  A numerical study on the elastic response of single- and multi-layer systems
formed by alternating pentamode lattices and stiffening plates is presented.
Finite element simulations are conducted to analyze the dependence of the
effective elastic moduli of such structures upon suitable aspect ratios, which
characterize the geometry of the generic pentamode layer at the micro- and
macro-scale, and the lamination scheme of the layered structure. The given
numerical results highlight that the examined structures exhibit
bending-dominated response, and are able to achieve low values of the effective
shear modulus and, contemporarily, high values of the effective compression
modulus. We are lead to conclude that confined pentamode lattices can be
regarded as novel metamaterials that are well suited for seismic isolation and
impact protection purposes. Their elastic response can be finely tuned by
playing with several geometrical and mechanical design variables.
