Adaptive Twisting Metamaterials.

Area of Science:

• Materials Science
• Mechanical Engineering
• Metamaterials

Background:

• Next-generation protective systems need materials that adapt to impact severity.
• Existing materials often have fixed responses, limiting protection effectiveness.
• Adaptive materials offer multiple force-displacement pathways for tailored impact response.

Purpose of the Study:

• Introduce twisting metamaterials as a novel class of adaptive architected lattices.
• Investigate the mechanics and adaptive crashworthiness of these structures.
• Demonstrate a multiscale predictive framework for their design and application.

Main Methods:

• Utilized micropolar elasticity to model the mechanics of twisting metamaterials.
• Employed a multiscale predictive framework combining Cosserat continuum mechanics, finite element modeling, and experimental validation.
• Additively manufactured and tested twisting gyroid structures under quasi-static and dynamic compression with varying torsional constraints.

Main Results:

• Twisting metamaterials exhibit geometry-induced torsional actuation and nonlinear responses.
• Constrained rotation leads to high axial stiffness (4.8 GPa), collapse stress (21 MPa), and specific energy absorption (15.36 J/g).
• Free-to-twist and over-rotation conditions reduce performance by up to 33%, demonstrating adaptive energy absorption.

Conclusions:

• Twisting metamaterials offer tunable mechanical responses for adaptive crashworthiness.
• The developed multiscale framework accurately predicts performance and guides design.
• These materials show promise for advanced protection systems in automotive, aerospace, and defense applications.