Mechanical Behavior of Hexagonal Tubes Reinforced with Circular Inner Ribs under Axial Load

Inspired by the gradient layered structure of bamboo, a series of hexagonal hierarchical multicellular tubes (HHMT) with circular reinforcement are proposed. This design integrates circular reinforcement into traditional hexagonal tubes and applies a hierarchical concept to enhance structural performance. A finite element model of the structure is developed using Abaqus/Explicit, and the crashworthiness of the HHMT with a hierarchical structure is systematically investigated. The results indicate that higher‐order HHMTs exhibit superior energy absorption capacity and impact force efficiency compared to lower‐order configurations under both identical thickness and mass conditions. Notably, the B‐structure of 3rd‐order HHMT (HHMT‐3B) demonstrates energy absorption rates that are 23.30 times greater than those of the conventional hexagonal tube under the same wall thickness conditions, with a significantly faster increase in the initial peak force. The findings suggest that augmenting the thickness of the second‐order circular reinforcing ribs effectively enhances the crashworthiness of the structure, particularly in terms of energy absorption capacity per unit mass and load stability, as compared to 3rd‐order HHMT with the same wall thickness. Finally, a comparative analysis with other multicellular tubes is conducted to illustrate the superiority of the proposed hexagonal layered multicellular tube with circular reinforcing ribs.