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cylinders--shapes
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Asymmetric mechanical and thermal stresses in 2D-FGPPMs hollow cylinder
, Article Journal of Thermal Stresses ; Volume 40, Issue 4 , 2017 , Pages 448-469 ; 01495739 (ISSN) ; Firoozbakhsh, K ; Jabbari, M ; SelkGhafari, A ; Sharif University of Technology
Taylor and Francis Ltd
2017
Abstract
The general solution of steady-state asymmetric mechanical and thermal stresses of a hollow thick cylinder made of fluid-saturated functionally graded porous piezoelectric materials based on two-dimensional equations of thermoelasticity is considered. 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 nonhomogeneous system of partial differential Navier equations, using the complex Fourier series and the power law functions method. The material properties are assumed to depend on the radial and circumferential variables and are expressed as power law functions...
Elastic-plastic behavior of sandwich cylindrical shell panels with a flexible core
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 231, Issue 2 , 2017 , Pages 223-241 ; 09544062 (ISSN) ; Fallah, F ; Naghdabadi, R ; Kargarnovin, M. H ; Sharif University of Technology
SAGE Publications Ltd
2017
Abstract
The linear static elastic-plastic behavior of sandwich cylindrical shell panels under a generally distributed loading with thick flexible core is studied. The core modeling is based on high-order theory of sandwich structures in which the in-plane stresses of the core are neglected. The faces are modeled based on Kirchhoff-Love shell theory. The materials of the faces and the core are assumed to be isotropic with linear work hardening behavior. The incremental Prandtl-Reuss plastic flow theory is used in this analysis. Using the principle of virtual displacements, the governing equations are derived and solved for any sort of boundary conditions based on elastic-plastic harmonic differential...
Heat transfer enhancement in annular flow with outer grooved cylinder and rotating inner cylinder: review and experiments
, Article Applied Thermal Engineering ; Volume 120 , 2017 , Pages 257-268 ; 13594311 (ISSN) ; Nakhchi, M. E ; Sharif University of Technology
Abstract
This experimental work is an attempt to identify the most significant parameters influencing heat transfer enhancement in annular flow with outer grooved cylinder and rotating inner cylinder. This type of flow known as Taylor-Couette flow has many industrial applications such as electrical power generators and rotating machineries. A comprehensive review of the previous works on flow regimes, heat transfer and pressure drop in grooved channels is provided. The experiments are conducted based on four different factors including Taylor number, 0
Standard and boundary layer perturbation approaches to predict nonlinear axisymmetric behavior of cylindrical shells
, Article Composite Structures ; Volume 204 , 2018 , Pages 855-881 ; 02638223 (ISSN) ; Taati, E ; Asghari, M ; Reddy, J. N ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The feasibility and performance of standard and boundary layer perturbation techniques in nonlinear analyses of cylindrical shells are investigated. To this end, the nonlinear axisymmetric behavior of short and long functionally graded (FG) cylindrical shells is considered. The nonlinear governing equations of shell theory with first-order approximation and the von Karman nonlinearity are decoupled. This uncoupling makes it possible to present an analytical solution. A new boundary layer perturbation solution is presented by reducing the governing equations to a normalized form of boundary-layer type. Also, the uncoupled governing equations are solved using standard one-, two-, and...
Elastic collapse of thin long cylindrical shells under external pressure
, Article Thin-Walled Structures ; Volume 124 , 2018 , Pages 81-87 ; 02638231 (ISSN) ; Fallah, F ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This paper investigates local elastic buckling of thin long cylindrical shells under external pressure. Based on Donnell's and Sanders’ theories of thin shells and von Karman nonlinearity assumptions, the potential energy is derived. The buckling load and curves of the static equilibrium path are obtained using the Ritz method. The results are validated with the existing ones in the literature. Furthermore, the case where the pressure is perpendicular to the deformed state is compared with a dead loading. It is demonstrated that the former yields a lower critical pressure in both shell theories. © 2017 Elsevier Ltd
An analytical investigation of a 2d-ppms hollow infinite cylinder under Thermo-Electro-Mechanical (TEM) loadings
, Article Journal of Theoretical and Applied Mechanics (Poland) ; Volume 56, Issue 1 , 2018 , Pages 107-122 ; 14292955 (ISSN) ; Firoozbakhsh, K ; Jabbari, M ; Selkghafari, A ; Sharif University of Technology
Polish Society of Theoretical and Allied Mechanics
2018
Abstract
The analytical solution of steady-state asymmetric thermo-electro-mechanical loads of a hollow thick infinite cylinder made of porous piezoelectric materials (2D-PPMs) based on two-dimensional equations of thermoelasticity is considered. 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-exponential law functions method. The material properties are assumed to depend on the radial and circumferential variable and are expressed as power-exponential law...
