Origami-inspired polyhedral cores promise lightweight, deployable sandwich panels with exceptional specific stiffness, yet the role of folding kinematics in energy absorption remains insufficiently examined. This work designs, fabricates, and tests flexible polyhedral sandwich structures via material extrusion printing (MEX) by investigating two multi-material combinations: TPU-PLA and SMP-ABS. Four polyhedral facet-fold topologies were designed, which are truncated-icosidodecahedron (Core 1), rhombicosidodecahedron (Core 2), rhombicuboctahedron (Core 3), and rhombic dodecahedron (Core 4), and benchmarked through quasi-static compression, low-velocity impact, and recovery testing. The cyclic compression results showed stabilization after the second cycle. The variation between subsequent cycles remains below 5%. This indicates that most microstructural changes occurred early in the loading history. In the stabilized regime, topology strongly influenced performance. The rhombicuboctahedron (Core 3) exhibits the highest stiffness of 205 N/mm and energy dissipation up to 16.9 J in the first compression cycle. In contrast, the rhombic dodecahedron (Core 4) provides the most stable, low-loss response. Geometric scaling also affected performance. Reducing the unit-cell size by half leads to a significant reduction in dissipated energy. This confirms that energy absorption does not scale linearly with geometry. Material selection governed cyclic and recovery behavior. TPU-PLA cores show greater hysteresis and damping, whereas SMP-ABS cores recover over 90% of their original height after extreme compression. These findings demonstrate how geometry, fold configuration, and material stiffness combine to govern strain-energy storage and dissipation, offering guidance for 3D- and 4D-printed tunable energy absorbing structures. • 3D and 4D Printed Multi-material Polyhedral Sandwich Structures were analyzed under Compression and Impact Loads. • Polyhedral geometry, not volume fraction, governs stiffness, damping, recovery, and impact response. • Scaling polyhedral unit-cell size shows non-linear energy absorption. • TPU cores dissipate impact energy via viscoelastic compaction, avoiding brittle failure. • SMP cores achieve over 90% shape recovery, enabling deployable 4D lattices.
Alabdouli et al. (Wed,) studied this question.
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