Crashworthiness and energy absorption characteristics of low-altitude aircraft with honeycomb bottom structures

Abstract With the development of the low-altitude economy, challenges and opportunities are gradually emerging. In potential crash accidents, it is necessary to enhance the crashworthiness of low-altitude aircraft to ensure the safety of the occupants. This paper studies different types of honeycomb energy-absorbing structures located at the bottom of the fuselage. Two types of honeycombs, hexagonal honeycomb (HEX) and re-entrant honeycomb (REH), are selected to construct an integrated energy-absorbing structure to absorb the impact kinetic energy during a crash accident. The effects of cellular type, unit size and wall thickness on the deformation mode and specific energy absorption (SEA) were systematically investigated. The results indicate that REH exhibits more stable hierarchical folding and a higher SEA. Furthermore, the study identifies an optimal geometric configuration, characterised by a specific combination of cellular size and wall thickness, that achieves the most effective balance between lightweight requirements and energy-absorbing capabilities.