In this project I designed and developed large scale elastodynamic metamaterial devices based on subwavelength elements to mitigate the damage created by surface (Rayleigh) and bulk (coupled shear and pressure) solid mechanics waves due to any type of vibration in structural components or earthquakes. I took advantage of the internationally renowned modelling skills of the applied mathematics group of Prof. Richard Craster at Imperial College, as well as ideas of negative refraction and cloaking that have been initiated and developed by Sir John Pendry at the Physics Department of Imperial College at the turn of this century. So-called electromagnetic metamaterials are becoming well established in the wave physics community of optics and electromagnetism, but their elastodynamic counterparts are less well studied. Transferring the knowledge of electromagnetic metamaterials to large scale elastodynamic metamaterials, also known as seismic metamaterials, draw upon my experience in mechanical and civil engineering. Recent developments in photonic topological insulators, which are the electromagnetic wave counterparts of electronic topological insulators (metal insulators whose surface contains conducting states, that is electrons can only move along their surface), have been at the core of my research for the last year of my fellowship, with the design and numerical validation of the first topological seismic rainbow in an elastic plate of varying thickness with judiciously patterned square perforations. This novel device has great potential in energy harvesting, and can be considered the main theoretical achievement of my research project. However, thanks to the participation of Institut Fresnel in this project, and the collaboration with the team of Stéphane Brûlé at the Menard civil engineering company in Lyon, I have been able to conduct the first in-situ experiments for Rayleigh waves propagating within a doubly periodic array of ancient stones (known as menhirs) in Carnac, France.
