In this paper, the thermo-elastoplastic behaviors of rotating sandwich nonuniform thickness annular discs made of functionally graded materials are evaluated using the numerical finite difference method. The sandwich disc is composed of number of equal width layers, and each layer has its own volume fraction. The temperature dependency of the constituent materials is considered; hence, the thermomechanical properties are functions of both position and temperature. The plasticity analysis is accomplished based on the modified Tamura-Tomota-Ozawa model and von Mises yielding criterion. The effects of angular speed, number of layers, thickness profile, and boundary conditions on the stresses and displacements are investigated. Since failure may occur at the interface between the successive layers, the circumferential stress-jumps at the interfaces are also considered. Results ascertain that the temperature dependency of the properties highly influences the disc behaviors. In addition, better disc performance is obtained by increasing the number of layers and/or decreasing the angular speed.

In this paper, the particle swarm optimization method is used to reduce the weight of a multilayer rotating nonuniform thickness disc along with alleviation of the maximum tangential stress and the maximum tangential stress-jump at the interfaces. The proposed disc is made of functionally graded material and is subjected to both mechanical pressure and thermal loads. It is divided into several layers with each one having its unique volume fraction. These volume fractions are considered the design variables of the optimization problem along with two geometrical parameters related to the disc thickness. The equilibrium equation in polar coordinates are solved using the finite difference method. A punch of optimization results is calculated and discussed. It is concluded that the range of design variables’ variation widens by considering more layers. Finally, there is no potential disc configuration or geometry is found dominant to enhance the design parameters concurrently. Therefore, performing similar optimization analyses is compulsory to obtain an efficient and durable structure.