Design functionally graded rotating disks under thermoelastic loads: Weight optimization

Highlights: • An effective design algorithm for functionally graded rotating disks. • Weight optimization of functionally graded rotating disks with different thickness. • Thermal effects are considered as well as those of the centrifugal impacts. • Optimized profiles of functionally graded disks with different angular velocities and grading indexes. - Abstract: In this work, an advanced algorithm is employed to optimize the weight of a functionally graded hollow circular disk of varied thickness rotating at a constant angular velocity about its central axis. The disk is under thermoelastic load conditions. The material properties, encompassing elastic modulus thermal expansion coefficient, thermal conductivity, and density and thickness of the disk are assumed to be graded in the radial direction, and the Poisson's ratios are assumed to be constant. A combination of a co-evolutionary particle swarm optimization (CPSO) approach coupled with a differential quadrature (DQ) method is applied to obtain minimized stress and displacement fields through the geometry of the disk. The role of DQ is discretizing and solving the governing equations including motion and boundary conditions existing in the goal function of the CPSO method. In comparisons with other optimization results in the literature, the weight reduction results of this algorithm show much superior responses, demonstrating the effectiveness of this algorithm for optimizing constrained complex problems in engineering structures. Also, in numerical simulation, a study is performed to determine the effects of angular velocity and gradient index variations on the distribution of stress and displacement fields.