Emergence of seismic metamaterials: Current state and future perspectives

Abstract

Following the advent of electromagnetic metamaterials at the turn of the century, researchers working in other areas of wave physics have translated concepts of electromagnetic metamaterials to acoustics, elastodynamics, as well as to heat, mass and light diffusion processes. In elastodynamics, seismic metamaterials have emerged in the last decade for soft soils structured at the meter scale, and have been tested thanks to full-scale experiments on holey soils five years ago. Born in the soil, seismic metamaterials grow simultaneously on the field of tuned-resonators buried in the soil, around building's foundations or near the soil-structure's interface, and on the field of above-surface resonators. In this perspective article, we quickly recall some research advances made in all these types of seismic metamaterials and we further dress an inventory of which material parameters can be achieved and which cannot, notably from the effective medium theory perspective. We finally envision perspectives on future developments of large scale auxetic metamaterials for building's foundations, forests of trees for seismic protection and metamaterial-like transformed urbanism at the city scale.

Recent Advances in Non-Traditional Elastic Wave Manipulation by Macroscopic Artificial Structures

“…Recently, elastic cloaking has been extended to the seismic waves that propagate through the Earth. Seismic MTMs, one of the most important application in EMTMs, are starting with the use of PCs and metasurface [35][36][37][38][39][40][41][42].…”

“…If a synthetic substance has either negative ρ or negative K, then waves within that substance have an imaginary-valued velocity, so they attenuate rather than propagate or reflect. These novel characteristics of EMTMs lead to various applications such as passive vibration attenuation systems [18][19][20][21][22][23][24][25], active vibration attenuation systems [26][27][28][29], energy harvesters [30][31][32], energy dissipation systems [33,34], seismic barriers [35][36][37][38][39][40][41][42], viscoelastic systems [43,44], non-reciprocal elastic wave propagation systems [45][46][47], gyroscopic metamaterials [48,49] and elastic topological phononic crystals [50,51].…”

Sustainability of Vibration Mitigation Methods Using Meta-Materials/Structures along Railway Corridors Exposed to Adverse Weather Conditions

“…In this way, local resonances could be excited in the resonators when the frequency of propagating waves reaches the eigenfrequencies. The disturbance to the buildings caused by ground vibrations would be decreased due to local resonances [27]. Given that the mitigation mechanism of metamaterial resonators is not based on structural periodicity, the structural size of resonators would not be as large as the pile diameter in pile barriers discussed above in order to achieve low-frequency vibration abatements.…”

Role of nanophotonics in the birth of seismic megastructures

“…Let us first stress that the seismic megastructures we describe in this article have metric to hectometric size. Basically, one can identify three main types of seismic metamaterials after a decade of research [4].…”