This research presents a new model for vibration analysis of thick laminated plates on a non-homogeneous elastic foundation by the Dynamic Stiffness Method (DSM). The non-homogeneous foundation consists of multi-segment Winkler-type and Pasternak-type elastic foundation. The Dynamic Stiffness Matrices using the First Shear Deformation Theory (FSDT) are constructed for cross-ply thick composite plates. A computer program is written using the present formulation for calculating natural frequencies and harmonic response of composite plates subjected to various types of boundary conditions. Numerical results are validated by comparison with available results in the literature and with Finite Element Method (FEM). Different test cases make evidence the advantages of the present model: higher precision, less data storage, less computing time and studied frequency range extended.

This paper presents the vibration analysis of thick laminated composite cylindrical shells by a new approach using the Continuous Element Method (CEM). Based on the analytical solutions for the differential equations of thick composite cylindrical shell taking into account shear deflection effects, the dynamic transfer matrix is built from which natural frequencies are easily calculated. A computer program is developed for performing numerical calculations and results from specific cases are presented. Numerical results of this work are compared with published analytical and Finite Element Method (FEM) results. Through different examples, advantages of CEM are confirmed: reduced size of model, higher precision, reduced time of computation and larger range of studied frequencies.

In this investigation, by an analytical approach, the influence of several key parameters, especially the temperature on the sound isolation capacity of the symmetrically finite orthotropic laminated composite plate is studied. The plate is modeled with classic thin-plate theory and is assumed to be simply supported on all four sides. The incident acoustic pressure is modeled as a harmonic plane wave impinging on the plate at an arbitrary angle. The sound transmission loss is calculated from the ratio of incident to transmitted acoustic powers