Research Article

Auxetic-like metamaterials as novel earthquake protections

¹ Faculty of Civil Engineering and Building Services Technical University “Gheorghe Asachi” of Iasi, 43, Dimitrie Mangeron Blvd., 700050 Iasi, Romania
² Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR7249, 13013 Marseille, France
³ Dynamic Soil Laboratory, Ménard, 91620 Nozay, France

^* e-mail: sebastien.guenneau@fresnel.fr

Received: 15 September 2015
Accepted: 31 December 2015
Published online: 26 February 2016

Abstract

We propose that wave propagation through a class of mechanical metamaterials opens unprecedented avenues in seismic wave protection based on spectral properties of auxetic-like metamaterials. The elastic parameters of these metamaterials like the bulk and shear moduli, the mass density, and even the Poisson ratio, can exhibit negative values in elastic stop bands. We show here that the propagation of seismic waves with frequencies ranging from 1 Hz to 40 Hz can be influenced by a decameter scale version of auxetic-like metamaterials buried in the soil, with the combined effects of impedance mismatch, local resonances and Bragg stop bands. More precisely, we numerically examine and illustrate the markedly different behaviors between the propagation of seismic waves through a homogeneous isotropic elastic medium (concrete) and an auxetic-like metamaterial plate consisting of 4³ cells (40 m × 40 m × 40 m), utilized here as a foundation of a building one would like to protect from seismic site effects. This novel class of seismic metamaterials opens band gaps at frequencies compatible with seismic waves when they are designed appropriately, what makes them interesting candidates for seismic isolation structures.