FREE-VIBRATION OF POLAR ORTHOTROPIC LAMINATED CIRCULAR AND ANNULAR PLATES

The paper deals with the free vibration analysis of polar orthotropic laminated circular and annular plates. The first order shear deformati on theory and the variational energy method are employed in the mathem atical formulation, and an eight-node isoparametric finite element mod el in polar co-ordinates is used for finding natural frequencies. The effects of material property, stacking sequence, hole size, plate thic kness to radius ratio and boundary conditions on natural frequencies a re investigated. Numerical results are shown in tabular and graphical forms, and some comparisons with existing results are made for the val idation purpose. (C) 1998 Academic Press Limited.