Effect of Criterion Dependence on the Selection of Biomimetic Crash Boxes: A Multi-Method and Stochastic Evaluation

In nature-inspired thin-walled energy absorbers, the biological prototype is increasingly selected with multi-criteria decision-making (MCDM) tools, yet the effect of algebraic dependence among criteria on this selection is rarely examined. Nine biomimetic sections within a common envelope (Ø60 × 120 mm, t = 1.2 mm) are investigated under axial crushing through finite element modeling validated against published experimental data. Peak crushing force, specific energy absorption, and crush force efficiency, the triplet most often combined in studies with verified numerical weights, form the primary set; 48 combinations of six weighting schemes and eight ranking methods, and a separate SMAA-2 analysis per method, are applied. Only three sections are Pareto non-dominated; the beetle forewing-inspired section ranks first in 31 of 48 runs and the daisy-inspired section in 17, but the latter leads in 39 runs with a folding trigger. Adding mean crushing force, as in two published criterion sets, raises the spider web-inspired section to first place in 26–32 runs, also under ratio-preserving weights. This shift persists with triggers and propagated value uncertainty; adding the mesh-sensitive undulation of load-carrying capacity mainly strengthens the daisy-inspired section. Biomimetic design selection thus depends as much on how performance is represented as on performance itself.