In this paper energy method is used to calculate rotor response with loose Rotating Disk on it. System equation of motion is obtained based on energy method and Lagrange equation. Mathematical modeling of loose Disk in a rotor bearing system has resulted in terms similar to unbalance and gyroscopic effect in the system equation of motion. The effect of loose Disk axial position and orthotropic bearing has been considered in this investigation. By assuming that shaft and loose Disk are always in contact, the results of these study shows that clearance between loose Disk and shaft, shaft speed, mass and mass moment of inertia of Disk have a major effect on a rotor response and beating phenomena.

This article presents an exact solution for an axisymmetric functionally graded piezoelectric (FGP) Rotating Disk with constant thickness subjected to an electric field and thermal gradient. All mechanical, thermal and piezoelectric properties except for Poisson's ratio are taken in the form of power functions in radial direction. After solving the heat transfer equation, first a symmetric distribution of temperature is produced. The gradient of displacement in axial direction is then obtained by assuming stress equation in axial direction to be zero. The electric potential gradient is attained by charge and electric displacement equations. Substituting these terms in the equations for the dimensionless stresses in the radial and circumferential directions yield these stresses and using them in the mechanical equilibrium equation a nonhomogeneous second order differential equation is produced that by solving it, the dimensionless displacement in radial direction can be achieved. The study results for a FGP Rotating hollow Disk are presented graphically in the form of distributions for displacement, stresses and electrical potential.

The analysis of the bending behavior of Rotating porous Disks with exponential thickness variation consisting of viscoelastic functionally graded material is illustrated. The study of bending in the porous Disk was done using the first-order shear deformation theory. The porous Disk is under the effect of a combination of mechanical stresses and thermal distribution. All material factors for the porous Disk change across the thickness as a power law of radius. To solve the mathematical structure by using the semi-analytical technique for displacements in the porous Disk, and then to treat the structure model with viscoelastic material by the correspondence principle and Illyushin’s approximation manner. Numerical outcomes including the effect of porosity parameter, inhomogeneity factor, and relaxation time are presented with three different sets of boundary conditions for the solid and hollow Disks. A comparison between porous and perfect Disk with numerous values of porosity parameters and different inhomogeneity factors have been shown to emphasize the importance of complex mathematical structure in modern engineering mechanical designs.

The correct materials selection in the design of aerospace structures reduces the weight and increases structural efficiency. Since the rotor in gas turbine engines has a significant weight, it is important to reduce its weight. The Rotating Disks in these rotors are subjected to mechanical and thermal loads and experience high-temperature gradients and angular velocities. This work aims to analyze the stress of a Rotating Disk made of carbon-carbon (C/C) composite to withstand mechanical and thermal loads and reduce the weight of the rotor. The behavior of constant thickness C/C composite Disks is studied based on the Tsai-Wu Failure Theory. To do so, first, the basic properties of the material, Disk size, rotation speed, temperature distribution, and other requirements are determined. The differential governing equations are obtained by assuming the plane stress state, Hooke's law, and compatibility condition, and the stresses, strains, and displacements are obtained. Considering the safety factors of 1 and 1.5, the critical velocities are calculated using the Tsai-Wu failure theory. Finally, according to the information obtained from the analysis, the evaluation of Disks with different layers is compared with other similar Disks made with different materials.

This paper is dealing with the Elastoplastic analysis of Rotating Disks of variable thickness made of functionally graded materials based on Tresca's yield criterion. To do so, the governing equations of Rotating annular Disks are established based on the elasticity theory. Then, using Tresca's yield criterion and the elastic-perfectly plastic flow law, the displacement equations and stresses are obtained in the plastic region. In order to find the effects of the shape of the Disk profile on its stress distribution, the thickness of the Disk cross-section is supposed to vary as an exponential function of the radius. In addition, considering different places at which the yielding starts, the process of expanding the plastic flow is investigated. The obtained results are validated against those reported for homogeneous as well as constant thickness FGM Disks, showing good agreement. The findings also demonstrate that taking the variable thickness for the Disk cross-section into account has a significant effect on the stress distribution and prediction of the place where the yielding initiate.

The three-dimensional problem of steady fluid deposition on an inclined Rotating Disk is illustrated in this study. The governing non-linear partial differential equations are reduced to the nonlinear ordinary differential equations system by similarity transform. The analytical solution applied to solve this system is the Homotopy Perturbation Method (HPM). The velocity and temperature profiles are shown and the influence of Prandtl number and rotation ratio on the flow field and the Nusselt number are discussed in detail. The validity of our solutions is verified by the numerical results.