On the auxetic properties of generic rotating rigid triangles

作者：Grima Joseph N^*; Chetcuti Elaine; Manicaro Elaine; Attard Daphne; Camilleri Matthew; Gatt Ruben; Evans Kenneth E

来源：Proceedings of the Royal Society A-Mathematical Physical and Engineering Sciences, 2012, 468(2139): 810-830.

DOI：10.1098/rspa.2011.0273

• auxetic
• negative Poisson%26apos
• s ratio
• analytical model
• foams
• relative surface density

Materials having a negative Poisson%26apos;s ratio (auxetic) get fatter rather than thinner when uniaxially stretched. This phenomenon has been often explained through models that describe how particular geometric features in the micro or nanostructure of the material deform when subjected to uniaxial loads. Here, a new model based on scalene rigid triangles rotate relative to each other will be presented and analysed. It is shown that this model can afford a very wide range of Poisson%26apos;s ratio values, the sign and magnitude of which depends on the shape of the triangles and the angles between them. This new model has the advantage that it is very generic and may be potentially used to describe the properties in various types of materials, including auxetic foams and their relative surface density. Specific applications of this model, such as a blueprint for a system that can exhibit temperature-dependent Poisson%26apos;s ratios, are also discussed.

• 出版日期2012-3-8