Numerical Analysis of the Mechanical Properties of 3D Random Voronoi Structures With Negative Poisson's Ratio

3D random Vonoroi structures with negative Poisson's ratio have been proposed and created numerically via finite element method using Voronoi tessellation technique. Negative Poisson's ratio is achieved via triaxial compression treatment on the Voronoi models generated using Matlab. The Poisson's ratio and energy absorption capacity of the triaxially compressed structures have been studied as a function of the geometrical irregularity β and the triaxial compression ratio η in a uniaxial compression setup. Results show that the Poisson's ratio of the structures rapidly decreases from positive to negative and achieved a minimum with an increasing triaxial compression ratio η. The Poisson's ratio exhibited slight increase and quickly saturated with further increase of the triaxial compression ratio η. A minimum νyz of −0.366 is achieved when β = 0.3 and η = 20%; whereas, a minimum νxz of −0.347 is achieved when β = 0.1 and η = 10%. The energy absorption capacity of the structure with a specific initial irregularity factor β decreases with an increasing η. For a specific η, structures with the maximum initial irregularity factor β exhibited the highest energy absorption capacity. A maximum energy absorption capacity is achieved in the model with an initial irregularity factor β of 0.7 and a triaxial compression ratio η of 10%.