https://doi.org/10.1140/epje/s10189-021-00145-3
Regular Article - Flowing Matter
Aspects of bulk properties of amorphous jammed disks under isotopic compression
1
Institute of Physics, Guizhou University, 550025, Guiyang, Guizhou, China
2
College of Computer Science and Technology, Guizhou University, 550025, Guiyang, China
Received:
14
September
2021
Accepted:
1
November
2021
Published online:
18
November
2021
By investigating the bidisperse disks under isotropic compression, we show the importance of non-affine deformation on the bulk properties of jammed disordered matter and how the mechanical properties are affected by the variation of microscopic quantities with the excess volume density and the friction coefficient
. In theory, we derive a simple formula for the pressure of disk packings which sets up a bridge between the pressure and other statistical quantities like the contact number density and the average normal force. This pressure formula is used to derive the reduced pressure
and the reduced bulk modulus
for disk packings with linear interactions and under affine compression without new contacts. Combining theoretical formulae with Discrete Element Method (DEM) simulations, we investigate the average contact number
and the average reduced overlap
and give the analysis on how
and
are affected by the variation of Z and
. For frictionless disk packings, we find that the affine assumption causes large deviation on Z and
relative to those of non-affine compression and therefore fails to predict the quantitative results of
. For packings with a fixed
, due to the non-affine deformation,
varies approximately linear with the increasing
and Z increases sharply near the jamming point and then approaches a saturation value. With a fixed
and the increasing
,
changes by a small amount while Z presents obvious decrease. The decrease of Z causes the decrease of the slope of function
and the value of
at a fixed
.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021