Synchronous enhancement of extreme-damping and stiffness in elastic mechanical metamaterials via self-tensioning friction mechanism

Abstract

Reusable mechanical metamaterials with both high energy-dissipating and load-bearing features are ideal candidates for widespread dynamic applications, ranging from impact mitigation to vibration suppression. Despite great demands, the existing designs either exhibit limited damping or stiffness, and perhaps work well only for one-time use. To reconcile these contradictions, a synchronous enhancements strategy of damping and stiffness is proposed to create novel mechanical metamaterial by replacing the viscous damping in the viscoelastic material Kelvin-Voigt constitutive to frictional damping, exemplified by auxetic self-tensioning friction damping metamaterials (FDM). They trigger an embedded sliding friction behavior through auxetic effect to achieve energy dissipation, which especially shows high stiffness while achieving extreme damping ability synergistically under large compressive strain. This synchronous enhancement mechanism is analysed by combining finite element modelling, theoretical analysis, and experimental validation. These innovative mechanical metamaterials with repeatability and self-recoverability have broad applications in engineering materials-structures-systems for energy-dissipation and load-carrying.