free vibration analysisof soft-core composite-faced sandwich plates using three-dimensional finite element method

in this paper, natural frequencies of the sandwich plates with soft flexible core and composite face sheets are obtained. three-dimensional (3d) finite element method (fem) is used for constructing and analyzing of the sandwich plates to obtain their natural frequencies. continuity conditions for transverse shear stresses at the interfaces as well as transverse flexibility and transverse normal strain and stress of the core are considered.the effects of plate dimensions such as aspect ratio and thickness ratio are studied. also, different boundary conditions such as all edges clamped (cccc), all edges simply supported (ssss) and combined boundary conditions including (cfcf)are applied to the sandwich plates. comparison of the present results in special case with those of the accurate plate theories confirms the accuracy of the proposedmodel.