A novel 3D composite structure with tunable Poisson's ratio and stiffness

KGaA, Weinheim A composite structure with tunable mechanical properties is introduced. The composite consists of matrix material and a stack of inclusions. The specific hollow re-entrant shell inclusions could exhibit ‘expansion effect’ and ‘closure effect’ as responses to tensile and compressive loadings, respectively. Due to the special deformation mechanism of the inclusions, the global structure exhibits unusual properties over a wide range of applied deformations. The overall Poisson's ratio of the composite is significantly reduced comparing with its constituents, and an overall hardening effect is achieved. Moreover, according to the results of a parametric finite element analysis, the specific properties of this composite structure can be tailored by controlling the geometry features and density of the inclusions.