Double-layer helix honeycomb structure with optimal torsion angle achieving excellent compressive performances

A double-layer helix honeycomb (DLHH) is designed and manufactured using FFF additive manufacturing technology. Equivalent to introducing chiral structures into the honeycomb structure, the final structural configuration is similar to that of origami honeycomb. The in-plane and out-of-plane mechanical properties of DLHH with different torsion angles and relative densities are studied through a combination of experiments and simulations. The results indicate that with the increase of torsion angle, the compression resistance and energy absorption capacity of the structure in the plane are effectively improved. However, the out-of-plane performance of DLHH decreases to varying degrees with an increase in torsion angle. In addition, it's found that the out-of-plane performance of DLHH with a 30° torsion angle is similar to that of TH, while its in plane performance is twice that of TH. The experimental and simulation results indicate that the deformation mode of DLHH during in-plane compression is affected by the torsion angle. When the torsion angle is 60°, there is a stable approximate horizontal layer by layer deformation mode, while TH and other angles of DLHH exhibit shear deformation mode. These findings open a new path for designing single-layer thin-walled honeycomb structures and lay the foundation for the design of lightweight protective structures.