Kyburz, M L Sovilla, B Gaume, J Ancey, C
Published in
Granular matter
The calculation of the impact pressure on obstacles in granular flows is a fundamental issue of practical relevance, e.g. for snow avalanches impacting obstacles. Previous research shows that the load on the obstacle builds up, due to the formation of force chains originating from the obstacle and extending into the granular material. This leads to...
Fonceca, I. Hidalgo, R. C. Maza, D.
Published in
Granular Matter
In the present work, we investigate experimentally and numerically the motion of solid macroscopic spheres (Brownian and colloidal effects are negligible) when settling from rest in a quiescent fluid toward a solid wall under confined and unconfined configurations. Particle trajectories for spheres of two types of materials are measured using a hig...
Méjean, Ségolène Guillard, François Faug, Thierry Einav, Itai
Published in
Granular Matter
AbstractFlows of dry granular materials on a smooth chute are investigated by X-ray radiography. Discontinuities in height, velocity and density, namely jumps, are produced under different incoming steady-flow conditions by varying the mass discharge and the slope angle. This allows to confirm and further reveal the phase-diagram of standing granul...
Wang, Xiaoliang Li, Ge Liu, Qingquan
Published in
Granular Matter
AbstractThe open question of granular solid–fluid transition plays an important role in both modeling natural hazards and industrial particulate process. The well-developed critical state plasticity theory for granular solids and μ(I)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \...
Suhr, Bettina Skipper, William A. Lewis, Roger Six, Klaus
Published in
Granular Matter
Despite ongoing research, the parametrisation of a DEM model is a challenging task, as it depends strongly on the particle shape representation used, particle-particle contact law and the simulated applications: for railway ballast e.g. lab tests or track conditions. The authors previously modelled railway ballast with a DEM model using a simple pa...
Maroof, M. Ali Mahboubi, Ahmad Vincens, Eric Noorzad, Ali
Published in
Granular Matter
The minimum and maximum void ratios (emin and emax, respectively) of soils are intrinsic soil properties related to their particle size distribution (PSD) and particle shape. Different attempts have been made to predict these reference void ratios for cohesionless soils through the involved particle morphology. However, these predictive models do n...
Espinosa, M. Díaz-Melián, V. Serrano-Muñoz, A. Altshuler, E.
Published in
Granular Matter
When a cylindrical object penetrates granular matter near a vertical boundary, it experiences two effects: its center of mass moves horizontally away from the wall, and it rotates around its symmetry axis. Here we show experimentally that, if two identical intruders instead of one are released side-by-side near the wall, both effects are also detec...
Lehman, Susan Y. Christman, Lilianna E. Jacobs, D. T. Johnson, Nathan S. D. E. F. Palchoudhuri, Paroma Tieman, Catherine E. Vajpeyi, Avi Wainwright, Elliot R. Walker, Justine E. Wilson, Ian S.
...
Published in
Granular Matter
Universal aspects of the effect of cohesion are explored by a combination of experiments and modeling. Experimentally, we observe the avalanching behavior of a granular bead pile while varying the cohesion, and we find these experimental results to be closely matched by the results of a simple theoretical model of a completely different system. In ...
Götz, Holger Santarossa, Angel Sack, Achim Pöschel, Thorsten Müller, Patric
Published in
Granular Matter
Granular jamming has been identified as a fundamental mechanism for the operation of robotic grippers. In this work, we show, that soft particles like expanded polystyrene beads lead to significantly larger gripping forces in comparison to rigid particles. In contradiction to naive expectation, the combination of jamming and elasticity gives rise t...
Eric, Breard C. P. Luke, Fullard Josef, Dufek Michael, Tennenbaum Alberto, Fernandez-Nieves Jean-François, Dietiker
Published in
Granular Matter
Natural geophysical mass flows are among the most complex granular systems and their dynamics are often modified by the presence of an interstitial fluid. Prediction of their runout requires the development of models estimating the solid stresses in these hazardous currents wherein excess pore-fluid pressure can develop. We use discrete element mod...
