Free vibration analysis of sandwich panel plate with FML face sheet and flexible core using third-order shear deformation theory

This paper investigates the free vibrations of a sandwich panel with metal/composite hybrid face sheets reinforced with carbon and glass fibers and a soft core with simply-support boundary conditions. To derive the governing equations, with third shear deformation theory (TSDT) of multilayers and Hamilton's principle have been used for a rectangular sandwich panel with a metal/composite hybrid top and bottom face sheets. It is assumed full connection of the face sheets to the softcore and linear displacement. After comparing the results of the present research with similar and ensuring the correctness of the extracted equations, the parameters effective, volume fraction metal layer and composite with angular layering, the ratio of length to thickness and thickness of the core to the face sheet, length sandwich panel to width and the layup (0,90) and (45, -45) for two types of glass and carbon fibers hybridized with AL 2024 T3 aluminium investigated. The results showed that the carbon/aluminium hybrid with the volume of the composite (Vc) equal to 0.5 has the highest natural frequency value in the first five mode shapes with layup AL/-45/45/core/45/-45/AL. Also, by increasing the thickness of the softcore to the surface and the ratio of length sandwich panel to total thickness, the effect of the aluminium layer decreases.