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 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 , with the height of the granular column, 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 . 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 . 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 increases as a power law in pressure 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 around the jamming density and at different low shear strain rates, . 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 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 and large to fine particle size ratios 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 . We show that isotropic and un…
[Phys. Rev. E 107, 014901] Published Thu Jan 12, 2023
]]>We derive exact probability distributions for the strain () 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
]]>We experimentally investigate the velocity distributions of quasi-two-dimensional granular materials uniformly heated by an electromagnetic vibrator, where the translational velocity and the rotation of a single particle are Gaussian and independent. We observe the non-Gaussian distributions of part…
[Phys. Rev. E 106, L052903] Published Wed Nov 30, 2022
]]>We derive exact results for the fluctuations in energy produced by microscopic disorder in near-crystalline athermal systems. Our formalism captures the heterogeneity in the elastic energy of polydisperse soft disks in energy-minimized configurations. We use this to predict the distribution of inter…
[Phys. Rev. E 106, L052902] Published Mon Nov 28, 2022
]]>We present three-dimensional discrete element method simulations of bidisperse granular packings to investigate their jamming densities and dimensionless bulk moduli as functions of the size ratio and the concentration of small particles . We determine the partial and total bulk moduli for …
[Phys. Rev. E 106, 054903] Published Wed Nov 16, 2022
]]>We consider the penetration dynamics of a vertical cylinder into a dry granular medium subjected to successive impacts. The depth of the impactor below the free surface first evolves linearly with the impact number and then follows a power-law evolution . The depth reached by the cylinde…
[Phys. Rev. E 106, 054904] Published Wed Nov 16, 2022
]]>We report experimental evidence of a Gardner-like crossover from variable to persistent force contacts in a two-dimensional bidisperse granular crystal by analyzing the variability of both particle positions and force networks formed under uniaxial compression. Starting from densities just above the…
[Phys. Rev. E 106, 054901] Published Tue Nov 15, 2022
]]>Particle image velocimetry has been applied to measure particle velocities on the free surface of a bed of particles within a rotating cylinder during avalanching. The particle velocities were used to examine the validity of existing avalanche models and to propose an alternative model. The movement…
[Phys. Rev. E 106, 054902] Published Tue Nov 15, 2022
]]>Studies of granular materials, both theoretical and experimental, are often restricted to convex grain shapes. We demonstrate that a nonconvex grain shape can lead to a qualitatively novel macroscopic dynamics. Spatial crosses (hexapods) are continuously sheared in a split-bottom container. Thereby,…
[Phys. Rev. E 106, L052901] Published Thu Nov 03, 2022
]]>A correlation between density maximization and size segregation for packings of polydisperse particles in geometric confinement has been discovered, through the derivation of a general solution for the densest-packed zigzag arrangements of polydisperse particles. This solution is a size-graded struc…
[Phys. Rev. E 106, L042902] Published Tue Oct 25, 2022
]]>In computational models of particle packings with periodic boundary conditions, it is assumed that the packing is attached to exact copies of itself in all possible directions. The periodicity of the boundary then requires that all of the particles' images move together. An infinitely repeated struc…
[Phys. Rev. E 106, 044901] Published Tue Oct 18, 2022
]]>The rheological response of oriented axisymmetric grains has additional degrees of complexity associated with their microstructure orientation. These additional kinematic degrees of freedom that give rise to complex transient macroscale rheological responses are not well understood. In this Letter, …
[Phys. Rev. E 106, L042901] Published Mon Oct 03, 2022
]]>In this paper, the prototypical process of the normal impact of dense agglomerates is investigated using the discrete element method–boundary element method coupled simulations. The agglomerate consists of 50 charged particles with the surface energy equal to . The particles are assumed to be…
