Differential transform vibration and modal stress analyses of circular plates made of two-directional functionally graded materials resting on elastic foundations

In the present paper, the differential transformation method is employed to develop a semi-analytical solution for free vibration and modal stress analyses of two-dimensional functionally graded circular plates resting on two-parameter elastic foundations. Simultaneous variations of the material properties in the radial and transverse directions are described by a general function. Some comprehensive sensitivity analyses are performed, and the natural frequencies and the modal stresses are extracted for free, simply supported, and clamped boundary conditions and different combinations of the geometric, material, and foundation parameters. Therefore, very complex combinations of the material properties, boundary conditions, and parameters of the elastic foundation are considered in the present semi-analytical solution approach. Thus, many novelties are included in the present research. Comparisons made between the present results and results reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. Moreover, the paper treats some interesting problems, for the first time.