Compressive behavior and deformation mechanism of 3D-printed negative poisson’s ratio lattice-frame materials

Lattice-frame sandwich structures are widely used due to lightweight, high specific strength and potential multifunctions. The additive manufacturing technology further expends their designability and applicability in modern manufacturing industry, better realizing the integration of design, manufacturing and function. The reentrant lattice-frame materials generally show special negative Poisson’s ratio behavior and excellent energy absorption characteristics. In this paper, a 3D NPR lattice-frame sandwich structure is constructed by the orthogonal arrangement of 2D reentrant hexagonal honeycomb using the selective laser sintering 3D-printing. The reusable parent material and printing quality are characterized. The mechanical behaviors and fracture morphology of printing specimens are studied to explore the interlayer mechanism and potential effect of layer-by-layer printing. The uniaxial compression behaviors and energy absorption characteristics of NPR lattice-frame structures are analyzed by experimental and numerical methods. The influences of geometric parameters on mechanical property and failure mode are revealed. The negative Poisson’s ratio effect released during the deformation evolution of the structure can obviously improve the defamation tolerance and energy-absorbing capability.