UNIVERSITY OF PORTO - FACULTY OF ENGINEERING GEOMETRICALLY NON-LINEAR OSCILLATIONS OF COMPOSITE LAMINATED PLATES BY THE HIERARCHICAL FINITE ELEMENT METHOD by Rui Pedro Monteiro Amaro Duarte, with a degree in Apllied Mathematics, University of Coimbra, Faculty of Sciences Thesis submitted in fulfilment of the degree of Master In Computational Methods in Sciences and Engineering Thesis under the supervision of Dr. Pedro Leal Ribeiro, From the Department of Mechanical Engineering and Industrial Management, Section of Applied Mechanics from the Faculty of Engineering of University of Porto Porto, October 2004