Modeling of the Mechanical Properties of a Polymer-metal Foam Hybrid

A hybrid material created by mechanically combining polymers and aluminum foams is modeled and analyzed. The hybrid is manufactured by injection molding a polymer (polypropylene and acetal) into the open cells of Duocel® aluminum foam. Prior experimental work revealed that the combination of the polymer and the metal foam yields a hybrid that is stiffer than the polymer alone but has a reduced ultimate tensile strength. A finite element model using a tetrakaidecahedral unit cell is used to model the metal foam ligaments with the polymer occupying the remaining space. The resulting conclusions are that the aluminum ligaments oriented along the load direction cause an increase in stiffness but ligaments oriented laterally cause stress concentration that yield lower strength. The finite element model is used to give both qualitative and quantitative explanations of the physics of the interrelations between the metal foam and the polymer.