Thermal conductivities of iso-volume centre-symmetric honeycombs

The paper describes the equivalent thermal conductivities of iso-volume periodic honeycomb concepts with 3 and 4-connectivities along the in-plane and out-of-plane principal directions. A centre-symmetric 3-connectivity hexagonal layout and a centre-symmetric 4-connectivity cross-chiral configuration are considered. Analytical closed-form solutions of the equivalent thermal conductivities are derived and compared against Finite Element simulations, providing an excellent match. Parametric analyses show the influence of several geometry parameters of the unit cells over the homogenised thermal conductivities along the three principal directions. The analysis shows the capability of tailoring the core geometrical parameters of these iso-volume honeycomb concepts to achieve a desired thermal response in structural sandwich panels or core fillers, for which the coupled thermo-mechanical performance is paramount.