elastic lattice

In this paper we propose different classes of isotropic microstructured media with tunable Poisson's ratio. The elastic periodic systems are continuous porous media and two- and three-dimensional lattices. The microstructural parameters can be tuned in order to have an effective Poisson's ratio equal to zero. The connection between microstructural parameters and effective properties is shown in detail both analytically and numerically.

Continuous system with null Poisson's ratio:

This paper describes the propagation of an edge crack in a semi-infinite triangular lattice, consisting of identical point masses connected by thermoelastic links. A change of temperature, represented by a time-periodic series of high-gradient temperature pulses, is applied at the boundary of the lattice. In order to make the initial crack advance in the lattice a failure criterion is imposed, whereby the links break as soon as they attain a prescribed elongation.