A new tunable elastic metamaterial structure for manipulating band gaps/wave propagation

Abstract

A one-dimensional mechanical lattice system with local resonators is proposed as an elastic metamaterial model, which shows negative mass and negative modulus under specific frequency ranges. The proposed representative units, consisting of accurately arranged rigid components, can generate controllable translational resonance and achieve negative mass and negative modulus by adjusting the local structural parameters. A shape memory polymer is adopted as a spring component, whose Young’s modulus is obviously affected by temperature, and the proposed metamaterials’ tunable ability is achieved by adjusting temperature. The effect of the shape memory polymer’s stiffness variation on the band gaps is investigated detailedly, and the special phenomenon of intersecting dispersion curves is discussed, which can be designed and controlled by adjusting temperature. The dispersion relationship of the continuum metamaterial model affected by temperature is obtained, which shows great tunable ability to manipulate wave propagation.

Gradient continuum model of nonlocal metamaterials with long-range interactions

“…As significant advances in engineering structures, metamaterials have attracted increasing attention for their applications in controlling wave propagation and vibration reduction [1][2][3]. Metamaterials are composed of artificial periodic structures that are designed to achieve novel physical properties, such as an effective negative mass [4][5][6], negative refraction [7,8] and topological effects [9,10]. Metamaterials have potential applications involving shock absorption [11][12][13], frequency filters [14][15][16], and energy harvesting [17,18].…”