Axisymmetric

دسترسی آزاد مقاله

1 - A Simple Method for Designing a Duct for a Multi-Component Ducted Propulsion System
N. M. Nouri Mehrdad Kalantar Neyestanaki Saber Mohammadi

The present paper numerically discusses the design procedure of marine ducts used for multi-component ducted propulsion systems at the stern of an axisymmetric submerged body. The results are presented in the form of tables showing the effects of dihedral angel as well چکیده کامل

The present paper numerically discusses the design procedure of marine ducts used for multi-component ducted propulsion systems at the stern of an axisymmetric submerged body. The results are presented in the form of tables showing the effects of dihedral angel as well as camber ratio of the duct as the two most important geometrical parameters on hydrodynamic performance of the propulsion system. Furthermore, a correlation has been extracted between the results of two and three dimensional analysis of ducted propellers. The results show that the design procedure of the duct used for a ducted propulsion system could be performed using some two dimensional analyses. The simulations are performed using a Reynolds averaged Navier Stokes Equations (RANS) based Computational Fluid Dynamics (CFD) tool. پرونده مقاله

دسترسی آزاد مقاله

2 - An Axisymmetric Contact Problem of a Thermoelastic Layer on a Rigid Circular Base
F Guerrache B Kebli

10.22034/jsm.2019.668619

We study the thermoelastic deformation of an elastic layer. The upper surface of the medium is subjected to a uniform thermal field along a circular area while the layer is resting on a rigid smooth circular base. The doubly mixed boundary value problem is reduced to a چکیده کامل

We study the thermoelastic deformation of an elastic layer. The upper surface of the medium is subjected to a uniform thermal field along a circular area while the layer is resting on a rigid smooth circular base. The doubly mixed boundary value problem is reduced to a pair of systems of dual integral equations. The both system of the heat conduction and the mechanical problems are calculated by solving a dual integral equation systems which are reduced to an infinite algebraic one using a Gegenbauer’s formulas. The stresses and displacements are then obtained as Bessel function series. To get the unknown coefficients, the infinite systems are solved by the truncation method. A closed form solution is given for the displacements, stresses and the stress singularity factors. The effects of the radius of the punch with the rigid base and the layer thickness on the stress field are discussed. A numerical application is also considered with some concluding results. پرونده مقاله

دسترسی آزاد مقاله

3 - Effect of Winkler Foundation on Radially Symmetric Vibrations of Bi-Directional FGM Non-Uniform Mindlin’s Circular Plate Subjected to In-Plane Peripheral Loading
N Ahlawat R Lal

10.22034/jsm.2019.1873720.1466

An analysis has been presented of the effect of elastic foundation and uniform in-plane peripheral loading on the natural frequencies and mode shapes of circular plates of varying thickness exhibiting bi-directional functionally graded characteristics, on the basis of f چکیده کامل

An analysis has been presented of the effect of elastic foundation and uniform in-plane peripheral loading on the natural frequencies and mode shapes of circular plates of varying thickness exhibiting bi-directional functionally graded characteristics, on the basis of first order shear deformation theory. The material properties of the plate are varying following a power-law in both the radial and transverse directions. The numerical solutions of the coupled differential equations leading the motion of simply supported and clamped plates acquired by using Hamilton’s principle, is attained by harmonic differential quadrature method. The effect of different plate parameters namely gradient index, heterogeneity parameter, density parameter, taper parameter and thickness parameter is illustrated on the vibration characteristics for the first three modes of vibration for various values of in-plane peripheral loading parameter together with foundation parameter. Critical buckling loads in compression are calculated for both the boundary conditions by putting the frequencies to zero. The reliability of the present technique is confirmed by comparing the results with exact values and results of published work. پرونده مقاله

دسترسی آزاد مقاله

4 - Mechanical and Thermal Stresses in a FGPM Hollow Cylinder Due to Non-Axisymmetric Loads
M Jabbari M Meshkini M.R Eslami

