  New lattice model for the gradient elasticity is suggested. This lattice
model gives a microstructural basis for second-order strain-gradient elasticity
of continuum that is described by the linear elastic constitutive relation with
the negative sign in front of the gradient. Moreover the suggested lattice
model allows us to have a unified description of gradient models with positive
and negative signs of the strain gradient terms. Possible generalizations of
this model for the high-order gradient elasticity and three-dimensional case
are also suggested.
