Strain Rate Effect on Mechanical Properties of the 3D-Printed Metamaterial Foams With Tunable Negative Poisson’s Ratio

As a kind of metamaterial, the negative Poisson’s ratio foams, which expand (shrink) in transverse direction when stretched (compressed) longitudinal direction, have many potential applications fields such as aerospace and mechanical biomedical engineering. In this paper, out-of-plane crushing behaviors four types orthogonal isotropic NPR convex-concave foams (CCF) were extensively studied using an electronic universal testing machine Instron at different strain rates where each test was conducted constant compressive velocity under uniaxial compression. Strain rate effect on properties these is experimentally studied. When increases, force enhancement obvious varies with specimens. The difference energy absorption deformation patterns for between quasi-static dynamic loading conditions also analyzed. We find that specimens are not only related to velocities but topologies research paper expected be meaningful optimization design foam structures/materials widely used