Enhancement of mechanical properties of hollow-strut foams: Analysis

Hollow-strut foams are predicted to have superior mechanical properties compared with solid-strut foams of the same relative density. Due to the enlarged bending stiffness of the hollow strut, the enhancements of stiffness, buckling strength, plastic collapse strength, and brittle failure strength and fracture toughness were substantial (even an order of magnitude) according to the analysis and comparisons. The hollow-strut foam is much more damage tolerant than the solid-strut foam. The enhancement of the robustness to waviness influence is dramatic. The stiffness enhancement of the wavy hollow-strut foam will exceed an order of magnitude. With hollow struts, foams have the comparable (even stiffer and stronger) mechanical properties compared with stretching dominated lattice truss materials.