Issue
EPL
Volume 87, Number 1, July 2009
Article Number 18004
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/87/18004
Published online 17 July 2009
EPL, 87 (2009) 18004
DOI: 10.1209/0295-5075/87/18004

The effective Poisson ratio of random cellular matter having bending dominated architecture

A. Bhaskar

Aeronautics & Astronautics, School of Engineering Sciences, University of Southampton - SO17 1BJ, Southampton, UK, EU

A.Bhaskar@soton.ac.uk

received 10 February 2009; accepted in final form 16 June 2009; published July 2009
published online 17 July 2009

Abstract
We argue that the effective Poisson ratio of cellular and porous solids is independent of the material of the solid phase, if the mechanism of the cell wall deformation is dominated by beam bending —thus rendering it to be a purely kinematic quantity. Introducing a kinematic simplification and requiring statistical isotropy, we prove a result of remarkable generality that the effective Poisson ratio of irregular planar structures equals 1 for all bending dominated random architectures. We then explore a deeper connection of this behavior with area-preserving deformation of planar closed elastic cells. We show that thin sheets and films made of such microstructured material afford physical realizations of the two-dimensional analogue of incom- pressible matter. We term such non-stretchable sheet material as well as deformations as isoektasic.

PACS
81.05.Rm - Porous materials; granular materials.
61.43.-j - Disordered solids.
62.20.dj - Poisson's ratio.

© EPLA 2009