Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2006.1591.1595HsuMing-Hung7200667The eigenvalue problems of annular plates are numerically formulated using the modified generalized differential quadrature method. The modified generalized differential quadrature method does not use the δ method. Appropriate boundary conditions accompany the modified generalized differential quadrature method to transform the partial differential equations of annular plates into discrete eigenvalue problems. Numerical results indicated that the accuracy of the calculated results is improved significantly by employing the modified generalized differential quadrature method. The effect of grid point number and the values of δ on the accuracy variation of calculated natural frequencies are also discussed.]]>Azimi, S., 1988Azimi, S., 1988Bellman, R. and J. Casti,1971Bellman, R.E., B.G. Kashef and J. Casti, 1972Bert, C.W. and M. Malik,1996Chen, W. and T. Zhong, 1997Civan, F., 1994Hua, L. and K.Y. Lam, 1998Malik, M. and C.W. Bert,1996Quan, J.R. and C.T. Chang,1989Quan, J.R. and C.T. Chang,1989Wang, X., J. Yang and J. Xiao,1995