  Curved beams are basic structural components of
Nano-Electro-Mechanical-Sistems (NEMS) whose design requires appropriate
modelling of scale effects. In the present paper, the size-dependent static
behaviour of curved elastic nano-beams is investigated by stress-driven
nonlocal continuum mechanics. Axial strain and flexural curvature fields are
integral convolutions between equilibrated axial force and bending moment
fields and an averaging kernel. The nonlocal integral methodology formulated
here is the generalization to curved structures of the treatment in [Int. J.
Eng. Science 115 (2017) 14-27] confined to straight beams. The corresponding
nonlocal differential problem, supplemented with non-standard boundary
conditions, is highlighted and shown to lead to mathematically well-posed
problems of nano-engineering. The theoretical predictions, exhibiting
stiffening nonlocal behaviours, are therefore appropriate to significantly
model a wide range of small-scale devices of nanotechnological interest. The
nonlocal approach is exploited by analytically establishing size-dependent
responses of curved elastic nano-sensors and nano-actuators that are driven by
the small-scale characteristic parameter.
