WCCM V Fifth World Congress on Computational Mechanics July 7-12, 2002, Vienna, Austria Eds.: H.A. Mang, F.G. Rammerstorfer, J. Eberhardsteiner Transverse Vibration of Symmetrically Laminated Elastically Restrained Plates of Variable Thickness Ahmed S. Ashour International Islamic University Malaysia, Department of Science in Engineering, 53100 Kuala Lumpur, Malaysia e-mail: ashour@iiu.edu.my Key words: Finite strip method, vibration, symmetrically laminated, elastic restrained Abstract The natural frequencies of symmetrically laminated plates of variable thickness are analyzed using the finite strip transition matrix technique. In this paper, the natural frequencies of such plates are determined for edges with elastic restrained against rotation, transition or both. A successive conjunction of the classical finite strip method and the transition matrix method is applied to develop a new modification of the finite strip method to reduce the complexity of the problem. The displacement function is expressed as the product of a basic trigonometric series function in the longitudinal direction and an unknown function that has to be determined in the other direction. Using the new transition matrix, after necessary simplification and the satisfaction of the boundary conditions, yields a set of simultaneous equations that leads to the characteristic matrix of vibration. Numerical results for different combinations of elastic rotational or transitional edges have been presented and compared with those available from other methods in the literature. Also, the effect of the tapered ratio and the aspect ratio on the natural frequencies of the plates is presented. The good agreement with other methods demonstrates the validity and the reliability of the proposed method.