Harmonic Viscoelastic Waves Propagating Parallel to the Layers of Laminated Media

Abstract

The propagation of harmonic viscoelastic waves in laminated media is analyzed. The frequency equations are formulated for various wave modes propagating in the direction parallel to the layers of viscoelastic laminated media. The frequency-complex wave number spectra are obtained for the waves in an alternate laminated composite which consists of elastic reinforcing layers and viscoelastic matrix layers. And the phase velocity and the attenuation on the lowest branch are investigated in the range of low frequencies. It is found that the phase velocity of a viscoelastic wave propagating parallel to the layers is influenced by the shear wave velocity in the reinforcing material, by the longitudinal wave velocity in the plate made of the reinforcing material, or by the shear wave velocity in the matrix material. The wave attenuation also related with the above influences.