EurekaMag.com logo
+ Site Statistics
References:
47,893,527
Abstracts:
28,296,643
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Slowly sheared dense granular flows: crystallization and nonunique final states


, : Slowly sheared dense granular flows: crystallization and nonunique final states. Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics 70(3 Pt 1): 031303-031303

Simultaneous time-resolved measurements of internal structure, granular volume, and boundary shear force are reported for dense granular packing steadily sheared under a fixed normal load. We identify features of the crystallization transition for a deep shear flow, whose height-dependent local mean velocity spans more than five orders of magnitude. This structural change is accompanied by a significant decrease of granular volume and shear force, with a more rapid falloff of particle velocity with depth than occurs in the disordered state. Boundary conditions can have a profound influence on the crystallization of the entire packing. We find that continuously sheared flow can exhibit nonunique final states even under identical boundary conditions; a few cycles of oscillatory pretreatment can initiate states that evolve into either a crystallized or a disordered final state after long-term unidirectional shearing. On the other hand, the disordered state can be stabilized after being sufficiently compacted by unidirectional shear. These experiments raise interesting questions about how prior history is recorded in the internal structure of granular packings, affecting their instantaneous rheology and long-term evolution in response to shear.


Accession: 050325697

PMID: 15524517

DOI: 10.1103/PhysRevE.70.031303

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Polashenski, W.; Zamankhan, P.; Mäkiharju, S.; Zamankhan, P., 2002: Fine structures in sheared granular flows. Computer simulations were used to investigate shear flows of large numbers of viscoelastic, monosized, spherical particles in unbounded and bounded systems with solid fractions ranging from 0.16 to 0.59. A modified hard-sphere model with inelastic...

Zamankhan, P.; Tynjälä, T.; Polashenski, W.; Zamankhan, P.; Sarkomaa, P., 2002: Stress fluctuations in continuously sheared dense granular materials. At high solid concentrations, computer simulations of sheared granular materials comprised of randomly arranged, monodisperse, smooth, inelastic spherical particles flowing in a Couette geometry show large fluctuations in the normal stress at the...

Reddy, K.Anki.; Kumaran, V., 2009: Structure and dynamics of two-dimensional sheared granular flows. The structure and dynamics of the two-dimensional linear shear flow of inelastic disks at high area fractions are analyzed. The event-driven simulation technique is used in the hard-particle limit, where the particles interact through instantaneou...

Kumaran, V., 2006: Velocity autocorrelations and viscosity renormalization in sheared granular flows. The decay of the velocity autocorrelation function in a sheared granular flow is analyzed in the limit where the wavelength of fluctuations is larger than the "conduction length," so that energy is a nonconserved variable. The decay of t...

Wang, P.; Song, C.; Briscoe, C.; Makse, Hán.A., 2008: Particle dynamics and effective temperature of jammed granular matter in a slowly sheared three-dimensional Couette cell. We report experimental measurements of particle dynamics on slowly sheared granular matter in a three-dimensional Couette cell. A closely packed ensemble of transparent spherical beads is confined by an external pressure and filled with fluid to m...

Potiguar, F.Q.; Makse, H.A., 2006: Effective temperature and jamming transition in dense, gently sheared granular assemblies. We present extensive computational results for the effective temperature, defined by the fluctuation-dissipation relation between the mean square displacement and the average displacement of grains, under the action of a weak, external perturbatio...

Kumaran, V., 2005: Kinetic model for sheared granular flows in the high Knudsen number limit. The sheared granular flow of rough inelastic granular disks is analyzed in the high Knudsen number limit, where the frequency of particle-wall collisions is large compared with particle-particle collisions, using a kinetic theory approach. An asym...

Daniels, K.E.; Behringer, R.P., 2005: Hysteresis and competition between disorder and crystallization in sheared and vibrated granular flow. Experiments on spherical particles in a 3D annular shear cell vibrated from below and sheared from above show a hysteretic freezing or melting transition. Under sufficient vibration a crystallized state is observed, which can be melted by sufficie...

Anonymous, 2004: On dense granular flows. The behaviour of dense assemblies of dry grains submitted to continuous shear deformation has been the subject of many experiments and discrete particle simulations. This paper is a collective work carried out among the French research group Group...

Pouliquen, O., 2005: Velocity correlations in dense granular flows. Velocity fluctuations of grains flowing down a rough inclined plane are experimentally studied. The grains at the free surface exhibit fluctuating motions, which are correlated over a few grain diameters. The characteristic correlation length is s...