Rotating disk

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1 - Thermo-Elastic and Time-Dependent Creep Evolution Behaviour of Ferritic Steel Rotating Disks using Theta Projection Concept
H. Daghigh V. Daghigh

In this article, thermo-elastic and creep evolution behaviour of ferritic steel rotating disks with variable thickness are investigated. Four thickness profiles of uniform, convex, concave and linear are considered for the disk geometry. The material creep constitutive چکیده کامل

In this article, thermo-elastic and creep evolution behaviour of ferritic steel rotating disks with variable thickness are investigated. Four thickness profiles of uniform, convex, concave and linear are considered for the disk geometry. The material creep constitutive model is defined by the Θ projection concept, based on the experimental results existing in the literature. Loading applied is due to the inertial body force caused by the rotation and a constant temperature field throughout the disk. To achieve history of stresses and displacements, a numerical procedure using finite difference and Prandtl-Reuss relations is used. Stress and deformation histories are calculated using successive elastic solution method. In order to verify the solution approach, both composite and aluminum rotating disks were taken into account and the thermo-elastic and time-dependent creep behaviours for composite as well as the former for aluminum were obtained. Results from the current study were found to be in very good agreement with those available from literature in the area. It was shown that convex thickness profile disks display the least creep displacement, creep effective and circumferential stresses. Additionally, constant and concave thickness profiles were positively correlated with time while for linear and convex ones, it was found to have an inverse trend. پرونده مقاله

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2 - Vibration Analysis of Rotating Disk Carrying Annular Concentrated Masses in Turbo-pump System
Behrooz Shahriari Mostafa Nazemizadeh A. M. Shirvani

10.30486/admt.2023.697496

Vibration analysis of rotating disks is one of the most important problems in turbomachines. In this study, a new method has been presented which analyzed the radial vibration of a turbo-pump rotating disk carrying two annular concentrated masses located on the disk and چکیده کامل

Vibration analysis of rotating disks is one of the most important problems in turbomachines. In this study, a new method has been presented which analyzed the radial vibration of a turbo-pump rotating disk carrying two annular concentrated masses located on the disk and at its end. Natural frequencies have been calculated in different rotating speeds; then results have been compared with each other. The effects of concentrated masses position and intensity on natural frequencies have been investigated. The results show that concentrated masses always have been decreased the value of first natural frequency, but in the case of second and third natural frequencies, depending on the mass concentration magnitude and its position, the magnitude of natural frequency has been increased or decreased. The vibration of the rotating disk without considering the concentrated mass, was examined. Then the resulting solution was generalized for two connected disks in internal concentrated mass location. The effect of concentrated masses, one on the disk body and the other on the outside of the disk, is considered as boundary conditions in the two disk Equations. The results show that increasing in angular velocity of rotating disk reduces the natural frequency. Concentrated masses always reduce the first natural frequency. At the second and third natural frequencies, concentrated masses may increase or decrease the natural frequency, which depends on the value and position of concentrated mass. Concentrated mass has the most impact when it is in a position that has the most radial displacement. پرونده مقاله

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3 - Inhomogeneity Material Effect on Electromechanical Stresses, Displacement and Electric Potential in FGM Piezoelectric Hollow Rotating Disk
A Ghorbanpour Arani H Khazaali M Rahnama M Dadkhah

In this paper, a radially piezoelectric functionally graded rotating disk is investigated by the analytical solution. The variation of material properties is assumed to follow a power law along the radial direction of the disk. Two resulting fully coupled differential e چکیده کامل

In this paper, a radially piezoelectric functionally graded rotating disk is investigated by the analytical solution. The variation of material properties is assumed to follow a power law along the radial direction of the disk. Two resulting fully coupled differential equations in terms of the displacement and electric potential are solved directly. Numerical results for different profiles of inhomogeneity are also graphically displayed. پرونده مقاله

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4 - Magneto-Thermo-Elastic Stresses and Perturbation of the Magnetic Field Vector in an EGM Rotating Disk
A Ghorbanpour Arani M Azamia H Sepiani

In this article, the magneto-thermo-elastic problem of exponentially graded material (EGM) hollow rotating disk placed in uniform magnetic and temperature fields is considered. Exact solutions for stresses and perturbations of the magnetic field vector in EGM hollow rot چکیده کامل

In this article, the magneto-thermo-elastic problem of exponentially graded material (EGM) hollow rotating disk placed in uniform magnetic and temperature fields is considered. Exact solutions for stresses and perturbations of the magnetic field vector in EGM hollow rotating disk are determined using the infinitesimal theory of magneto-thermo-elasticity under plane stress. The material properties, except Poisson’s ratio, are assumed to depend on variable of the radius and they are expressed as exponential functions of radius. The direct method is used to solve the heat conduction and Hyper-geometric functions are employed to solve Navier equation. The temperature, displacement, and stress fields and the perturbation of the magnetic field vector are determined and compared with those of the homogeneous case. Hence, the effect of in-homogeneity on the stresses and the perturbation of magnetic field vector distribution are demonstrated. The results of this study are applicable for designing optimum EGM hollow rotating disk. پرونده مقاله

