Because of the huge commercial importance of granular systems, the second-most used material in industry after water, intersecting the industry in multiple trades, like pharmacy and agriculture, fundamental research on grain-like materials has received an increasing amount of attention in the last decades. In photonics, the applications of granular materials have been only marginally investigat...

In this work, we first review some general properties of dense granular materials. We are particularly concerned with a statistical description of these materials, and it is in this light that we briefly describe results from four representative studies. These are: experiment 1: determining local force statistics, vector forces, force distributions and correlations for static granular systems; ...

We numerically and theoretically study the macroscopic properties of dense, sheared granular materials. In this process we first consider an invariance in Newton's equations, explain how it leads to Bagnold's scaling, and discuss how it relates to the dynamics of granular temperature. Next we implement numerical simulations of granular materials in two different geometries--simple shear and flo...

this paper discusses the arching effect as the formation of a stable arch in granular materials. for this aim, a developed trapdoor apparatus is designed in order to investigate the arch dimensions in term of the internal friction angle, average size and base angle of materials. observations show that for all tested granular ensembles, width and height of the arch increase with an increase in t...

A zero-temperature critical point has been invoked to control the anomalous behavior of granular matter as it approaches jamming or mechanical arrest. Criticality manifests itself in an anomalous spectrum of low-frequency normal modes and scaling behavior near the jamming transition. The critical point may explain the peculiar mechanical properties of dissimilar systems such as glasses and gran...

Ich versichere, daß ich die Arbeit ohne fremde Hilfe und ohne Benutzung anderer als der angegebenen Quellen angefertigt habe und daß die Arbeit in gleicher oderähnlicher Form noch keiner anderen Prüfungsbehörde vorgelegen hat und von dieser als Teil einer Prüfungsleistung angenommen wurde. Alle Ausführungen, die wörtlich oder sinngemäßübernommen wurden, sind als solche gekennzeichnet. Granular ...

– We present experimental observations of the onset of flow for horizontally vibrated 3D granular systems. For accelerations Γ above Γ, the top layers of granular material flow, leading to convection with motion both parallel and transverse to the shaking; the lower part of the layer moves with the shaker in solid body motion. With increasing Γ, more of the layer becomes liquefied. The initial ...

Granular anisotropy is attributable to many complex behaviors of granular materials and reflects important microstructures at the grain scale, and should be fully considered towards the development of realistic constitutive models for such materials. In this paper, we present a study on the behavior of anisotropy using a three-dimensional Discrete Element Method (DEM). Isotropic packings of san...

The macroscopic mechanical behaviour of granular materials is governed by microscopic features at the particle scale. Photoelasticimetry is a powerful method for measuring shear stresses in particles made from birefringent materials. As a complementary method, we here identify the hydrostatic stress networks through thermoelastic stress analysis using infrared thermographic measurements. Experi...