A Tunable Metamaterial Joint for Mechanical Shock Applications Inspired by Carbon Nanotubes

The significant developments of additive manufacturing and especially 3D-printing technologies have broadened the application field of metamaterials. The present study aims at establishing the main design parameters of a novel 3D-printed polymer-based joint. The proposed joint can efficiently absorb impact energy, relieving the material components from extensive plastic deformations. The design of the machine element is inspired by the molecular structure of carbon nanotubes and appropriately adjusted in such a way that it has the ability to partially transform translational motion to rotational motion and, thus, provide axial structural protection from compressive shocks. The utilized material is a photosensitive resin that is typically utilized in 3D manufacturing processes. Experiments are utilized to characterize the mechanical performance of the raw material as well as the static compressive behavior of the joint. Finally, finite element simulations are performed to test the developed design under impact loadings characterized by different frequencies. The damping capabilities of the metamaterial-based joint are revealed and discussed.