In this paper, the general solution of steady-state two-dimensional non-axisymmetric mechanical and thermal stresses and mechanical displacements of a hollow thick cylinder made of fluid-saturated functionally graded porous material (FGPM) is presented. The general form چکیده کامل

In this paper, the general solution of steady-state two-dimensional non-axisymmetric mechanical and thermal stresses and mechanical displacements of a hollow thick cylinder made of fluid-saturated functionally graded porous material (FGPM) is presented. The general form of thermal and mechanical boundary conditions is considered on the inside and outside surfaces. A direct method is used to solve the heat conduction equation and the non-homogenous system of partial differential Navier equations, using the Complex Fourier Series and the power law functions method. The material properties, except of Poisson's ratio, are assumed to depend on the radial variable r and they are expressed as power law functions. پرونده مقاله

دسترسی آزاد مقاله

5 - Free Vibration Analysis of Orthotropic FGM Cylinders by a Mesh-Free Method
R Moradi-Dastjerdi M Foroutan

In this paper, free vibration analysis of orthotropic functionally graded material (FGM) cylinders was carried out by a Mesh-Free method. In this analysis, moving least squares shape functions are used for approximation of displacement field in the weak form of equilibr چکیده کامل

In this paper, free vibration analysis of orthotropic functionally graded material (FGM) cylinders was carried out by a Mesh-Free method. In this analysis, moving least squares shape functions are used for approximation of displacement field in the weak form of equilibrium equation. Essential boundary conditions are imposed by transformation method. In this simulation, an axisymmetric model is used. The orthotropic FGM cylinders are assumed to be a mixture of two isotropic materials as fiber and matrix. The volume fraction of the fiber is changed in the radial direction. Consequently, mechanical properties of these cylinders are changed in the radial direction. Free vibration analysis of orthotropic FGM cylinders with any arbitrary combination of boundary conditions is possible by the proposed model. Natural frequencies obtained from the presented model are in good agreement with results of finite element simulation and other results from literature. Effects of various types of boundary conditions, geometrical parameters, and mechanical properties on the natural frequencies are studied. پرونده مقاله

دسترسی آزاد مقاله

6 - Generalized Thermoelastic Problem of a Thick Circular Plate with Axisymmetric Heat Supply Due to Internal Heat Generation
J.J Tripathi G.D Kedar K.C Deshmukh

A two dimensional generalized thermoelastic problem of a thick circular plate of finite thickness and infinite extent subjected to continuous axisymmetric heat supply and an internal heat generation is studied within the context of generalized thermoelasticity. Unified چکیده کامل

A two dimensional generalized thermoelastic problem of a thick circular plate of finite thickness and infinite extent subjected to continuous axisymmetric heat supply and an internal heat generation is studied within the context of generalized thermoelasticity. Unified system of equations for classical coupled thermoelasticity, Lord-Shulman and Green-Lindsay theory is considered. An exact solution of the problem is obtained in the transform domain. Inversion of Laplace transforms is done by employing numerical scheme. Mathematical model is prepared for Copper material plate and the numerical results are discussed and represented graphically. پرونده مقاله

دسترسی آزاد مقاله

7 - Axisymmetric Problem of Thick Circular Plate with Heat Sources in Modified Couple Stress Theory
R Kumar Sh Devi V Sharma

The main aim is to study the two dimensional axisymmetric problem of thick circular plate in modified couple stress theory with heat and mass diffusive sources. The thermoelastic theories with mass diffusion developed by Sherief et al. [1] and kumar and Kansal [2] have چکیده کامل

The main aim is to study the two dimensional axisymmetric problem of thick circular plate in modified couple stress theory with heat and mass diffusive sources. The thermoelastic theories with mass diffusion developed by Sherief et al. [1] and kumar and Kansal [2] have been used to investigate the problem. Laplace and Hankel transforms technique is applied to obtain the solutions of the governing equations. The displacements, stress components, temperature change and chemical potential are obtained in the transformed domain. Numerical inversion technique has been used to obtain the solutions in the physical domain. Effects of couple stress on the resulting quantities are shown graphically. Some particular cases of interest are also deduced. پرونده مقاله

