Three-dimensional free vibration of laminated cylindrical panels with functionally graded layers

The three-dimensional (3D) free vibration of laminated cylindrical panels with finite length and functionally graded (FG) layers is presented. The cylindrical panels with two opposite axial edges simply supported and arbitrary boundary conditions at the curved edges can be analyzed via the present approach. The material properties vary continuously through the layers thickness. In order to accurately model the variation of the displacement components through the panel thickness, a layerwise-differential quadrature method (LW-DQM) is employed in this direction. Also, the in-plane variations of the displacement components are approximated using the trigonometric series in the circumferential direction and the DQM in the axial direction. The fast rate of convergence and accuracy of the method are demonstrated through different examples. As applications of the present approach, the free vibration of two common types of sandwich cylindrical panels, i.e. sandwich panels with FG face sheets and ceramic core and sandwich panels with FG core and ceramic/metal face sheets, and also bi-layered FG cylindrical panels are studied. The effects of geometrical and material parameters together with the boundary conditions on the frequency parameters of these types of panels are investigated.