The Uniform Honeycomb-filled Tube (UHT) is one of the composite structures that has shown huge potential in absorbing energy. In this paper, Uniform Honeycomb (UH) filler is replaced by an enhanced Modularized Honeycomb (MH). The biggest advantage of MH is that it can significantly enhance energy absorption without adding weight compared with its uniform counterpart. Finite element models are created, and then validated by theoretical models. The energy absorption of the Modularized Honeycomb-filled Tube (MHT) is compared with that of the empty tube and UHT. The results show that the MHT is superior to them in Specific Energy Absorption (SEA). It is also found that the tube can help the MH improve its deformation stability, which is the key of the MHT’s excellent energy absorption capacity. Then, effects of design parameters on the SEA of the MHT are investigated and discussed. The results show that the MH with a large graded coefficient is good for enhancing the SEA of the MHT. However, the SEA also relies on the match between the honeycomb filler and tube walls. The work could inspire designs of modularized filler with various types of cells and benefit the development of advanced energy absorbers with lighter weight and more excellent energy absorption capacity.

Being adaptive with respect to changing operating conditions and the environment are imperative demands for advanced engineering structures. In this research, two Kresling origami units are stacked together to form an online and on-demand tunable Dual-Kresling Origami Structure (D-KOS), allowing easy and significant change of the multistability profile and apparent stiffness without redesign. Specifically, by harnessing its non-rigid folding nature together with geometric characteristics, D-KOS can be programmed to follow distinct paths of its strain energy contour as varying ϕp (rotational angle of the top plate of the D-KOS), which can be utilized to explicitly derive different mechanical properties. The D-KOS with identical Kresling origami units can exhibit various symmetric bistable behaviors with different energy barrier via adjusting ϕp. Such a structure becomes a monostable system as the tuning variable reaches a critical value. This change of the energy landscape and stability profile gives rise to the change of stiffness at its stable equilibria, which as a result creates a wide range of stiffness value one can achieve, including quasi-zero stiffness. Such tuning of ϕp does not require redesign of the structure, and thus can achieve online and on-demand tailoring. To verify the concept, proof-of-concept prototypes are developed and utilized to validate the D-KOS’s mechanical tunability experimentally. Moreover, different design parameters of D-KOS can change the tunability of D-KOS. For example, the D-KOS with non-identical Kresling origami units can possess even richer stability properties (being asymmetric bistable, symmetric bistable and monostable) with various energy landscapes. In addition, one can also tailor the range of the adjustable stiffness by changing the design parameters, such as ratio of the angle between polygon side and valley crease of the triangular facets, and the height of Kresling origami unit.