Effects of after-body on the FIV of a right-angle triangular cylinder in comparison to circular, square, and diamond cross-sections
, Article Ships and Offshore Structures ; 2018 ; 17445302 (ISSN) ; Naeeni, T. O ; Zeinoddini, M ; Seif, M. S ; Dolatshahi Pirooz, M ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
This in-water experimental study deals with the effects of the after-body on the FIV response of round and sharp edge cylinders. Different circular, square, diamond, and right-angle isosceles triangular cross-sections are investigated. The triangular cylinder is examined in four different symmetrical and unsymmetrical configurations with respect to the incident flow. The current towing tank experiments form a basis for the feasibility study of the isosceles triangular cylinders for FIV energy converters. The results indicate that the cylinders with a flat side perpendicular to the flow have a galloping type of response. In contrast, the cylinders with a sharp vertex pointing the flow show a...
Nonlinear transient heat transfer and thermoelastic analysis of thick-walled FGM cylinder with temperature-dependent material properties using hermitian transfinite element
, Article Journal of Mechanical Science and Technology ; Volume 23, Issue 10 , 2009 , Pages 2635-2644 ; 1738494X (ISSN) ; Azadi, M ; Sharif University of Technology
2009
Abstract
Nonlinear transient heat transfer and thermoelastic stress analyses of a thick-walled FGM cylinder with temperature-dependent materials are performed by using the Hermitian transfinite element method. Temperature-dependency of the material properties has not been taken into account in transient thermoelastic analysis, so far. Due to the mentioned dependency, the resulting governing FEM equations of transient heat transfer are highly nonlinear. Furthermore, in all finite element analysis performed so far in the field, Lagrangian elements have been used. To avoid an artificial local heat source at the mutual boundaries of the elements, Hermitian elements are used instead in the present...
Effects of after-body on the FIV of a right-angle triangular cylinder in comparison to circular, square, and diamond cross-sections
, Article Ships and Offshore Structures ; Volume 14, Issue 6 , 2019 , Pages 589-599 ; 17445302 (ISSN) ; Naeeni, S. T. O ; Zeinoddini, M ; Seif, M. S ; Dolatshahi Pirooz, M ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
This in-water experimental study deals with the effects of the after-body on the FIV response of round and sharp edge cylinders. Different circular, square, diamond, and right-angle isosceles triangular cross-sections are investigated. The triangular cylinder is examined in four different symmetrical and unsymmetrical configurations with respect to the incident flow. The current towing tank experiments form a basis for the feasibility study of the isosceles triangular cylinders for FIV energy converters. The results indicate that the cylinders with a flat side perpendicular to the flow have a galloping type of response. In contrast, the cylinders with a sharp vertex pointing the flow show a...
Evaluation of the effects of principal stress direction on shear modulus of unsaturated sand using hollow cylinder apparatus
, Article 7th International Conference on Earthquake Geotechnical Engineering, ICEGE 2019, 17 January 2019 through 20 January 2019 ; 2019 , Pages 3102-3108 ; 9780367143282 (ISBN) ; Ahmadi Givi, F ; Ahmadinezhad, A ; Silvestri F ; Moraci N ; Sharif University of Technology
CRC Press/Balkema
2019
Abstract
Determination of soil shear modulus is one of the most controversial topics in unsaturated soil dynamics. Due to the fact that soils have an anisotropic response, the shear strength and stiffness of geological materials are greatly dependent on the principal stress direction and the intermediate principal stress. In this study, the effects of principal stress direction on shear modulus of unsaturated medium-dense sand have been investigated using cyclic hollow cylinder apparatus. Three series of stress-controlled cyclic tests with different fixed principal stress directions were carried out on the sand sample under different values of suction. Results reveal that shear modulus of unsaturated...
