title: Gradient Index Devices for the Full Control of Elastic Waves in Plates.
abstract: In this work, we present a method for the design of gradient index devices for elastic waves in plates. The method allows the design of devices to control the three fundamental modes, despite the fact that their dispersion relation is managed by different elastic constants. It is shown that by means of complex graded phononic crystals and thickness variations it is possible to independently design the three refractive indexes of these waves, allowing therefore their simultaneous control. The effective medium theory required for this purpose is presented, and the method is applied to the design of the Luneburg and Maxwell lenses as well as to the design of a flat gradient index lens. Finally, numerical simulations are used to demonstrate the performance of the method in a broadband frequency region.
authors.affiliation: School of Aerospace Engineering and Applied Mechanics, Tongji University, 100 Zhangwu Road, 200092, Shanghai, China.|Institut d'Electronique, de Micro électronique et de Nanotechnologie, UMR CNRS 8520, Université de Lille 1, 59655 Villeneuve d'Ascq, France.
authors.forename: Yabin
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Université de Bordeaux, Centre de Recherche Paul Pascal, UPR 8641, 115 Avenue Schweitzer, 33600 Pessac, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Torrent
authors.affiliation: Institut d'Electronique, de Micro électronique et de Nanotechnologie, UMR CNRS 8520, Université de Lille 1, 59655 Villeneuve d'Ascq, France.
authors.forename: Yan
authors.initials: Y
authors.lastname: Pennec
authors.affiliation: School of Aerospace Engineering and Applied Mechanics, Tongji University, 100 Zhangwu Road, 200092, Shanghai, China.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Institut d'Electronique, de Micro électronique et de Nanotechnologie, UMR CNRS 8520, Université de Lille 1, 59655 Villeneuve d'Ascq, France.
authors.forename: Bahram
authors.initials: B
authors.lastname: Djafari-Rouhani