Active control on topological immunity of elastic wave metamaterials

Guan-Hua Li,Yue-Sheng Wang,Tian-Xue Ma,Yi-Ze Wang

doi:10.1038/s41598-020-66269-2

Guan-Hua Li, Yue-Sheng Wang + Show 2 more

Open Access

https://doi.org/10.1038/s41598-020-66269-2

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Abstract

The topology concept in the condensed physics and acoustics is introduced into the elastic wave metamaterial plate, which can show the topological property of the flexural wave. The elastic wave metamaterial plate consists of the hexagonal array which is connected by the piezoelectric shunting circuits. The Dirac point is found by adjusting the size of the unit cell and numerical simulations are illustrated to show the topological immunity. Then the closing and breaking of the Dirac point can be generated by the negative capacitance circuits. These investigations denote that the topological immunity can be achieved for flexural wave in mechanical metamaterial plate. The experiments with the active control action are finally carried out to support the numerical design.

Highlights

The topology concept in the condensed physics and acoustics is introduced into the elastic wave metamaterial plate, which can show the topological property of the flexural wave
We focus on elastic wave metamaterials with double Dirac points locating at the center of the Brillouin zone
When the negative capacitance circuits are not connected, the band structure calculated by the finite element method is shown in Fig. 2(a) and we can see that the band gap width is about 35 Hz

Summary

Introduction

The topology concept in the condensed physics and acoustics is introduced into the elastic wave metamaterial plate, which can show the topological property of the flexural wave. The closing and breaking of the Dirac point can be generated by the negative capacitance circuits These investigations denote that the topological immunity can be achieved for flexural wave in mechanical metamaterial plate. Phononic crystals and elastic wave metamaterials are artificial structures which are arranged periodically and have received lots of attention[1,2,3,4,5,6,7,8] These new kinds of structures have many extraordinary properties, e.g. the wave band gaps[9,10,11,12], negative refraction[13,14], acoustic/elastic wave cloaks[15,16,17], etc. Based on the electrical control action, the Dirac point and its corresponding topological immunity can be achieved

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Results

Conclusion