Effect of hierarchical structure on the shape recovery properties and load-carrying capacity of 4D-printed kirigami-inspired honeycomb

Kirigami-inspired honeycomb structures demonstrate outstanding self-expanding capabilities and exceptional mechanical properties. To further enhance the shape recovery properties and load-carrying capacity of kirigami-inspired honeycomb, the hierarchical structure is introduced by importing porous structures into cell walls of 4D-printed kirigami-inspired honeycomb (Structure II), and then an innovative honeycomb structure (Structure I) is designed for achieving the hierarchical effect. Additionally, three hierarchical structures with different shape configurations (Structure III–V) are also designed for comparing with traditional Structure II. The finite element analysis and experiments are conducted to compare the compression deformation behavior and energy absorption capacity of Structure I–V. It is found that Structure I exhibits significantly improved properties compared with the traditional Structure II. The stiffness of Structure I is increased by 50.43%, and the energy absorption performance is also increased by 65.00%. The recovery time has been shortened by 27.27% and it has a better shape recovery rate. Structure III–V can also enhance the performances compared with traditional Structure II. Structure IV exhibits the best energy absorption capacity, with an increase of 76.25%. Thus, the developed hierarchical kirigami-inspired honeycombs have broad application prospects for the multifunctional applications of honeycomb structures in the future.