Time dependent response of architectured Neovius foams

This study presents the viscoelastic behavior of an architectured foam based on the mathematically-known Neovius (N) triply periodic minimal surface (TPMS) under both time and frequency domains. Recent computational studies showed that N-based architectures possess unique multifunctional attributes when used as a three-dimensional (3D) reinforcement in composites. Here, 3D representative volume elements (RVEs) of different relative densities (i.e., the ratio of the foam's density to the density of its solid counterpart) were generated and studied using the finite element method in order to predict the effective uniaxial, shear, and bulk viscoelastic responses of N-foams as a function of relative density and/or frequency. The principle of time-temperature superposition principle was used to create the master curve of the observed relative-density dependent mechanical responses (loss tangent, storage and loss moduli) in frequency domains. Reduced uniaxial, bulk and shear stiffness-loss map results suggested that the N-foam possesses strongest uniaxial viscoelastic response while highest damping can be achieved under shear responses. Relaxation behavior of N-foam was compared with other seven different types of open-cell periodic foams. It was found that N-foam shear response is similar to Reinforced Body Centered Cubic (RBCC) foam and possesses highest bulk and uniaxial relaxation responses. Among these foams, we found that N-foam is the best candidate to use as a damper under shear loading conditions however best to be used as light weight stiffener under uniaxial and bulk loadings.