title: Experimental and numerical study of evanescent waves in the mini stopband of a 1D phononic crystal.
abstract: This paper deals with the analysis of the guided evanescent waves in stopbands of a 1D phononic crystal (PC). A new numerical implementation is shown in order to get the complex values of the wavenumbers in a frequency range where a gap occurs. The considered phononic system is an aluminum plate with a one-dimensional sinusoidal grating. For this structure a mode-gap (mini stopband) occurs at low frequency: it involves the two fundamental Lamb modes A(0) and S(0). The numerical study is performed by using a finite element method (ATILA code). The experiments deal with a finite length grating and evanescent waves are characterized at the vicinity of the mini stopband.
authors.affiliation: ENI Val de Loire, Groupement de Recherche Matériaux Microélectronique Acoustique Nanotechnologies, UMR CNRS 7347, 41034 Blois, France. maxime.bavencoffe@univ-tours.fr
authors.forename: Maxime
authors.initials: M
authors.lastname: Bavencoffe
authors.forename: Bruno
authors.initials: B
authors.lastname: Morvan
authors.forename: Anne-Christine
authors.initials: AC
authors.lastname: Hladky-Hennion
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Izbicki