LAUSR

Abstract In this paper, a sandwich panel composed of two metal face sheets and a three-dimensional (3D) isotropic foam core with negative Poisson's ratio (NPR) was established via FEM. The 3D NPR isotropic foam core was achieved by using triaxial compression method on a cubic Voronoi model, which was created based on Voronoi tessellation technique to achieve different randomness for the core (β). The Poisson's ratio of the Voronoi core dropped rapidly at first, and then increased with an increasing triaxial pre-compression ratio η. A minimum Poisson's ratio, −0.12, was obtained when the randomness of the Voronoi core β = 0.29 and the triaxial pre-compression ratio η = 0.4. The blast resistance of the proposed composite sandwich panel (CSP) with cores that have different β and η under 300 g equivalent TNT explosion was analyzed. Results show that with an increase of η, the maximum stress on the foundation surface of CSPs gradually decreased, and then slightly increased. The maximum stress on the foundation surface of CSPs can reach a minimum value when β = 0.29 and η = 0.4. The proposed CSP with the minimum Poisson's ratio core exhibited the highest blast resistance performance, which was approximately 1.5 times higher than CSP with traditional re-entrant NPR structure core.