The light-weight foam filling of metallic columnar structures increases the Specific Absorbed Energy (SAE) values of foam-filled
tubes over those of empty counterparts when appropriate tube geometry, tube wall-foam filler bonding and foam density are
chosen [1–6]. Foam filling usually results in an interaction between tube wall and foam filler, increasing the average crushing loads
of filled-tube over the sum of the crushing loads of foam (alone) and tube (alone). Despite the many experimental investigations
conducted to understand the crushing behavior of foam-filled single metal and empty composite tubes, the crushing behavior
of empty and foam-filled multi-packed and hybrid (metal/composite) tubes have not been investigated as much. In this study,
the quasi-static crushing behavior of empty and Al foam-filled single and two multi-tube designs, hexagonal (Fig.l (a)) and
square packing (Fig. l(b)) and empty and foam-filled hybrid tubes (Fig. l(c)) were investigated.