Vibration of nonhomogeneous orthotropic elliptic and circular plates with variable thickness

In this paper study of nonhomogeneity as well as variable thickness in elliptic and circular orthotropic plates is undertaken. Non-homogeneity of plate material is assumed to be a quadratic variation of Young's modulii and density whereas shear modulus, is considered to vary linearly along both the axes. The quadratic thickness variation in orthotropic nonhomogeneous plates is also considered. Effect of variation of these parameters on vibrational characteristics are analyzed for various boundary conditions at the edges. Results are obtained using boundary characteristic orthogonal polynomials generated by using Gram-Schmidt orthogonalization procedure in Rayleigh-Ritz method.