Simplified finite element analysis of vibration of sandwich plate

The natural frequencies of the sandwich plate simplified as a isotropic plate based on the equivalence principle are computed by using Mindlin plate finite element. The bending and shear modifying coefficients are derived according to the distribution of the stress and strain of the sandwich plate along the direction of the plate thickness. The solution of the complex eigenvalue is avoided for the sandwich plate with a viscoelastic core. A simplified analysis method can be provided for the engineering application.