Tran-Van-Nhieu Michel, Maze Gérard, Décultot Dominique
Thales Research & Technology, Campus Polytechnique, 1 avenue Augustin Fresnel, 91767, Palaiseau, France.
Normandie université, Université Le Havre Normandie, LOMC UMR CNRS 6294, 75 rue Bellot, 76058, Le Havre, France.
J Acoust Soc Am. 2017 May;141(5):3091. doi: 10.1121/1.4982039.
Acoustic scattering from a finite plate reinforced by parallel ribs with arbitrary rib spacing is investigated by applying thin plate and beam theories. The modal component of the surface pressure is calculated by an asymptotic expression that is only valid for higher-order modes at high frequencies. An approximate expression is derived for the far field scattered pressure by inverting matrices the rank of which is equal to twice the number of ribs. When the ribs are regularly spaced, approximate analytical expressions are proposed to calculate Bragg and forward Bloch-Floquet waves scattering separately from backward Bloch-Floquet waves scattering. These solutions are useful to deal with scattering problems where flexural waves are strongly attenuated after reflection on the edges of the plate. Finally the relevancy of the approximate expressions is evaluated by comparing numerical simulations to experimental data.
