Gradient index lenses for flexural waves based on thickness variations

Copyright (2014) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics along with the following message: The following article appeared in Applied Physics Letters 105, (6) and may be found at http://dx.doi.org/10.1063/1.4893153. Authors own version of final article on e-print serversThis work presents a method for the realization of gradient index devices for flexural waves in thin plates. Unlike recent approaches based on phononic crystals, the present approach is based on the thickness-dependence of the dispersion relation of flexural waves, which is used to create gradient index devices by means of local variations of the plate's thickness. Numerical simulations of known circularly symmetrical gradient index lenses have been performed. These simulations have been done using the multilayer multiple scattering method and the results prove their broadband efficiency and omnidirectional properties. Finally, finite element simulations employing the full three-dimensional elasticity equations also support the validity of the designed approach. (c) 2014 AIP Publishing LLC.This work has been supported by the U.S. Office of Naval Research under Grant No. N000140910554.Climente Alarcón, A.; Torrent Martí, D.; Sánchez-Dehesa Moreno-Cid, J. (2014). Gradient index lenses for flexural waves based on thickness variations. Applied Physics Letters. 105(6). doi:10.1063/1.4893153S105