Effect of Hierarchical Geometries Matching on the Crashworthiness of Honeycomb

Structural hierarchy has become a popular technique to improve the crashworthiness of engineering structures. A study is conducted to explore the interaction between hierarchical geometries and determine the optimum honeycomb configuration that improves crashworthiness. Nine distinct second‐order vertex‐based hierarchical honeycombs are constructed by iteratively replacing the vertices of a square‐based honeycomb with squares, circles, and octagons. Validated finite element models are then established to investigate the out‐of‐plane crashworthiness performance. Subsequently, the effect of the hierarchical geometry combinations and cell length ratios on the crashworthiness performance of the nine honeycombs is studied. The study showed that the second‐order hierarchical honeycomb exhibited superior crashworthiness performance under the same relative density compared to the regular and first‐order hierarchical square honeycombs. The study determined that the circle is a suitable matching geometry in the first‐ and second‐order hierarchies for improving the crashworthiness of a square‐based honeycomb. Using Complex Proportional Assessment, the Square‐Circle‐Circle ranked as the optimum structure for crashworthiness application.