Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stress propagation in granular media: Breaking of any constitutive state
  equation relating local stresses together by a change of boundary conditions   The stress response of a granular assembly subject to different changes of
boundary conditions is studied experimentally in order to define the stress
propagation characteristics. These results demonstrate that no simple and
single relationship between local stresses exists, which would be imposed by
the local structure of the granular assembly only in general. On the contrary,
it is demonstrated that these results are controlled by the boundary conditions
themselves and that a tiny change of them may lead to strong variations in the
incrememental stress relation; furthermore, in other cases, these changes may
generate large variations of the stress field and can allow to understand
partly the fluctuations already observed in these media. PACS: 46.10+z ;
46.30.-i ; 81.05.Rm

36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an