Flexural Vibrations of an Elastic Plate With Two Symmetric Viscoelastic Coatings

Abstract

The flexural-vibration characteristics of a symmetric, doubly infinite composite plate consisting of two outer layers of a linear viscoelastic material bonded to an elastic core have been examined, the viscous effects in the coating being represented by a complex shear modulus. Calculations of the dispersive and damping effects have been obtained for the lowest three modes by an extension of the exact Rayleigh-Lamb equations. Loss factors of the lowest modes have also been evaluated by two readily computed approximate methods; the results have been compared with those from the exact solution. The material constants were chosen to be representative of a high-polymer coating and an aluminum core. The modal behavior of the systems and coupling effects are discussed.