Interaction of lamb modes with delaminations in plates coated by highly absorbing materials.
A theoretical study of Lamb mode propagation through an absorptive bilayer consisting of a steel plate coated by highly absorptive rubber with a finite delamination dividing these layers is presented. Essentially, in such a bilayer structure, steel-like A0 and S0 modes still propagate, although with moderate absorption. Two different types of delaminations are taken into consideration: slip delaminations in which noncontact boundary conditions are assumed only for shear displacement and stress, and stress-free delaminations in which noncontact boundary conditions are assumed for all mechanical displacements and stresses. The calculations, which are based on a modal decomposition method, show that delaminations in absorptive bilayers result in a considerable change of the normal displacement amplitude at the bilayer surfaces inside the delamination region, and for an incident mode steel-like A0 mode, also in the transmission region. Stress-free and slip delaminations can be distinguished exploiting their different effect on the steel-like A0 and S0 incident modes.
Shkerdin
Gennady
G
Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Vvedensky sq., 1, Fryazino, Moscow region, Russia.
Glorieux
Christ
C
D000042:Absorption; D000162:Acoustics; D003198:Computer Simulation; D008420:Manufactured Materials; D008422:Materials Testing; D008956:Models, Chemical; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods; D012408:Rubber / Q000737:chemistry*; D013232:Steel / Q000737:chemistry*; D014732:Vibration
D013232:Steel; D012408:Rubber