# Crashworthiness Design of Bidirectional Pyramidal Energy-Absorbing Tubes Based on Centipede Structures

## TL;DR

This paper designs energy-absorbing structures inspired by centipede movement to improve crashworthiness in engineering applications.

## Contribution

A novel biomimetic bidirectional pyramid energy-absorbing structure is proposed and optimized for enhanced performance.

## Key findings

- Foam-filled bidirectional pyramids show optimal energy absorption and stability.
- Optimal performance occurs within specific geometric parameter ranges.
- Multi-objective optimization reduces peak crushing force and increases energy absorption.

## Abstract

Energy-absorbing components should be effective and stable in engineering protective structure designs to reduce collision impacts. However, conventional energy-absorbing structures have considerable potential for optimization for energy dissipation and structural stability. Like other invertebrates, the centipede’s folding mode when moving forward is compatible with the hierarchical folding process when the energy-absorbing structure is impacted; however, this rule has not been thoroughly examined and proven. Based on this gap, this study built a unique biomimetic aluminum foam-filled bidirectional pyramid energy-absorbing structure, analyzed its geometric parameters on crashworthiness, and developed high-performance energy-absorbing components. Experiments and simulations were conducted on a bidirectional pyramid construction with three schemes for filling aluminum foam inspired by the centipede body section and profile. The construction with foam aluminum filling the gap has optimum specific energy absorption and load stability. Additionally, optimizing structural performance is most effective in certain ranges (78° ≤ θ ≤ 87°, t ≤ 0.1 mm, 34 mm ≤ d ≤ 44 mm). With Kriging and NSGA-III multi-objective optimization, the optimized peak crushing force decreases by 11.17% and specific energy absorption increases by 11.67%. The study and optimization process offers a theoretical reference for future high-performance energy-absorbing structures and has significant engineering application potential.