The auxetic properties of a network of bending beams

The mechanical response of an aggregate of bending beams in two dimensions is investigated. The special mission of this paper is to find auxetic properties (negative Poisson's ratio). A formal correspondence between a contacting granular material and a medium consisting of bending beams is established. The former has already been studied in previous papers and the results can be taken over quite readily. Among the result it is reported that networks of beams that are stubby auxetic behaviour is naturally present, even in a mean field approach. For heterogeneous materials the role of local anisotropies is highlighted as a possible mechanism underlying an overall negative Poisson ratio. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.