In recent years functionally graded plates are widely used in turbines, reactor vessels, aerospaces and other engineering applications due to their advantages of being able to resist high temperature gradient. FGM’s are usually made from a mixture of ceramics and metals which in ceramic provides the high temperature resistance due to it’s low thermal conductivity and metal constituent supplies high stiffness and ductility of the plate. The properties of this plates vary smoothly and continuously through the thickness. This variation usually obtains by a power low function. For simplicity and due to small variation of the Poisson’s ratio It is assumed to be constant through the thickness. In this thesis mechanical and thermal buckling and free vibration of functionally graded plates resting on an elastic foundation are studied. The winkler and Pasternak foundation are used to model the mechanical behavior of elastic foundation. In order to consider shear deformation, refined plate theory is employed. In this theory out of plane displacement includes two components of bending and shear . Distributio of shear strain is obtained by means of a hyperbolic function which satisfies the free transverse shear stress condition on top and bottom of the plate therefore in this theory there is no need to consider shear correction factor. An ordinary finite strip method is used to analyse the buckling and free vibration of plates. By comparing numerical results with other references it can be concluded that using the finite strip method in company with refined plate theory yields satisfactory results and the number of degrees of freedom are reduced in comparison with third order shear deformation theory. Results are presented for different boundary conditions in tables and graphs. The effects of aspect ratio, volume fraction index, elastic foundation are presented in several tables and graphs. Keywords : Refined plate theory, Thick functionally graded plates, Mechanical buckling, Thermal buckling, Free vibration, Finite strip method
