Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlocal strain gradient torsion of elastic beams: variational
  formulation and constitutive boundary conditions   Nonlocal strain gradient continuum mechanics is a methodology widely employed
in literature to assess size effects in nanostructures. Notwithstanding this,
improper higher-order boundary conditions (HOBC) are prescribed to close the
corresponding elastostatic problems. In the present study, it is proven that
HOBC have to be replaced with univocally determined boundary conditions of
constitutive type, established by a consistent variational formulation. The
treatment, developed in the framework of torsion of elastic beams, provides an
effective approach to evaluate scale phenomena in smaller and smaller devices
of engineering interest. Both elastostatic torsional responses and torsional
free vibrations of nano-beams are investigated by applying a simple analytical
method. It is also underlined that the nonlocal strain gradient model, if
equipped with the inappropriate HOBC, can lead to torsional structural
responses which unacceptably do not exhibit nonlocality. The presented
variational strategy is instead able to characterize significantly peculiar
softening and stiffening behaviours of structures involved in modern
Nano-Electro-Mechanical-Systems (NEMS).

11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex