Vibration and Damping Analysis of Laminated Plates with Fully and Partially Covered Damping Layers

The finite element method based on layerwise displacement theory is applied to the dynamic problem of anisotropic laminated plates treated with a constrained viscoelastic layer. Damping value of each mode is obtained by using the modal strain energy method and the modal approach to complex stiffness. To suppress the undesired vibrations of the wing skin in aircraft structures, the surface of the composite plates can be either fully or partially coated with a constrained viscoelastic layer. Through several numerical examples, the effects of stacking sequences, side-to-thickness ratios of the plate, locations of partially covered damping layers, and the thicknesses of the viscoelastic layers on vibration and damping characteristics are investigated.