Design, Fabrication and Mechanical Characterization of Pyramidal Periodic Cellular Metal/Polyurethane Foam Hybrid Materials

Abstract

A new type of hybrid material was designed and fabricated by reinforcing periodic cellular metals (PCMs) with rigid polyurethane (PU) foams. A pyramidal PCM geometry and various densities of two-phase rigid polyurethane foam were used to fabricate three different hybrid materials. These novel hybrid materials may find useful application as cores in sandwich structures. By increasing the density of the polyurethane foam used in the PCM/PU foam hybrids, the stiffness of the hybrid increased allowing the stiffness to be tailored for a specific application. Furthermore, the strength of the hybrids was greater than that of the PCM or foam alone, and in most configurations the strength was greater than the sum of the strength of the PCM and the polyurethane foam. Next, the resilience of the hybrids was greater than that of the PCM or foam alone and was also greater than the sum of the resilience of the PCM and foam. Finally, the impact energy at which surface failure would occur was greater in the hybrid samples than the foams or the PCM and was found to increase with increasing foam density.