Vibration and damping analysis of cylindrical sandwich panels containing a viscoelastic flexible core

In the present study, vibration and damping analysis of cylindrical sandwich panels containing a viscoelastic flexible core based on the high-order theory of sandwich structures is investigated. A layerwise formulation is developed to study the applicability of the high-order theory. The face sheets are considered as composite laminates with cross-ply layup that follow first-order shear deformation assumption and the core is considered as a linear viscoelastic medium with out-of-plane stresses only. The field equations along with the boundary conditions are derived via the application of Hamilton's principle. A closed-form solution is developed for simply supported boundary conditions and a comparison is made with available results in the literature to verify the high-order and layerwise solution results. Finally, the influence of parameters including the core stiffness, the core to the face sheets thickness ratio, and the core damping on the applicability of the high-order theory, and variation of natural frequencies and modal loss factors of the sandwich panel are investigated. The results demonstrate a good agreement between the high-order and layerwise theories for small core stiffnesses, and for a wide range of the core to the face sheet thickness ratio and core damping.