弹性波超材料板中拓扑交界态与缺陷保护的主动控制研究

在波动周期结构中，六边形单胞是常见的具有动态拓扑性质的重复单元。本文设计了具有主动控制特性的六边形单胞，通过粘贴压电片并连接负电容电路对材料参数进行调控，实现了弯曲波拓扑交界态传输与缺陷保护特性的主动控制，并发现了该保护行为具有方向选择特性。上述工作将物理学与声学中拓扑态概念引入到弹性波超材料板中，从而实现了其中弯曲波拓扑传输的主动控制功能。

ACTIVE CONTROL ON INTERFACE STATE AND DEFECT PROTECTION OF ELASTIC WAVE METAMATERIALS

It is found that the hexagonal cell is a common repeating unit with dynamical topological properties in the wave periodic structure. In this work, a hexagonal cell is designed with active control properties. Piezoelectric patches are attached to unit cells and negative capacitance circuits are connected to regulate material parameters. Then, the active control on topological interface transmission and defect protection are achieved. Moreover, the defect protection depends on the structure direction. This investigation introduces the topological concepts of physics and acoustics into the elastic wave metamaterial plate, which can obtain the topological properties and actively controllable characteristics of flexural waves.