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5 - Exact Solution for Electrothermoelastic Behaviors of a Radially Polarized FGPM Rotating Disk
A Ghorbanpour Arani A Jafarzadeh Jazi M Abdollahian M.R Mozdianfard M Mohammadimehr S Amir

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 چکیده کامل

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. پرونده مقاله

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6 - Magneto-Thermo-Elastic Stresses and Perturbation of Magnetic Field Vector in a Thin Functionally Graded Rotating Disk
A Ghorbanpour Arani S Amir

In this paper, a semi-analytical solution for magneto-thermo-elastic problem in an axisymmetric functionally graded (FG) hollow rotating disk with constant thickness placed in uniform magnetic and thermal fields with heat convection from disk’s surfaces is present چکیده کامل

In this paper, a semi-analytical solution for magneto-thermo-elastic problem in an axisymmetric functionally graded (FG) hollow rotating disk with constant thickness placed in uniform magnetic and thermal fields with heat convection from disk’s surfaces is presented. Solution for stresses and perturbation of magnetic field vector in a thin FG rotating disk is determined using infinitesimal theory of magneto-thermo-elasticity under plane stress conditions. The material properties except Poisson’s ratio are modeled as power-law distribution of volume fraction. The non-dimensional distribution of temperature, displacement, stresses and perturbation of magnetic field vector throughout radius are determined. The effects of the material grading index and the magnetic field on the stress and displacement fields are investigated. The results of stresses and radial displacements for two different boundary conditions are compared with the case of a thin FG rotating disk with the same loading and boundary conditions but in the absence of magnetic field. It has been found that imposing a magnetic field significantly decreases tensile circumferential stresses. Therefore, the fatigue life of the disk will be significantly improved by applying the magnetic field. The results of this investigation can be used for optimum design of rotating disks. پرونده مقاله

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7 - Elastic Analysis of Functionally Graded Variable Thickness Rotating Disk by Element Based Material Grading
A.K Thawait L Sondhi Sh Sanyal Sh Bhowmick

The present study deals with the elastic analysis of concave thickness rotating disks made of functionally graded materials (FGMs).The analysis is carried out using element based gradation of material properties in radial direction over the discretized domain. The resul چکیده کامل

The present study deals with the elastic analysis of concave thickness rotating disks made of functionally graded materials (FGMs).The analysis is carried out using element based gradation of material properties in radial direction over the discretized domain. The resulting deformation and stresses are evaluated for free-free boundary condition and the effect of grading index on the deformation and stresses is investigated and presented. The results obtained show that there is a significant reduction of stresses in FGM disks as compared to homogeneous disks and the disks modeled by power law FGM have better strength. پرونده مقاله

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8 - Stress analysis of non-linearly variable thickness rotating disk in gas turbine engine using hyper-geometric method
Behrooz Shahriari Nedasadat Seddighi

In this paper, the numerical and exact analytical calculation of elastic strains and stresses in gas turbine engine rotating disk with variable thickness, subjected to temperature gradient are presented. Galerkin method is applied to solve any kind of profiles with arbi چکیده کامل

In this paper, the numerical and exact analytical calculation of elastic strains and stresses in gas turbine engine rotating disk with variable thickness, subjected to temperature gradient are presented. Galerkin method is applied to solve any kind of profiles with arbitrary thickness, temperature and density functions while the other numerical and analytical methods used in previous works, are applied to profiles with certain thickness functions. Therefore, a comprehensive approach that takes all the circumstances into account was used in an attempt to fill this gap. To verify the numerical method, a few examples of rotating disks with non-linear variable thicknesses were solved using the analytical method as a reference method and their results were compared with numerical solution. A good agreement between numerical and analytical solutions was observed. In the analytical part, a new method to convert equilibrium equation of rotating disks to hyper-geometric differential equation was provided and then it was solved. Using hyper-geometric method is the main novelty of this research. The distributions of radial displacement and stresses were obtained and an appropriate comparisons and discussions were made at the same environmental conditions. پرونده مقاله

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9 - Nonlinear Finite Element Analysis of Thermoelastic Stresses of FGM Rotating Disk Considering Temperature-Dependency of Material Properties
مهرنوش دمیرچلی محمد آزادی

In the present paper, nonlinear radial and hoop thermoelastic stresses analysis of a disk made of FGMs material is investigated. According to this purpose, finite element method is used. In the present method, second-order one-dimensional element (with three node points چکیده کامل

In the present paper, nonlinear radial and hoop thermoelastic stresses analysis of a disk made of FGMs material is investigated. According to this purpose, finite element method is used. In the present method, second-order one-dimensional element (with three node points) is proposed. The geometrical and stress boundary conditions are defined in the state of non-existence of external pressure and then zero radial stress in the outer layer of the disk, and zero displacement in the center of the disk. Also the temperature distribution is assumed as linear. The material properties changes including temperature-dependency are modeled. Finally, a numerical example is proposed to show the radial displacements, radial and hoop thermoelastic stresses versus radius of the disk for different power (N) from Power-law and different angular velocities. The results show that by increasing both two parameters, N and angular velocity of the disk, the amounts of displacement and stress are increased. At last, temperature-dependency and temperature-independency of material properties is investigated. پرونده مقاله

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