Vibrational response of symmetrically laminated trapezoidal composite plates with point constraints

This paper presents the first known results for free vibrations of thin, points-supported, symctrically laminated trapezoidal composite plates. The solution method developed is based on the Rayleigh Ritz method and the admissible 2-D orthogonal polynomials to derive the governing eigenvalue equation. The natural frequencies and mode shapes for the laminated plates are obtained by solving this governing eigenvalue equation. Several test problems are solved to demonstrate the accuracy and flexibility of the proposed method. The effects of fibre orientations, points location and the number of layers in the stacking sequences on the vibrational response for the plate problems are investigated. Variation of spring constants for the clastic points on the effect of the frequency Parameters is also considered. © 1992.