Vibration of a three-layered ring on periodic radial supports

Abstract

The natural frequencies of a three-layered elastic ring on periodic radial supports are obtained by using a wave approach. Two types of support conditions are investigated. When the core is assumed to be viscoelastic, the theory of forced damped normal modes is used to obtain the resonance frequencies and the associated composite modal loss factors of the damped structure. The numerical results show the effects of the thickness ratios and the core shear modulus. The high values of the loss factor in some modes are explained with the aid of the mode shapes of the corresponding elastic ring.