Advancement in additive manufacturing technologies helped researchers design and fabricate
cellular structures. Cellular structures possess lightweight and desirable mechanical properties.
One such structure is called “auxetic” structures. “Auxetics” is the term used for structures that
exhibit negative Poisson’s ratio. These structures exhibit unique properties such as lateral
contraction under axial compression or lateral expansion under axial tension. Such behavior
helped it find applications in medicine (stents), sports, robotics, etc. The auxetic response is a
result of the deformation behavior of the individual unit cell. The design of the unit cell
influences the overall performance of auxetic structures under various loading. For any cellular
materials, energy absorption is a crucial parameter as it prevents structures from potential
impacts. Auxetic materials that contract laterally will yield more material in the middle part of
the structure, which could improve the energy absorption capability of it. However, the energy
absorption aspect of the auxetic structures is still unexplored. In this work, a known auxetic
structure (3D re-entrant) was tested under dynamic compressive loading. A finite element (FE)
model developed in ABAQUS/Explicit was validated using the test results. The validated FE
model was used to study the influence of the geometrical parameters on the strength, energy
absorption, and Poisson’s ratio. Based on the understanding, a novel auxetic unit cell was
developed and tested it under compression (Quasi-static and dynamic) loading. Newly
developed unit cells exhibited better energy absorption. Another novel unit cell was designed
to exhibit similar properties in three - directions. A novel hybrid tube concept was proposed
which utilizes auxetic tube as outer tube and a conventional hollow tube as inner tube. Hybrid
tube showed better specific energy absorption than auxetic tube, conventional tube, and sum
of auxetic and conventional tube.