Analysis of functionally graded rotating disks with variable thickness

Abstract

Elastic solutions for axisymmetric rotating disks made of functionally graded material with variable thickness are presented. The material properties and disk thickness profile are assumed to be represented by two power-law distributions. In the case of hollow disk, based on the form of the power-law distribution for the mechanical properties of the constituent components and the thickness profile function, both analytical and semi-analytical solutions are given under free-free and fixed-free boundary conditions. For the solid disk, only semianalytical solution is presented. The effects of the material grading index and the geometry of the disk on the stresses and displacements are investigated. It is found that a functionally graded rotating disk with parabolic or hyperbolic convergent thickness profile has smaller stresses and displacements compared with that of uniform thickness. It is seen that the maximum radial stress for the solid functionally graded disk with parabolic thickness profile is not at the centre like uniform thickness disk. Results of this paper suggest that a rotating functionally graded disk with parabolic concave or hyperbolic convergent thickness profile can be more efficient than the one with uniform thickness.

The Karush–Kuhn–Tucker optimality conditions in minimum weight design of elastic rotating disks with variable thickness and density

“…Rotating disks with variable density can be considered as functionally graded materials (FGM) and the literatures devoted to this field is rich (Gamer, 1985;Güven, 1992;Bayat et al, 2008). Although, other material properties such as modulus of elasticity can also be assumed to vary with disk radius, in this research it is arbitrary decided to assume that Young's modulus is constant as the case reported in the previous studies (Gamer, 1985;Güven, 1992;Hojjati & Jafari, 2008;Hojjati & Jafari, 2009).…”

Numerical creep analysis of FGM rotating disc with GDQ method

“…Creep deformation can affect the performance of systems entirely. As an example, in a turbine rotor there is always a possibility that the heat from the external surface is transmitted to the shaft and then to the bearings, which has adverse effects on the functioning and efficiency of the rotor (Bayat et al, 2008). Under high thermo-mechanical loading, the monolithic materials cannot do well.…”

Elastic and Viscoelastic Stresses of Nonlinear Rotating Functionally Graded Solid and Annular Disks with Gradually Varying Thickness

“…They investigated the constitutive relations of stresses and strains in the thermally loaded rotating variable-thickness elastic disks. Bayat et al [15][16][17][18] dealt with two problems, the elastic and thermoelastic for rotating FG disks at steady temperature. They assumed that the material properties and thickness of the disk are considered according power-law functions of r. Zenkour [19,20] studied the stress distribution in rotating sandwich solid disks with a FG core and isotropic face sheets.…”