NATURAL FREQUENCIES FOR CANTILEVERED LAMINATED COMPOSITE RIGHT TRIANGULAR AND TRAPEZOIDAL PLATES

The first known natural frequencies for cantilevered laminated composi te angle-ply triangular and trapezoidal plates are presented. The Ritz method with non-orthogonal algebraic polynomials has been used to obt ain them. Detailed convergence studies are made and show that relative ly accurate results can be obtained. Comparisons with experimental and analytical frequencies available in the literature for isotropic cant ilevered triangular plates are made. The present method is shown to be superior to other methods used previously to obtain natural frequenci es for this problem. Results are then obtained and listed for the lowe st six frequencies, and for a set of various shapes of right triangula r and trapezoidal thin plates.