Dynamic Deformation Mechanisms and Mechanical Properties of Additively Manufactured Closed-Cell Foams of Various Topologies

Closed-cell foams are widely used in energy absorption and load-bearing applications. Herein, four lightweight closed-cell foam topologies—tetrakaidecahedron, octet, spherical, and reverse hexagonal—are designed, manufactured, and mechanically tested. The structures are fabricated from acrylonitrile butadiene styrene using fused deposition modeling and subjected to low-velocity impact to investigate their elastic, plastic, and energy absorption behavior under dynamic loading. Deformation mechanisms are investigated to explore the role of topological architectures on mechanical response. Among the structures, the reverse hexagonal topology exhibits the highest yield strength and elastic stiffness, making it suitable for load-bearing applications. However, it demonstrates poor energy absorption due to its inability to utilize joints as plastic hinges during impact. In contrast, the octet structure exhibits superior energy absorption through a layer-by-layer collapse mechanism but offers limited elastic properties. The formation of shear bands in tetrakaidecahedron structure leads to midrange elastic properties. The spherical structure, however, shows poor energy absorption due to its unsystematic deformation and cell-wall distortion. The tetrakaidecahedron foam shows increased strength but reduced energy absorption during impact compared to quasi-static compression. These findings highlight the importance of considering dynamic mechanical properties when designing structures for impact-prone applications throughout their service life.