[Phys. Rev. E 106, 034905] Published Tue Sep 27, 2022
]]>Applying constant tensile stress to a piece of amorphous solid results in a slow extension, followed by an eventual rapid mechanical collapse. This “creep” process is of paramount engineering concern, and as such was the subject of study in a variety of materials, for more than a century. Predictive…
[Phys. Rev. E 106, 034906] Published Tue Sep 27, 2022
]]>The discharge of elongated particles from a silo with rotating bottom is investigated numerically. The introduction of a slight transverse shear reduces the flow rate by up to 70% compared with stationary bottom, but the flow rate shows a modest increase by further increasing the external shear. F…
[Phys. Rev. E 106, 034904] Published Wed Sep 21, 2022
]]>In this Letter, we discuss how flow inhomogeneity affects the self-diffusion behavior in granular flows. Whereas self-diffusion scalings have been well characterized in the past for homogeneous shearing, the effect of shear localization and nonlocality of the flow has not been studied. We, therefore…
[Phys. Rev. E 106, L032901] Published Mon Sep 19, 2022
]]>We experimentally study the unjamming dynamics of strongly compressed particle rafts confined between two fixed walls and two movable barriers. The back barrier is made of an elastic band, whose deflection indicates the local stress. The front barrier is pierced by a gate, whose opening triggers loc…
[Phys. Rev. E 106, 034903] Published Fri Sep 16, 2022
]]>The role of fixed degrees of freedom in soft or granular matter systems has broad applicability and theoretical interest. Here we address questions of the geometrical role that a scaffolding of fixed particles plays in tuning the threshold volume fraction and force network in the vicinity of jamming…
[Phys. Rev. E 106, 034902] Published Tue Sep 06, 2022
]]>Due to significant computational expense, discrete element method simulations of jammed packings of size-dispersed spheres with size ratios greater than 1:10 have remained elusive, limiting the correspondence between simulations and real-world granular materials with large size dispersity. Invoking …
[Phys. Rev. E 106, 034901] Published Fri Sep 02, 2022
]]>Several mean-field theories predict that the Hessian matrix of amorphous solids converges the Wishart matrix in the limit of the large spatial dimensions . Motivated by these results, we calculate here the density of states of random packing of harmonic spheres by mapping the Hessian of the origi…
[Phys. Rev. E 106, 024904] Published Thu Aug 25, 2022
]]>A spatial distribution is hyperuniform if it has local density fluctuations that vanish in the limit of long length scales. Hyperuniformity is a well known property of both crystals and quasicrystals. Of recent interest, however, is disordered hyperuniformity: the presence of hyperuniform scaling wi…
[Phys. Rev. E 106, 024903] Published Thu Aug 18, 2022
]]>Flow of size-bidisperse particle mixtures in a spherical tumbler rotating alternately about two perpendicular axes produces segregation patterns that track the location of nonmixing islands predicted by a dynamical systems approach. To better understand the paradoxical accumulation of large particle…
[Phys. Rev. E 106, 024902] Published Thu Aug 11, 2022
]]>Different regimes are usually observed for fluid migration through an immersed granular layer. In this work, we report a puzzling behavior when injecting water at a constant flow rate through a nozzle at the bottom of an immersed granular layer in a Hele-Shaw cell. In a given range of parameters (gr…
[Phys. Rev. E 106, 024901] Published Thu Aug 04, 2022
]]>In this Letter, we report on an experimental study which analyzes the compressive behavior of two-dimensional bidisperse granular assemblies made of soft (hyperelastic) and hard grains in varying proportions ( is the portion of soft grains). By means of a recently developed uniaxial compression set…
[Phys. Rev. E 106, L022901] Published Wed Aug 03, 2022
]]>We measure and analyze the drag force experienced by a rigid rod that penetrates vertically into a granular medium and partially withdraws before sinking again. The drag during the successive reintrusions is observed to be significantly smaller than the force experienced in the first run. Two force …
[Phys. Rev. E 106, 014906] Published Thu Jul 28, 2022
]]>We experimentally study the crack formation and decompaction-wave propagating in a vibrated powder bed consisting of glass beads of 5 in diameter. The vibrated powder bed exhibits three distinct phases depending on the vibration conditions: consolidation (CS), static fracture (SF), and dynamic fr…
[Phys. Rev. E 106, 014905] Published Wed Jul 27, 2022
