Crashworthiness design of hexagonal tubes using self-similar inspired structures

In this paper, we focus on the design of multi-cell hexagonal tubes filled with self-similar inspired multi-cell tubes with a different layout. The effect of the hierarchy design, layout optimization and the number of self-similar inspired substructures were numerically investigated. The multi-criteria decision-making method (COPRAS) is used to evaluate crashworthiness. The results show that the self-similar inspired substructures filled in the edge middle of the multi-cell hexagonal tubes provide a higher crushing force and specific energy absorption than those filled in the corner of these multi-cell tubes for both 0th and 1st order multi-cell hexagonal tubes. The crushing force and the specific energy absorption increase with the hierarchy and the number of substructures. The max specific energy absorption of 2nd order multi-cell hexagonal tubes with two self-similar inspired substructures is 2.82 times higher than that of the 1st order multi-cell hexagonal tubes with one self-similar inspired substructure. It is found that the crashworthiness of these multi-cell tubes can be further enhanced by optimizing the cross-sectional topology. The current study provides a new approach to optimizing the crashworthiness of self-similar inspired structures for engineering applications. [Display omitted]