Modelling and testing of a foldable macrostructure exhibiting auxetic behaviour

Abstract Auxetics exhibit the anomalous property of getting fatter rather than thinner when uniaxially stretched [negative Poisson's ratio (NPR)]. This paper presents an analytical model of a structure constructed from umbrella type sub‐units which is predicted to exhibit this property together with the results of mechanical tests of a structure having this geometry. It is shown that such systems can exhibit negative on‐axis Poisson's ratio of −1 which means that they maintain their aspect ratio, while Poisson's ratio becomes less negative for loading off‐axis. It is also shown that this model can explain the sign and anisotropy of Poisson's ratio demonstrated by a molecular level system constructed from calix(4)arenes having the same geometry.