Design of a porous material with isotropic negative Poisson's ratio

This paper proposes the design of a two-dimensional porous solid with omni-directional negative Poisson's ratio. The hexagonal periodic distribution of the pores makes the effective behavior isotropic. Both experimental tests and numerical simulations have been performed to determine the effective properties of the porous solid. A parametric study on the effect of the geometrical microstructural parameters is also presented. This auxetic structure is easy to fabricate and can be very useful in several engineering applications.