Relaxation response of space lattices in the cubic system designed with architected strut, plate, and shell structural ligaments

The mechanical properties of the architected cellular materials depend on the properties of solid material, relative density, and microstructural geometry and their configurations. In this study, the viscoelastic properties of cellular structures have been studied using material properties of Polyamide PA2200 in the time domain. The cubic lattice structure such as simple cubic (SC), body-centered cubic (BCC) and face-centered cubic (FCC) are designed with tube, plate, and truss as structural ligaments. Numerical homogenization was performed on the unit cells and analyzed for viscoelastic properties under uniaxial, bulk and shear boundary conditions as a function of relative volumes. Stiffer lattices demonstrated weak damping properties. BCC tube-lattices appear to be stiffer against uniaxial and bulk loads than SC and FCC lattices while in case of shear loads, they appeared to be less stiff. FCC plate-lattices seem to be less stiff against uniaxial and bulk loads than SC and BCC structures while they appeared stiffer against shear loads. SC truss-lattices appeared less stiff against uniaxial and bulk loads while stiffer against shear loads. All structural ligaments constituting SC structures have almost same stiffness against uniaxial loads while plate element SC lattice appeared less stiff against shear load and stiffer against bulk load. Truss element BCC lattices have more resistance against uniaxial loads and less resistance against bulk loads while all structural element BCC lattices have almost same stiffness against shear loads. Plate element FCC lattices seem to be less stiff against uniaxial loads while less stiff against shear loads.