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. | Volume 35 Number 4 4 Vietnam Journal of Mechanics, VAST, Vol. 35, No. 4 (2013), pp. 257 – 274 FREE VIBRATION OF THICK COMPOSITE PLATES ON NON-HOMOGENEOUS ELASTIC FOUNDATIONS BY DYNAMIC STIFFNESS METHOD Nguyen Manh Cuong, Tran Ich Thinh∗ , Ta Thi Hien, Dinh Gia Ninh Hanoi University of Science and Technology, Vietnam ∗ E-mail: tranichthinh@ Abstract. 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. Keywords: Vibration of thick composite plate, continuous element method, dynamic stiffness matrix, Pasternak foundation, non-homogenous foundation. 1. INTRODUCTION Laminated composite plates on elastic foundations have been widely used in many engineering application such as aerospace, automotive, marine and other structural applications because of advantageous features. Many researches are carried out in order to design safer and more economic thick laminated composite plate structures supported by non-homogenous elastic foundations which represent a vast amount of usages in industry. The elastic foundation can be modeled by different models: Winkler model and twoparameter Pasternak model. If the second parameter vanished, the .
