Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-static incremental behavior of granular materials: elastic-plastic
  coupling and micro-scale dissipation   The paper addresses a common assumption of elastoplastic modeling: that the
recoverable, elastic strain increment is unaffected by alterations of the
elastic moduli that accompany loading. This assumption is found to be false for
a granular material, and discrete element (DEM) simulations demonstrate that
granular materials are coupled materials at both micro- and macro-scales.
Elasto-plastic coupling at the macro-scale is placed in the context of
thermomechanics framework of Tomasz Hueckel and Hans Ziegler, in which the
elastic moduli are altered by irreversible processes during loading. This
complex behavior is explored for multi-directional loading probes that follow
an initial monotonic loading. An advanced DEM model is used in the study, with
non-convex non-spherical particles and two different contact models: a
conventional linear-frictional model and an exact implementation of the
Hertz-like Cattaneo-Mindlin model. Rectilinear true-triaxial probes were used
in the study (i.e., no direct shear strain), with tiny strain increments of
$2\times 10^{-6}$. At the micro-scale, contact movements were monitored during
small increments of loading and load-reversal, and results show that these
movements are not reversed by a reversal of strain direction, and some contacts
that were sliding during a loading increment continue to slide during reversal.
The probes show that the coupled part of a strain increment, the difference
between the recoverable (elastic) increment and its reversible part, must be
considered when partitioning strain increments into elastic and plastic parts.
Small increments of irreversible (and plastic) strain and contact slipping and
frictional dissipation occur for all directions of loading, and an elastic
domain, if it exists at all, is smaller than the strain increment used in the
simulations.

34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys