D Sirati - Department of Mechanical Engineering, Islamic Azad University, Karaj Branch, Karaj, Iran
R Madoliat - Department of Mechanical Engineering, Iran University of Science and Technology, Tehran
M Alibabaie - Department of Mechanical Engineering, Islamic Azad University, Karaj Branch, Karaj, Iran

In this paper, free vibration analysis of rectangular sandwich plates with functionally graded core is investigated using second order shear deformation theory. In functionally graded plate, the material properties are assumed to vary in an power law in thickness direction with the Poisson ratio to be constant. The equilibrium equations are derived by using energy method and then solved analytically by using Navier's method for a rectangular sandwich plate with simply supported boundary conditions. Natural frequencies for different mode shape are compared and verified with the known results in the literature. Finally the effects of grading index, width to thickness ratio and length to width ration on the frequency are investigated.

FGM, Free Vibration, SSDT