دسترسی آزاد مقاله

8 - Axisymmetric Buckling Analysis of Porous Truncated Conical Shell Subjected to Axial Load
M Zarghami Dehaghani M Jabbari

This paper studied Buckling analysis of porous truncated conical shell subjected to axial load. It is considered that a fluid undrained between porous material and the Porous material properties vary across the thickness of shell with a specific function also assumed th چکیده کامل

This paper studied Buckling analysis of porous truncated conical shell subjected to axial load. It is considered that a fluid undrained between porous material and the Porous material properties vary across the thickness of shell with a specific function also assumed that the edge of the shell is simply supported. The governing equations are based on the Sanders kinematics equations and the first-order shell theory and by using of variational formulations. The general mechanical non-linear equilibrium and linear stability equations are derived. At the end, the result of dimensionless buckling critical load ratio dimensionless thickness in different condition such as variation in thickness, porosity and angle of conical shell is investigated. The mechanical load results are verified by the known results in the literature. پرونده مقاله

دسترسی آزاد مقاله

9 - Analytical Solution for Electro-mechanical Behavior of Piezoelectric Rotating Shaft Reinforced by BNNTs Under Non-axisymmetric Internal Pressure
A Ghorbanpour Arani E Haghparast S Amir

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structu چکیده کامل

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structure is modeled based on piezoelectric fiber reinforced composite (PFRC) theory and a representative volume element has been considered for predicting the elastic, piezoelectric and dielectric properties of the composite rotating shaft. Distribution of radial, circumferential, shear and effective stresses and electric displacement in composite rotating shaft are determined based on Fourier series. The detailed parametric study is conducted, focusing on the remarkable effects of angular velocity, electric potential, volume fraction and orientation angle of BNNTs on the distribution of stresses. The results show that properties of the piezoelectric shaft as matrix have significant influence on the electro-mechanical stresses where the PZT-4 has less effective stresses against PVDF. Therefore, PZT-4 could be considered for improving optimum design of rotating piezoelectric shaft under electric field and non-axisymmetric mechanical loadings. پرونده مقاله

دسترسی آزاد مقاله

10 - Electro-Mechanical Buckling of a Piezoelectric Annular Plate Reinforced with BNNTs Under Thermal Environment
A Ghorbanpour Arani E Haghparast

In this article, axisymmetric buckling behavior of piezoelectric fiber reinforced polymeric composite (PFRPC) annular plate subjected to electro-thermo-mechanical field is presented utilizing principle of minimum potential energy. Boron-nitride nanotubes (BNNTs) are use چکیده کامل

In this article, axisymmetric buckling behavior of piezoelectric fiber reinforced polymeric composite (PFRPC) annular plate subjected to electro-thermo-mechanical field is presented utilizing principle of minimum potential energy. Boron-nitride nanotubes (BNNTs) are used as fibers. Full coupling between electrical, mechanical and thermal fields are considered according to a representative volume element (RVE)-based XY piezoelectric fiber reinforce composite (PEFRC) model. Assuming PFRPC material and its composite constituents to be linear, homogenous, orthotropic, and perfectly bonded with uniform applied field, the basic relation for the axisymmetric buckling of a circular plate subjected to radial compression, radial electrical field, and uniform temperature change are derived. The presented results show that BNNTs can be used as an effective supplement to improve mechanical behavior of polyvinylidene fluoride (PVDF). Also, at normal working conditions, the influence of thermal and mechanical fields is much higher than the electric one on the critical load; hence, this smart structure is best suited for applications as sensors than actuators. پرونده مقاله

دسترسی آزاد مقاله

11 - Free Vibration Analysis of Non-Uniform Circular Nanoplate
M Zarei M Ghalami-Choobar G.H Rahimi G.R Faghani

In this paper, axisymmetric free vibration analysis of a circular Nano-plate having variable thickness was studied. The variation in thickness of plate was considered as a linearly in radial direction. Nonlocal elasticity theory was utilized to take into account size-de چکیده کامل

