MODELING NEGATIVE POISSON RATIO EFFECTS IN NETWORK-EMBEDDED COMPOSITES

Novel network structures have been fabricated, and described in earlier papers, that exhibit large negative Poisson ratios. In this paper composite materials are modelled by finite element analysis, that exhibit similar effects. A detailed description is given of the methods required to model the bulk elastic properties of a network-embedded composite. It is shown that a negative Poisson ratio can be produced in such structures provided the ratio of the reinforcement to matrix modulus is large. Simple "rule of mixtures" estimates for the elastic properties are shown to be be totally inappropriate for such complex network microstructures.