Mechanical property analysis and experimental demonstration of zero Poisson’s ratio mixed cruciform honeycomb

Out-of-plane bending stiffness of cruciform honeycomb is too low to hold the panel in a horizontal direction. In this regard, zero Poisson's ratio mixed cruciform honeycomb, a novel structure with new topology, is proposed in this paper. Ribs were designed between monolayer core boards in cruciform honeycomb to restrict the displacement in the 1-direction (vertical to ribs) and enhance the stiffness in the 2-direction (parallel to ribs) simultaneously. Elastic constants, which characterize in-plane mechanical properties, were studied through theoretical calculation and numerical simulation. Experiments have also been performed to validate the analytic models, which showed good correlation with analytical formulas and excellent deformable capacity of the mixed cruciform honeycomb. The uniaxial deformability and out-of-plane bearing capacity of the new model improve obviously compared with cruciform honeycomb. By analyzing the relationship between mechanical properties and cell shape parameters, zero Poisson's ratio mixed cruciform honeycomb can be optimized to meet the deform requirements. In addition, the limitation of compression deformability caused by shapes was analyzed to ensure the effectiveness of the structure, and the results that structural density varies with parameters were given as a design reference according to lightweight requirement. To show the superiority of the new model, a comparison between mixed cruciform honeycomb and hybrid cellular honeycomb was developed in terms of in-plane and out-of-plane mechanical properties.