In this paper, axisymmetric free vibration analysis of a circular Nano-plate having variable thickness was studied. The variation in thickness of plate was considered as a linearly in radial direction. Nonlocal elasticity theory was utilized to take into account size-dependent effects. Ritz functions was utilized to obtain the frequency equations for simply supported and clamped boundary. To verify accuracy of Ritz method, differential transform method (DTM) also used to drive the size dependent natural frequencies of circular nano-plates. The validity of solutions was performed by comparing present results with those of the literature for both classical plate and nano plate. Effect of nonlocal parameter, mode number and taper parameter on the natural frequency are investigated. Results showed that taper parameter has significant effect on the non-dimensional frequency and its effects on the clamped boundary condition is more than simply support. پرونده مقاله

دسترسی آزاد مقاله

12 - Mechanical Stresses in a Linear Plastic FGM Hollow and Solid Rotational Disk
M Jabbari A Hatefkia M Shokouhfar

In this paper, an analytical solution for computing the plastic & linear plastic stresses and critical angular velocity in a FGM hollow & solid rotating disk is developed. It has been assumed that the modulus of elasticity and yield strength were varying through چکیده کامل

In this paper, an analytical solution for computing the plastic & linear plastic stresses and critical angular velocity in a FGM hollow & solid rotating disk is developed. It has been assumed that the modulus of elasticity and yield strength were varying through thickness of the FGM material according to a power law relationship. The Poisson's ratio were considered constant throughout the thickness. In the analysis presented here the effect of non-homogeneity in FGM rotating disk was implemented by choosing a dimensionless parameter, named m, which could be assigned an arbitrary value affecting the stresses in the rotating disk. Distribution of stresses in radial and circumferential directions for FGM rotating disk under the influence of angular velocity were obtained. Graphs of variations of stress, critical angular velocity versus radius of the rotating disk were plotted. The direct method is used to solve the Navier equations. پرونده مقاله

دسترسی آزاد مقاله

13 - Analysis of Axisymmetric Extrusion Process through Dies of any Shape with General Shear Boundaries
H Haghighat G.R Asgari

In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by apply چکیده کامل

In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by applying upper bound technique for a streamlined die shape and exponential functions for shear boundaries. It is shown that assuming exponential boundaries for deformation zone yields a die shape with smaller extrusion force than that of by assuming spherical shape boundaries is in agreement with the results obtained by the finite element method. پرونده مقاله

دسترسی آزاد مقاله

14 - Generalized Thermoelastic Problem of a Thick Circular Plate Subjected to Axisymmetric Heat Supply
J.J Tripathi G.D Kedar K.C Deshmukh

The present work is aimed at analyzing the thermoelastic disturbances in a circular plate of finite thickness and infinite extent subjected to constant initial temperature and axisymmetric heat supply. Integral transform technique is used. Analytic solutions for tempera چکیده کامل

The present work is aimed at analyzing the thermoelastic disturbances in a circular plate of finite thickness and infinite extent subjected to constant initial temperature and axisymmetric heat supply. Integral transform technique is used. Analytic solutions for temperature, displacement and stresses are derived within the context of unified system of equations in generalized thermoelasticity in the Laplace transform domain using potential functions. Inversion of Laplace transforms is done by employing a numerical scheme. Temperature, displacement and stresses developed in the thick circular plate are obtained and illustrated graphically for copper (pure) material. پرونده مقاله

دسترسی آزاد مقاله

15 - Non-Axisymmetric Time-Dependent Creep Analysis in a Thick-Walled Cylinder Due to the Thermo-mechanical loading
M Moradi A Loghman

In this study, the non-linear creep behaviour of a thick-walled cylinder made of stainless steel 316 is investigated using a semi-analytical method. The thick-walled cylinder is under a uniform internal pressure and a non-axisymmetric thermal field as a function of the چکیده کامل