Evaluation of the effects of principal stress direction on shear modulus of unsaturated sand using hollow cylinder apparatus
, Article 7th International Conference on Earthquake Geotechnical Engineering, ICEGE 2019, 17 January 2019 through 20 January 2019 ; Pages 3102-3108 , 2019 ; 9780367143282 (ISBN) ; Ahmadi Givi, F ; Ahmadinezhad, A ; Silvestri F ; Moraci N ; Sharif University of Technology
CRC Press/Balkema
2019
Abstract
Determination of soil shear modulus is one of the most controversial topics in unsaturated soil dynamics. Due to the fact that soils have an anisotropic response, the shear strength and stiffness of geological materials are greatly dependent on the principal stress direction and the intermediate principal stress. In this study, the effects of principal stress direction on shear modulus of unsaturated medium-dense sand have been investigated using cyclic hollow cylinder apparatus. Three series of stress-controlled cyclic tests with different fixed principal stress directions were carried out on the sand sample under different values of suction. Results reveal that shear modulus of unsaturated...
Scaled down models for free vibration analysis of orthogonally stiffened cylindrical shells using similitude theory
, Article 26th Congress of International Council of the Aeronautical Sciences 2008, ICAS 2008, Anchorage, AK, 14 September 2008 through 19 September 2008 ; Volume 2 , 2008 , Pages 3458-3469 ; 9781605607153 (ISBN) ; Jafari, A. A ; Navazi, H. M ; Sharif University of Technology
2008
Abstract
In this paper, the necessary similarity conditions, or scaling laws, for free vibrations of orthogonally stiffened cylindrical shells are developed using similitude theory. The Donnelltype nonlinear strain-displacement relations along with smearing theory are used to model the structure. Then the principle of virtual work is used to analyze the free vibration of the stiffened shell. After nondimensionalizing the derived formulations, the scaling laws are developed, using similitude theory. Then, different examples are solved to validate the scaling laws numerically and experimentally. The obtained results show the effectiveness of the derived formulations
Supersonic flutter prediction of functionally graded cylindrical shells
, Article Composite Structures ; Volume 83, Issue 4 , 2008 , Pages 391-398 ; 02638223 (ISSN) ; Mahmoudkhani, S ; Navazi, H. M ; Sharif University of Technology
2008
Abstract
The supersonic flutter analysis of simply supported FG cylindrical shell for different sets of in-plane boundary conditions is performed. The aeroelastic equations of motion are constructed using Love's shell theory and von Karman-Donnell-type of kinematic nonlinearity coupled with linearized first-order potential (piston) theory. The material properties are assumed to be temperature-dependant and graded across the thickness of the shell according to a simple power law. The temperature distribution is assumed to vary in the thickness direction and is obtained by solving the steady-state heat conduction equation. The pre-stresses due to the thermal and mechanical loadings are obtained by...
Free vibrations of a cord composite laminate thin cylindrical shell on a pasternak foundation
, Article 7th European Conference on Structural Dynamics, EURODYN 2008, 7 July 2008 through 9 July 2008 ; 2008 ; 9780854328826 (ISBN) ; Mamandi, A ; Younesian, D ; Sharif University of Technology
University of Southampton, Institute of Sound Vibration and Research
2008
Abstract
The underground and buried oil and gas pipelines are continuously in contact with earthen soils on the outer surface and compressible fluids on the inner surface. Most these earthen soils can be appropriately represented by a model named Pasternak. Similarly, undersea oil and gas pipelines and tubes of heat exchangers remain in contact with fluids on both sides and also rockets and missiles filled with solid and liquid fuels and shallow shells supported on soft and light filaments in space vehicles, boilers and storage tanks on floor grid work in ships can also be considered as thin circular cylindrical shells on a Pasternak foundation. The basic aim of the presented study is investigation...
Investigation of flow dynamics in porous media using computer simulation
, Article 20th European Simulation and Modelling Conference, ESM 2006, Toulouse, 23 October 2006 through 25 October 2006 ; 2006 , Pages 157-163 ; Zamankhan, P ; Mousavi, S. M ; Pietarinen, K ; Sarkomaa, P ; Sharif University of Technology
EUROSIS
2006
Abstract
The aim of this work is to investigate flow hydrodynamics in porous media. Random non-overlapping spherical particles in a cylindrical geometry were produced as a porous media. Navier-Stokes equations in three-dimensional porous packed bed have been solved and dimensionless pressure drop has been studied for a fluid flow through the porous media at different Reynolds numbers (based on pore permeability and interstitial fluid velocity). The numerical results are in good agreement with those reported by Macdonald (1979) in the range of Reynolds numbers studied. At higher Reynolds numbers turbulent models such as large eddy simulation (LES) and Reynolds stress model (RSM) also have been...
