-strain curve of two-dimensional frictional dispersed grains interacting with a harmonic potential without considering the dynamical slip under a finite strain is determined by using eigenvalue analysis of the Hessian matrix. After the configuration of grains is obtained, the stress-strain…

[Phys. Rev. E 107, 034904] Published Tue Mar 21, 2023

We present an experimental study of the dynamics of a set of magnets within a fluid in which a remote torque applied by a vertical oscillating magnetic field transfers angular momentum to individual magnets. This system differs from previous experimental studies of granular gas where the energy is i…

[Phys. Rev. E 107, 034903] Published Mon Mar 20, 2023

We study plastic strain during individual avalanches in overdamped particle-scale molecular dynamics (MD) and mesoscale elastoplastic models (EPM) for amorphous solids sheared in the athermal quasistatic limit. We show that the spatial correlations in plastic activity exhibit a short length scale th…

[Phys. Rev. E 107, 034902] Published Wed Mar 15, 2023

Experiments have shown that charge distributions of granular materials are non-Gaussian, with broad tails that indicate many particles with high charge. This observation has consequences for the behavior of granular materials in many settings, and may bear relevance to the underlying charge transfer…

[Phys. Rev. E 107, 034901] Published Wed Mar 08, 2023

It has been shown that a nonvibrating magnetic granular system, when fed by an alternating magnetic field, behaves with most of the distinctive physical features of active matter systems. In this work, we focus on the simplest granular system composed of a single magnetized spherical particle alloca…

[Phys. Rev. E 107, 024902] Published Fri Feb 17, 2023

Understanding the clogging of mixtures of soft and rigid particles flowing through hoppers becomes important as soft particle usage increases in consumer products. We investigate this clogging under varying particle size and rigid fraction by quantifying various properties of arches formed in the ne…

[Phys. Rev. E 107, 024901] Published Wed Feb 01, 2023

We study the percolation of a fine spherical particle under gravity in static randomly packed large-particle beds with different packing densities $\varphi$ and large to fine particle size ratios $R$ ranging from 4 to 7.5 using discrete element method simulations. The particle size ratio at the geometrical tr…

[Phys. Rev. E 107, 014903] Published Mon Jan 30, 2023

In the case of media comprised of impermeable particles, fluid flows through voids around impenetrable grains. For sufficiently low concentrations of the latter, spaces around grains join to allow transport on macroscopic scales, whereas greater impenetrable inclusion densities disrupt void networks…

[Phys. Rev. E 107, 014902] Published Fri Jan 27, 2023

Using a simplified model for a non-Brownian suspension, we numerically study the response of athermal, overdamped, frictionless disks in two dimensions to isotropic and uniaxial compression, as well as to pure and simple shearing, all at finite constant strain rates $\dot{\epsilon }$. We show that isotropic and un…

[Phys. Rev. E 107, 014901] Published Thu Jan 12, 2023

We derive exact probability distributions for the strain ($\epsilon$) at which the first stress drop event occurs in uniformly strained disordered crystals, with quenched disorder introduced through polydispersity in particle sizes. We characterize these first stress drop events numerically as well as theore…

[Phys. Rev. E 106, 064901] Published Thu Dec 22, 2022

The Enskog kinetic theory of multicomponent granular suspensions employed previously [Gómez González, Khalil, and Garzó, Phys. Rev. E 101, 012904 (2020)] is considered further to determine the four transport coefficients associated with the heat flux. These transport coefficients are obtained by sol…

[Phys. Rev. E 106, 064902] Published Thu Dec 22, 2022