Acoustics and Vibration Laboratory, School of Engineering, Indian Institute of Technology, Mandi, Himachal Pradesh, India.
Department of Mechanical Engineering, National Institute of Technology, Agartala, Tripura, 799046, India.
Sci Rep. 2023 Feb 9;13(1):2293. doi: 10.1038/s41598-023-27678-1.
Metamaterials are periodic structures made by repeating a unit cell. Such a structure shows frequency-specific wave attenuation behaviour. In this work, a 2D metamaterial foundation is proposed for the seismic protection of buildings. The paramount challenge is to offer low frequency attenuation (~ 2-8 Hz), which is the dominant excitation during an earthquake. Based on the parametric study performed, a new type of metamaterial structure was proposed. It was found that the foundation consisting of repeating circular scatterers made of steel and plumbum embedded in rubber matrix can provide low and wide frequency wave attenuation from 2.6 to 7.8 Hz. The computational model of the structure was subjected to transient excitation against three pre-recorded earthquake excitations. The result showed that the novel foundation can resist the propagation of the seismic wave to the structure. Further, the response of a 2D building frame with metamaterial foundation was compared to a concrete foundation exposed to different earthquake excitations. The results are very promising as the frame vibration on the metamaterial foundation was significantly less than the same frame on the concrete foundation. The presented work opens the path to new research and development of seismic metamaterial foundation for earthquake attenuation.
超材料是由重复单元胞构成的周期性结构。这种结构表现出频率特定的波衰减行为。在这项工作中，提出了一种二维超材料基础来保护建筑物免受地震影响。主要的挑战是提供低频衰减（~2-8 Hz），这是地震中主要的激励频率。基于进行的参数研究，提出了一种新型的超材料结构。结果发现，由嵌入橡胶基质中的钢和铅重复圆形散射体组成的基础可以提供从 2.6 到 7.8 Hz 的低频宽频波衰减。对结构的计算模型进行了瞬态激励，以模拟三种预先记录的地震激励。结果表明，新型基础可以抵抗地震波向结构的传播。此外，还比较了具有超材料基础的二维建筑框架与暴露于不同地震激励的混凝土基础的响应。结果非常有希望，因为超材料基础上的框架振动明显小于混凝土基础上的相同框架。这项工作为地震衰减的地震超材料基础的新研究和开发开辟了道路。
