Design and energy absorption characteristics of a novel honeycomb with embedded chiral structures

Honeycomb structure as a thin-walled structure has excellent mechanical properties. In this work, three types of novel embedded chiral honeycomb (ECH) structures are proposed based on a hybrid strategy and manufactured by using the additive manufacturing (AM) technique. Quasi-static uniaxial compression tests in lateral and diagonal loading are carried out. The loading-displacement curves and deformation modes of ECHs are recorded and analyzed. The numerical models are established and its simulation results are in good agreement with the experiments. The results show chiral units have a significant enhancement on macro mechanical properties. It is found that ECH4 has the best energy absorption characteristics (EA of 49.52 J, SEA of 1.55 J/g) in lateral loading and ECH3 has the best (EA of 62.25 J, SEA of 2.14 J/g) in diagonal loading. The deformation patterns of structures are also discussed. Moreover, the effects of geometric parameters on the mechanical responses of ECHs are analyzed, including the effects of the circular node radii and the wall thickness. The optimal interval of parameter design is finally determined. The findings from this study are helpful for a new topology optimization design for hexagonal honeycomb structures with enhanced mechanical properties.