Modal damping prediction of sandwich panel with visco-elastic thick core

Abstract

Free vibration and damping characteristics of a sandwich plate with elastic facings and visco-elastic core have been studied using a finite-element method. The present method considers a linear variation in the in-plane displacement through the thickness in the faces and a quadratic variation in the core. Quadrilateral finite elements were developed and a dynamic equation was derived. Damping has been introduced by considering a complex shear model of the visco-elastic material, which accounts for the phase difference between strain and stress. Eigenvalue problems are then solved, and the natural frequencies and modal loss factors of the sandwich plate are extracted. Effects of geometrical and material property parameters are discussed.