FREE VIBRATION OF ANNULAR ELLIPTIC PLATES USING BOUNDARY CHARACTERISTIC ORTHOGONAL POLYNOMIALS AS SHAPE FUNCTIONS IN THE RAYLEIGH–RITZ METHOD

Two-dimensional boundary characteristic orthogonal polynomials in the Rayleigh-Ritz method are used to obtain higher modes of annular plate with a curves boundary (especially for elliptical boundaries) in this study. The effect of boundary conditions and hole size on different modes of vibrations is investigated. As the hole size increases, the natural frequencies increase except when the inner and the outer boundaries of the annular elliptic plate are free, for which they decrease with the hole size. (CSA)