Effective conductivities and elastic moduli of novel foams with triply periodic minimal surfaces

Triply periodic minimal surfaces (TPMS) are employed to create novel cellular materials. They include Schwarz Primitive, Schoen IWP, Neovius, Schoen Gyroid, Fischer-Koch S, and Schwarz CLP geometries. Unit cells are studied using a finite element method with periodic boundary conditions in order to predict effective electrical/thermal conductivities and elastic moduli of these TPMS-based foams. The conductivities vary linearly with relative density. The conductivities of the Primitive-, IWP-, Neovius-, Gyroid-, and S-foams are very close to each other. The conductivity of the CLP-foam needs to be described by two values because of its geometrical asymmetry while the other foams are found to be isotropic when their conductivities are studied. The uniaxial, shear and bulk moduli, Poisson ratio and elastic anisotropy of these TPMS-foams are also computed and compared. When the mechanical properties are investigated, the CLP-foam is found to have highest anisotropy among the considered TPMS-foams. In addition, the Primitive-foam possesses highest shear modulus while the Neovius, IWP-, and Primitive-foams possess highest bulk moduli among the TPMS-foams.