Mechanical behavior of composited structure filled with tandem honeycombs

Recently, how to significantly improve the energy absorption property of honeycomb structures have drew a lot of attention. As a potential excellent way out, tandem honeycomb has sprang up and rapidly gained popularity. In the present work, comprehensive experiments of tandem hexagonal honeycomb structures subjected to axial compression has been conducted with general, strength gradient, and pre-compressed specimens, respectively. Extensive mechanical behaviors of kinds of tandem honeycomb structures have been demonstrated. Although highly random deformation sequences were observed in those specimens, the tandem honeycomb structure still performed as perfect response as in the general pieces of honeycomb block under compression load. In addition, the tandem honeycomb structure performed a better mechanical behavior and showed a stable, rectangular-like compression history after pre-compression, no initial peak force appeared for subsequent segments. Based on this, numerical simulations for tandem honeycomb-filled energy absorber were conducted using homogenized constitutive model which was validated by experiments. Two typical conformation modes, lateral reinforced structure and multi-cell structure were discussed through numerical analyses on matching effect and multi-cell effect. The results turned out that the lateral resistance has significant influence on deformation mode and filling tandem honeycomb into multi-cell tubes evidently improves the mechanical behavior of such structures. All the achievements shed a light on the design of impact energy absorbers which consisted of composited honeycomb cores.