]]>If a granular material is poured from above on a horizontal surface between two parallel, vertical plates, a sand heap grows in time. For small piles, the grains flow smoothly downhill, but after a critical pile size , the flow becomes intermittent: sudden avalanches slide downhill from the apex t…
[Phys. Rev. E 106, 014904] Published Mon Jul 25, 2022
]]>We present a two-dimensional mesoscopic model of a yield stress material that includes the possibility of local volume fluctuations coupled to shear in such a way that the shear strength of the material decreases as the local density decreases. The model reproduces a number of effects well known in …
[Phys. Rev. E 106, 014903] Published Fri Jul 22, 2022
]]>Penetration of intruders into granular packings is well described by separately considering the dry or wet case of granular environments in previous experiments and simulations; however, the unified description of such penetration depth in these two granular media remains elusive due to lacking clea…
[Phys. Rev. E 106, 014902] Published Wed Jul 20, 2022
]]>The main aim of our work is to explore the effect of particle shape heterogeneity on the dynamics of an intruder moving through a two-dimensional mixture of dumbbells and disks. In spite of similar physical conditions (the mass of the dumbbell is the same as that of the disk) and the same area fract…
[Phys. Rev. E 106, 014901] Published Thu Jul 07, 2022
]]>By means of the direct simulation Monte Carlo method, the effect of rarefaction on the heat fluxes and the hydrodynamics of a granular gas bounded by thermal walls is investigated. The heat flux is found to evolve nonmonotonically with the particle inelasticity due to the competition between the par…
[Phys. Rev. E 105, 064903] Published Wed Jun 29, 2022
]]>Interparticle forces are known to influence mechanical and physical properties of granular materials. A method for inferring forces in two-dimensional and three-dimensional experiments has recently been developed and applied to the problem of examining force statistics, energy dissipation, fracture …
[Phys. Rev. E 105, 064902] Published Mon Jun 27, 2022
]]>By means of discrete-element methods, we investigate the joint effects of the grain size distribution (GSD) and contact friction on the structure of three-dimensional samples composed of spherical grains. Specifically, we compress these systems isotropically until jamming and then analyze their stru…
[Phys. Rev. E 105, 064901] Published Mon Jun 06, 2022
]]>Granular rheology is experimentally investigated in a vertical Couette-Poiseuille-like channel flow of photoelastic disks, where an erodible bed is sheared intermittently by an upward-moving shear band and a gravity-induced reverse flow. The shear band conforms to the existing nonlocal Eyring-like r…
[Phys. Rev. E 105, L052901] Published Thu May 26, 2022
]]>From two-dimensional (2D) numerical simulations of the motion of a circular intruder into a dry granular packing, we provide evidence for a specific force term in the case of unsteady motion in addition to the force corresponding to a steady motion. We show that this additional term is proportional …
[Phys. Rev. E 105, 054903] Published Fri May 20, 2022
]]>We investigate numerically the impact process of a particle of diameter and velocity onto a cohesive granular packing made of similar particles via two-dimensional discrete element method simulations. The cohesion is ensured by liquid bridges between neighboring particles and described by short…
[Phys. Rev. E 105, 054902] Published Thu May 12, 2022
]]>We show how oscillations in fluid flow over a fluid-saturated and porous sediment bed leads to the development of a bedform. To understand the role of pressure fluctuations on the bed associated with flow oscillations, we analyze how the flow penetrates into and through the bed. We then calculate th…
[Phys. Rev. E 105, 054901] Published Thu May 05, 2022
]]>In a uniform layer consisting of a mixture of granular material and liquid, it is known that desiccation cracks exhibit various anisotropic patterns that depend on the nature of the shaking that the layer experienced before drying. The existence of this effect implies that information regarding the …
[Phys. Rev. E 105, 044902] Published Thu Apr 21, 2022
]]>Experiments and simulations of an intruder dragged by a spring through a two-dimensional annulus of granular material exhibit robust force fluctuations. At low packing fractions (), the intruder clears an open channel. Above , stick-slip dynamics develop, with an average energy release that…
[Phys. Rev. E 105, L042902] Published Thu Apr 21, 2022
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