Finite element dynamic analysis of rotating orthotropic sandwich annular plates

The finite element dynamic analysis of rotating orthotropic sandwich annular plates with a viscoelastic central layer and two polar orthotropic laminated face layers are analysed in the present paper. The axisymmetric discrete layer annular element and Hamilton's principle are employed to derive the finite element equations of motion for a rotating sandwich plate including transverse shear effects. The viscoelastic material in the central layer is assumed to be incompressible, and the extensional and shear moduli are described by complex quantities. Complex-eigenvalued problems are then solved, and the modal frequencies and loss factors of the sandwich plate are extracted. The results of the symmetric and non-symmetric sandwich annular plates are both presented. The effects of outer radius to thickness ratio, orthotropic properties of face layers, the thickness of the viscoelastic central layer, and thickness of face layers on the natural frequencies and modal loss factors of sandwich annular plates are discussed. (C) 2003 Elsevier Ltd. All rights reserved.