Wave propagation in tunable lightweight tensegrity metastructure

TL;DR

This paper introduces a lightweight, tunable tensegrity metastructure with unique wave attenuation properties, developed through theoretical modeling, design of bandgap mechanisms, and experimental validation for broadband vibration control.

Contribution

It presents a novel theoretical model and design approach for lightweight tensegrity metastructures with tunable wave attenuation capabilities, including experimental validation.

Findings

Broadband wave attenuation achieved in tensegrity metastructures.

Tunable stiffness and wave propagation control demonstrated.

Validation through frequency response tests confirms wave attenuation ability.

Abstract

In this paper, lightweight metastructures are designed consisting of prismatic tensegrity building blocks which have excellent strength-to-weight ratio and also enable unique compression-torsion coupling. A theoretical model with coupled axial-torsional stiffness matrix is first developed to study the band structures of the proposed lightweight metastructures. Unit cell designs based on both Bragg scattering and local resonance mechanism are investigated to generate bandgaps at desired frequency ranges. Broadband full-wave attenuation is found in the tensegrity metastructure with special opposite-chirality unit cells. Furthermore, tunable stiffness in the prismatic tensegrity structure is investigated and 'small-on-large' tunability in the tensegrity metastructure is achieved by harnessing the geometrically nonlinear deformation through an external control torque. Prestress adjustment for fine tuning of the band structure is also investigated. Finally, frequency response tests on finite metastructures are preformed to validate their wave attenuation ability as well as their wave propagation tunability. The proposed tensegrity metastructures could be very useful in various engineering applications where lightweight and tunable structures with broadband vibration suspension and wave attenuation ability are in high demand.