An insight from nature: honeycomb pattern in advanced structural design for impact energy absorption

The ability of a vehicle to protect its occupants from serious injuries in the event of a collision is defined as crashworthiness. The proper design of lightweight energy absorption components is a topic of interest because it can enhance the occupant's safety and lead to less fuel consumption and gas emission. Honeycomb structures are known to have excellent mechanical performances, which are mainly due to the configurations of the unit cell. Thus, they have attracted attention in the field of automobiles, railway vehicles, etc. In the present work, the criteria of crashworthiness as well as the nature-bioinspired cellular structures are first introduced. Then, the various classifications of advanced honeycomb design, including graded, hierarchical, and sandwich panel-based honeycomb structures, are established and discussed with a focus on the advantageous effect of various designs on the crashworthiness of honeycomb-based structures. Finally, the importance of potential design to enhance the crashworthy performance of honeycomb structures together with the future challenges is summarized. This work provides a good understanding of architectural design for a new generation of advanced honeycomb-based structures with efficient energy-absorbing properties.