多稳态力学超材料带隙特性及调控研究

Multi-Stable Mechanical Mematerials for Band Gap Tuning

多稳态力学超材料具有多重稳定状态和几何重构特性,在变形吸能和能带调控等方面有重要的研究价值.本研究提出了一种多稳态力学超材料.该超材料是由具有双稳态特性的曲杆和相关实体支撑结构组成.结合有限单元法和布洛赫定理,计算了结构的能带结构,分析了不同稳态条件下结构的带隙特性,得到了几何参数对结构带隙的影响规律,并研究了由5×5个单胞组成的阵列结构中部分单胞变形时,整体结构的传输率.研究发现,双稳态连杆的变形状态可显著改变结构的带隙,尤其是在低频范围内产生了更宽的带隙.整体结构中局部一行或一列单胞变形即可在该方向对应带隙频率范围内实现弹性波传播的衰减.

The multi-stable mechanical metamaterials have the multiple stable status and geometric reconstruction characteristics,which are of great research value in deformation energy absorption and tuning of the band gap.In this study,a multi-stable mechanical metamaterial is proposed,which is composed of bistable curved rods and related solid support structures.Combining the finite element method and Bloch’s theorem,the band structure of the structure is calculated,the band gap characteristics of the structure with different steady-states are analyzed,the effects of geometric parameters on the band gap are obtained,and the transmissions of the array composed of 5×5 unit cells are studied when part of the cells are deformed.It is found that the deformation status of the bistable connecting rod can significantly change the band gap of the structure,especially in the low-frequency range.The elastic wave propagation can be attenuated within the corresponding band gap frequency range by deformation of a row of cells in the structure.