Bionic Inner-Tapered Energy Absorption Tube Featuring Progressively Enhanced Fold Deformation Mode

Area of Science:

• Materials Science
• Mechanical Engineering
• Biomechanics

Background:

• Slender tubes are vital for lightweight structures but susceptible to buckling under axial load.
• Growing bamboos exhibit superior energy absorption due to their unique tapered internal structure.
• Conventional slender tubes lack efficient energy dissipation mechanisms, leading to catastrophic failure.

Purpose of the Study:

• To design and evaluate a bionic inner-tapered tube (BITT) inspired by bamboo for enhanced axial energy absorption.
• To analyze the energy absorption mechanisms of the BITT under axial compression.
• To explore the effects of geometric parameters on the energy absorption performance of BITT and its array structures.

Main Methods:

• Quasi-static axial compression testing to evaluate special energy absorption (SEA).
• Theoretical calculations and finite element analysis (FEA) to understand deformation modes and energy absorption mechanisms.
• Fabrication and testing of bionic square array (BSA) and bionic hexagon array (BHA) structures.

Main Results:

• The BITT's tapered inner wall promotes progressive folding deformation, preventing buckling and reducing initial peak load.
• BITT demonstrates significantly improved energy absorption efficiency due to increased plastic deformation compared to conventional tubes.
• The study explored the influence of taper angle and length-diameter ratio on BITT's energy absorption capabilities.
• Bionic arrays (BSA and BHA) based on BITT showed enhanced overall energy absorption performance.

Conclusions:

• The bionic inner-tapered tube (BITT) effectively enhances energy absorption and prevents buckling failure in slender tubes.
• The tapered internal structure is key to improved energy dissipation through controlled folding deformation.
• BITT serves as a promising structural unit for developing advanced energy-absorbing materials and structures.