Study on the mechanical properties of CFRP composite auxetic structures consist of corrugated sheets and tubes

In recent years, auxetic (negative Poisson's ratio) structures have attracted great attention because of their nonconventional behaviour. However, auxetic structures are usually characterized by low stiffness, which limits their application. Once, their stiffness can be improved, their application field will be significantly broadened. In addition, most auxetic structures are difficult to be produced due to their complex geometries. To solve these two problems, high-performance carbon fibre reinforced polymer (CFRP) composites are used to manufacture an auxetic structure consist of corrugated sheets and tubes. The mechanical properties of the composite auxetic structure consist of corrugated sheets and tubes (CorTube) are studied by experiments, finite element simulation and theory analysis. The results show that, the composite CorTube structures display obvious negative Poisson's ratio effect in large compression strain range, and the auxetic characteristics of the composite CorTube structures become more notable with the increase of the compression strain. The stiffness of the structure depends on the thickness of the corrugated sheets in small strain stage, while the material parameters of the tubes plays determining role in large strain stage. Finally, the deformation characteristics and failure modes of the CorTube during the compression process are discussed.