arXiv subjects

Jasna Brujic

Publications and source records attributed to Jasna Brujic.

22 records · Page 2Linked to original sources

arXiv2005

Granular dynamics in compaction and stress relaxation

Elastic and dissipative properties of granular assemblies under uniaxial compression are studied both experimentally and by numerical simulations. Following a novel compaction procedure at varying oscillatory pressures, the stress response to a step-strain reveals an exponential relaxation followed by a slow logarithmic decay. Simulations indicate that the latter arises from the coupling between damping and collective grain motion predominantly through sliding. We characterize an analogous "glass transition" for packed grains, below which the system shows aging in time-dependent sliding correlation functions.

cond-mat.soft↗

arXiv2005

Statistical Mechanics of Jammed Matter

A thermodynamic formulation of jammed matter is reviewed. Experiments and simulations of compressed emulsions and granular materials are then used to provide a foundation for the thermodynamics.

cond-mat.soft↗

arXiv2005

A basis for the statistical mechanics of granular systems

This paper aims to justify the use of statistical mechanics tools in situations where the system is out of equilibrium and jammed. Specifically, we derive a Boltzmann equation for a jammed granular system and show that the Boltzmann's analysis can be used to produce a ``Second Law'', $\dot{S}\ge 0$ for jammed systems. We highlight the fundamental questions in this area of physics and point to the key quantities in characterising a packing of particles, accessible through a novel experimentation method which we also present here.

cond-mat.soft↗

arXiv2002

Characterization of the Micromechanics in a Compressed Emulsion System: Force Distributions

The micromechanics of a variety of systems experiencing a structural arrest due to their high density could be unified by a thermodynamic framework governing their approach to 'jammed' configurations. The mechanism of supporting an applied stress through the microstructure of these highly packed materials is important in inferring the features responsible for the inhomogeneous stress transmission and testing the universality for all jammed matter. In this paper we present a novel method for measuring the force distribution within the bulk of a compressed emulsion system using confocal microscopy and explain our results with a simple theoretical model and computer simulations. We obtain an exponential distribution at large forces and a small peak at small forces, in agreement with previous experimental and simulation data for other particulate systems.

cond-mat.soft↗