FLOQUET ANALYSIS OF GUIDED-WAVES IN PERIODICALLY LAYERED COMPOSITES

In this paper analytical and numerical calculations, together with exp erimental measurements, are presented on the propagation of elastic gu ided waves in a composite plate composed of periodic layers. The guide d waves are constructed by superposing obliquely traveling Floquet par tial wave solutions in such a way that they satisfy a standing-wave re sonance condition through the thickness of the periodic composite. It is demonstrated that transverse resonance can be established only in t he Floquet passbands of the periodic composite. The predicted reflecti on spectra are compared with experimental observations in the Lamb wav e case for an aluminum/aramid-epoxy composite and demonstrate excellen t detailed agreement. This study offers an opportunity to gain new ins ight into the technologically important problem of plates with periodi c structures. (C) 1995 Acoustical Society of America.