Dynamic Stiffness Method for Free Vibration of Moderately Thick Functionally Graded Plates

In this study, a dynamic stiffness method for free vibration analysis of moderately thick function-ally graded material plates is developed. The elasticity modulus and mass density of the plate are assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents whereas Poisson’s ratio is constant. Due to the variation of the elastic properties through the thickness, the equations of motion governing the in-plane and transverse deformations are initially coupled. Using a new reference plane instead of the mid-plane of the plate, the uncoupled differential equations of motions are derived. The out-of-plane equations of motion are solved by introducing the auxiliary and potential functions and using the separation of variables method. Using the method, the exact natural frequencies of the Functionally Graded Plates (FGPs) are obtained for different boundary conditions. The accuracy of the natural frequencies obtained from the present dynamic stiffness method is evaluated by comparing them with those obtained from the methods suggested by other researchers.