FREE VIBRATION OF SKEW SANDWICH PLATES WITH LAMINATED FACINGS

Abstract

This paper is concerned with the free vibration of skew sandwich plates composed of an orthotropic core and laminated facings. The p -Ritz method has been adopted for the analysis. The Ritz functions are formed from the product of mathematically complete polynomials and boundary equations raised to appropriate integer powers depending on the boundary conditions. The boundary equations ensure the satisfaction of the geometric boundary conditions a priori and facilitate the handling of any type of boundary conditions. For generality, better accuracy and ease in imposition of geometric boundary condition for the oblique edges, the Ritz formulation was non-dimensionalized and cast in the skew co-ordinates system. Since no vibration solutions are available for such skew sandwich plates, the validity, convergence and accuracy of the Ritz formulation were established by comparing with other researchers' vibration frequencies for various subset plate problems involving rectangular sandwich plates and skew laminated plates. The paper features extensive generic vibration frequencies of these skew sandwich plates for various aspect ratios and boundary conditions, lamination designs of facings, material properties of core and facings.