Mechanical Properties of Porous Metallic and Natural Foams

Foams with porous structures exhibited excellent mechanical properties. In this study, foams made from metals and natural materials were investigated using a combination of experiments and mathematical modeling. For aluminum foams, mechanical tests using individual foam struts were performed to extract essential material properties. Results indicated that the micro-strut tensile strength and ductility were much higher than corresponding bulk alloy with the same treatment. Four-strut models were used to probe the detail failure mechanisms of foam microstructures under compression. As a natural foam, turtle shells exhibited a sandwiched structure made from dense cortical bones and porous trabecular bones. A combination of experimental, analytical, and computational study was performed to probe the mechanical behavior of turtle shells at the nano-, micro- and macro-scales. The results indicated that turtle shells were effective in confining the deformation and stress within the porous structures. Learnings from these studies could provide essential guidance to the creation of bio-inspired porous foams.