In this study, the non-linear creep behaviour of a thick-walled cylinder made of stainless steel 316 is investigated using a semi-analytical method. The thick-walled cylinder is under a uniform internal pressure and a non-axisymmetric thermal field as a function of the radial and circumferential coordinates. For the high temperature and stress levels, creep phenomena play a major role in stress redistributions across the cylinder thickness. The Bailey-Norton creep constitutive equation is used to model the uniaxial creep behaviour of the material. Creep strain increments are accumulated incrementally during the life of the vessel. Creep strain increments are related to the current stresses and the material uniaxial creep model by the well-known Prandtl-Reuss relations. Considering the mentioned non-axisymmetric boundary conditions, the heat conduction equation and the Navier partial differential equations has been solved using the separation of variables and the complex Fourier series methods. The corresponding displacement, strain and stress functions are obtained. Considering the non-axisymmetric loadings, the distribution of the radial, circumferential and shear stresses are studied. Furthermore, the effects of internal pressure and external temperature distribution on the effective stress history are investigated. It has been found that the non-axisymmetric thermal loading has a significant effect on stress redistributions. پرونده مقاله

دسترسی آزاد مقاله

16 - Study of Effective Parameters on Stress and Displacement of Axisymmetric Corrugated Diaphragms
رضا سلامی ناصریان وحید کدخدایی

In this paper, the axisymmetric corrugated diaphragm using finite element method will be discussed, so that half of these diaphragms’ cross sections and later the applied pressure will be considered. Following this, using the consequent equations and visual basic چکیده کامل

In this paper, the axisymmetric corrugated diaphragm using finite element method will be discussed, so that half of these diaphragms’ cross sections and later the applied pressure will be considered. Following this, using the consequent equations and visual basic software, a computer program will be provided which receives the diaphragms’ particulars such as diameter, thickness, pressure and the form of object’s cross section as AutoCAD file and then it measures the maximal stress and displacement. Finally, the calculated values will be compared with the experimental values and Theoretical results using the above program and then it will become clear that the results of this research enjoy the acceptable precision. Then, the various parameters which have an influence on the displacement and stress are changed and the results of these changes will be investigated. پرونده مقاله

دسترسی آزاد مقاله

17 - Fracture analysis of multiple axisymmetric interfacial cracks in an FGM Coated orthotropic layer
Behrooz Momeni

Based on the distributed dislocation technique, an analytical solution for the orthotropic layer with functionally graded material (FGM) orthotropic coating containing multiple axisymmetric interfacial cracks subjected to torsional loading is investigated. It is assumed چکیده کامل

Based on the distributed dislocation technique, an analytical solution for the orthotropic layer with functionally graded material (FGM) orthotropic coating containing multiple axisymmetric interfacial cracks subjected to torsional loading is investigated. It is assumed that the material properties of the FGM orthotropic coating vary power-law form along the thickness of the layer. At first, by using the Hankel transform, the solution for Somigliana type rotational ring dislocation in the layer and its coating is obtained. Then, the dislocation solution is used to derive a set of singular integral equations for a system of coaxial axisymmetric interface cracks, including penny-shaped and annular cracks. cracks with Cauchy type kernel. The integral equations are of Cauchy singular type, which are solved by Erdogan’s collocation method for dislocation density on the surface of interfacial crack and the results are used to determine stress intensity factors (SIFs) for axisymmetric interface cracks. Finally, several examples are provided to study the effects of the non-homogeneity constant, orthotropy parameter and thickness of FGM coating on the SIFs for interfacial cracks.. The effects of the non-homogeneity constant, orthotropy parameter and thickness of FGM coating as well as the interaction of multiple interfacial cracks on the SIFs are investigated. The results reveal that the value of the SIFs decreases with increasing the non-homogeneity parameter, orthotropy and thickness of FGM coating. The SIFs for inner tips of annular interface crack are larger than the outer tips. پرونده مقاله

فهرست مقالات Axisymmetric

سکوی نشر دانش

پیوندهای سایت

مراکز مرتبط

پشتیبانی

صفحات رسمی