Thermo-Elastic Homogenization of TPMS-Based Interpenetrating Phase Composites: A Comparison Between Finite Element and Mechanics of Structure Genome Approaches

Triply Periodic Minimal Surface (TPMS)-based Interpenetrating Phase Composites (IPCs) combine two co-continuous solid phases across a smooth, doubly curved interface, providing a multifunctional design space for tailoring mechanical and thermal properties. This study investigates the effective thermo-elastic and thermal-transport behavior of TPMS-based IPCs using two homogenization approaches: Finite Element (FE)-based Representative Unit Cell (RUC) homogenization and Mechanics of Structure Genome (MSG)-based homogenization. Four TPMS topologies – gyroid, diamond (Schwarz D), PMY, and F-Rhombic Dodecahedron (F-RD) – are considered over relative densities ranging from 0.1 to 0.5. Conforming-mesh RUC models are generated using Microgen and analyzed in Abaqus for FE simulations with periodic boundary conditions, and in the in-house CmbsFE code for MSG-based homogenization. The two approaches are assessed for predicting effective elastic properties, coefficients of thermal expansion (CTEs), and thermal conductivities. The study further examines the influence of TPMS topology and relative density on the multifunctional response of two-phase IPCs, supporting the design and optimization of lightweight structural–thermal materials.