Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ratcheting of granular materials   We investigate the quasi-static mechanical response of soils under cyclic
loading using a discrete model of randomly generated convex polygons. This
response exhibits a sequence of regimes, each one characterized by a linear
accumulation of plastic deformation with the number of cycles. At the grain
level, a quasi-periodic ratchet-like behavior is observed at the contacts,
which excludes the existence of an elastic regime. The study of this slow
dynamics allows to explore the role of friction in the permanent deformation of
unbound granular materials supporting railroads and streets.

19
The categories of this paper are: eess
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int