The correlation between contact forces and the texture of a packing rigid particles subject to biaxial compression is analyzed by means numerical simulations. Four different aspects are investigated: stress tensor, dissipation due friction, angular distribution forces, fabric tensor characterizing anisotropy texture. All them provide evidence that network can be decomposed unambiguously into two subnetworks with complementary mechanical properties.

Relying on contact dynamics simulations, we study the statistical distribution of forces inside a confined packing circular rigid disks with solid friction. We find following: (1) The number normal and tangential lower than their respective mean value decays as power law. (2) higher exponentially. (3) ratio friction to force is uniformly distributed uncorrelated force. (4) When normalized respect values, these distributions are independent sample size particle distribution.

We investigate shear strength properties of wet granular materials in the pendular state (i.e., where liquid phase is discontinuous) as a function water content. Sand and glass beads were wetted tested direct cell under various confining pressures. In parallel, we carried out three-dimensional molecular dynamics simulations by using an explicit equation expressing capillary force interparticle distance, bridge volume, surface tension. show that, due to peculiar features interactions, major...

We investigate highly polydisperse packings subjected to simple shear by contact dynamics simulations. A major unsolved issue is how granular texture and force chains depend on the size polydispersity far they influence strength. The numerical treatment was made possible ensuring statistical representativity of particle classes. An unexpected finding that internal friction angle independent polydispersity. show this behavior related two mechanisms underlying stability chains: (i) class...

We analyze particle velocity fluctuations in a simulated granular system subjected to homogeneous quasistatic shearing. show that these share the following scaling characteristics of fluid turbulence spite their different physical origins: (i) scale-dependent probability distribution with non-Gaussian broadening at small time scales; (ii) spatial power spectrum field showing power-law decay, reflecting long-range correlations and self-affine nature fluctuations; (iii) superdiffusion...

We present the results of a systematic numerical investigation force distributions in granular packings. find that all main features transmission previously established for two-dimensional systems hard particles hold three-dimensional and soft particles, too. In particular, probability distribution normal forces falls off exponentially above mean force. For below mean, this is either decreasing power law when system far from static equilibrium, or nearly uniform at agreement with recent...

We present a numerical analysis of the effect particle elongation on quasistatic behavior sheared granular media by means contact dynamics method. The shapes are rounded-cap rectangles characterized their elongation. macroscopic and microstructural properties several packings subjected to biaxial compression analyzed as function find that shear strength is an increasing linear Performing additive decomposition stress tensor based harmonic approximation angular dependence branch vectors,...

By means of contact dynamic simulations, we investigate the network topology and force chains in two-dimensional packings elongated particles modeled by rounded-cap rectangles. The morphology large quasistatic equilibrium is complex due to combined effects local nematic ordering orientations contacts between particles. We show that particle elongation affects distributions force/fabric anisotropy via various structures allowed steric exclusions requirement balance. As a result, become...

We perform a detailed analysis of the contact force network in dense confined packing pentagonal particles simulated by means dynamics method. The effect particle shape is evidenced comparing data from pentagon and with identical characteristics, except for circular particles. A counterintuitive finding this work that, under steady shearing, develops lower structural anisotropy than disk packing. show that weakness compensated higher anisotropy, leading to enhanced shear strength revisit...

Using contact dynamics simulations, we compare the effect of rolling resistance at contacts in granular systems composed disks with angularity regular polygonal particles. In simple shear conditions, consider four aspects mechanical behavior these steady state: strength, solid fraction, force and fabric anisotropies, probability distribution forces. Our main finding is that, based on energy dissipation associated relative rotation between two particles contact, can explicitly be identified...

We present a systematic numerical investigation of the shear strength and structure granular packings composed irregular polyhedral particles. The angularity particles is varied by increasing number faces from 8 (octahedronlike shape) to 596. find that increases with up maximum value saturates as become more angular (below 46 faces). At same time, packing fraction peak but declines for analyze connectivity anisotropy microstructure considering both contacts branch vectors joining particle...

We investigate a class of granular materials characterized by the possibility interlocking between particles. The is modeled its effect through rolling resistance depending on relative rotation and normal force at contact points involving single parameter analogous to sliding friction coefficient. model, which introduced in framework dynamics method, applied simulate simple shear large sample. present detailed analysis regarding influence parameters macroscopic response terms strength,...

We present a systematic investigation of the morphology and space-filling properties polydisperse densely packed granular media in two dimensions. A numerical procedure is introduced to generate collections circular particles with size distributions variable shape span constrained by explicit criteria statistical representativity. characterize domain statistically accessible distribution parameters for bounded number particles. This particle generation used different deposition protocols...

We analyze inertial granular flows and show that, for all values of the number I, effective friction coefficient μ arises from three different parameters pertaining to contact network force transmission: (1) anisotropy, (2) chain (3) mobilization. Our extensive 3D numerical simulations reveal that increases with I mainly due an increasing anisotropy partially by mobilization whereas chains declines as a result destabilizing effect particle inertia. The undergoes topological transitions,...

Abstract Granular flows are omnipresent in nature and industrial processes, but their rheological properties such as apparent friction packing fraction still elusive when inertial, cohesive viscous interactions occur between particles addition to frictional elastic forces. Here we report on extensive particle dynamics simulations of complex for a model granular system composed perfectly rigid particles. We show that, the normalized by cohesion-dependent quasistatic values, they governed...

Granular materials are the most recurrent form of solid-state matter on Earth. They challenge researchers and engineers in various fields not only because they occur with a broad variety grain sizes, shapes interactions nature industry, but also show rich panoply mechanical states. Despite this polymorphism, all these different types soils, powders, granules, ores, pharmaceutical products, etc., instances granular same least common denominator being sandlike (psammoid Greek), i.e., solid...

We analyze the effects of particle shape angularity on macroscopic shear behavior and texture granular packings simulated by means contact dynamics method. The particles are regular polygons with an increasing number sides ranging from 3 (triangles) to 60. analyzed in steady state terms their strength, packing fraction, connectivity, fabric force anisotropies, as functions angularity. An interesting finding is that strength increases up a maximum value saturates become more angular (below...

We investigate the effect of an ambient fluid on dynamics collapse and spread a granular column simulated by means contact method interfaced with computational dynamics. The runout distance is found to increase as power law aspect ratio column, and, surprisingly, for given packing fraction, it may be similar in grain-inertial fluid-inertial regimes but considerably longer duration latter case. show that viscous both reduce kinetic energy during enhance flow lubrication spread. Hence, below...

By means of extensive contact dynamics simulations, we analyze the combined effects polydispersity both in particle size and shape, defined as degree shape irregularity, on shear strength microstructure sheared granular materials composed pentagonal particles. We find that is independent span, but unexpectedly, it declines with increasing polydispersity. At same time, solid fraction an function span Hence, densest loosest packings have strength. scale particles their contacts, connectivity...

This paper presents two-dimensional simulations of the flow granular materials in viscous fluids. The authors show that, spite different variables involved, behavior system can be characterized with one single viscoinertial number.