The aim of this study is to investigate the wave propagation characteristics of one-dimensional inertial amplification (IA) metamaterials with double resonators. The IA Angle is introduced by the IA mechanism as a critical parameter to modulate elastic waves. Double attenuation peaks in the bandgaps caused by coupling the IA mechanism and local resonance can be created in different ranges by adjusting the IA Angle. Moreover, a novel phenomenon of negative relative group velocity is observed in the region of double-negative effective properties, denoting negative energy flow. Numerical simulations using Gaussian pulse excitation are performed to validate the existence of a backward wave corresponding to the negative relative group velocity in the time domain. Furthermore, bandgap merging occurs in the region of double-zero effective properties, resulting in broadband wave attenuation. In particular, instead of using traditional metamaterials, two local resonator bandgaps can be merged to expand the bandgap range by at least 30% without changing the unit cell mass. The research results can be used to tune wave propagation in metamaterials, providing ideas for metamaterial design.

本研究的目的是研究具有双谐振器的一维惯性放大 (IA) 超材料的波传播特性。IA 角度由 IA 机制引入，作为调制弹性波的关键参数。通过调整 IA 角度，可以在不同范围内创建由耦合 IA 机制和局部共振引起的带隙中的双衰减峰。此外，在双负有效特性区域观察到负相对群速度的新现象，表示负能量流。执行使用高斯脉冲激励的数值模拟以验证与时域中的负相对群速度相对应的反向波的存在。此外，带隙合并发生在双零有效特性区域，导致宽带波衰减。特别是，不使用传统的超材料，而是可以合并两个局部谐振器带隙，以在不改变晶胞质量的情况下将带隙范围扩大至少 30%。研究成果可用于调谐波在超材料中的传播，为超材料设计提供思路。