Free vibrations of functionally graded material cylindrical shell closed with two spherical caps
, Article Ships and Offshore Structures ; 2021 ; 17445302 (ISSN) ; Kiani, Y ; Bagheri, N ; Eslami, M. R ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
Free vibration response of a cylindrical shell closed with two hemispherical caps at the ends (hermit capsule) is analysed in this research. It is assumed that the system of joined shell is made from functionally graded materials (FGM). Properties of the shells are assumed to be graded through the thickness. Cylindrical and hemispherical shells are unified in thickness. To capture the effects of through-the-thickness shear deformations and rotary inertias, first order theory of shells is used. Donnell type of kinematic assumptions are adopted to establish the general equations of motion and the associated boundary and continuity conditions with the aid of Hamilton's principle. The resulting...
Low-speed wind energy harvesting from a vibrating cylinder and an obstacle cylinder by flow-induced vibration effect
, Article International Journal of Environmental Science and Technology ; 2021 ; 17351472 (ISSN) ; Shariatzadeh, M. J ; Bijarchi, M. A ; Pournasiri Masouleh, E ; Shafii, M. B ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
An experimental setup has been developed to analyse the impact of cylinder transverse vibration caused by flow-induced vibration, and to improve wind energy harvesting from these vibrations. The setup consists of a cylinder mounted on four springs and is subjected to a uniform and steady flow of wind. In the first part, the effect of mounting a fixed cylinder as an obstacle with different diameters and distances from the downstream vibrating cylinder is investigated. It has been observed that the vibration amplitude on the wake of an unequal-sized obstacle is greatly amplified compared to the case of a single cylinder or an equal-sized cylinder. Numerical simulations has been conducted to...
Numerical study of shock-disturbances interaction in hypersonic inviscid flows with real gas effects using high-order WENO scheme
, Article Computers and Fluids ; Volume 229 , 2021 ; 00457930 (ISSN) ; Hejranfar, K ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In the present study, the shock-disturbances interaction in hypersonic inviscid flows with real gas effects is studied by applying a high-order accurate numerical method with the shock capturing technique. To consider real gas effects, the equilibrium air model is utilized here. The strong conservative form of the unsteady compressible Euler equations in the 2D generalized curvilinear coordinates is formulated and the resulting system of equations for the equilibrium air model is discretized by using the fifth-order finite-difference WENO scheme in space and the explicit third-order TVD Runge–Kutta scheme in time to provide a highly accurate and robust equilibrium airflow solver. The...
Computational intelligence of Levenberg-Marquardt backpropagation neural networks to study the dynamics of expanding/contracting cylinder for Cross magneto-nanofluid flow model
, Article Physica Scripta ; Volume 96, Issue 5 , 2021 ; 00318949 (ISSN) ; Raja, M. A. Z ; Chu, Y. M ; Khan, W. A ; Abbas, S. Z ; Shoaib, M ; Irfan, M ; Sharif University of Technology
IOP Publishing Ltd
2021
Abstract
In the present investigation, design of integrated numerical computing through Levenberg-Marquardt backpropagation neural network (LMBNN) is presented to examine the fluid mechanics problems governing the dynamics of expanding and contracting cylinder for Cross magneto-nanofluid flow (ECCCMNF) model in the presence of time dependent non-uniform magnetic force and permeability of the cylinder. The original system model ECCCMNF in terms of PDEs is converted to nonlinear ODEs by introducing the similarity transformations. Reference dataset of the designed LMBNN methodology is formulated with Adam numerical technique for scenarios of ECCCMNF by variation of thermophoresis temperature ratio...
Dynamic analysis of three-layer cylindrical shells with fractional viscoelastic core and functionally graded face layers
, Article JVC/Journal of Vibration and Control ; Volume 27, Issue 23-24 , 2021 , Pages 2738-2753 ; 10775463 (ISSN) ; Permoon, M. R ; Askarian, A ; Haddadpour, H ; Sharif University of Technology
SAGE Publications Inc
2021
Abstract
Natural frequency and damping behavior of three-layer cylindrical shells with a viscoelastic core layer and functionally graded face layers are studied in this article. Using functionally graded face layers can reduce the stress discontinuity in the face–core interface that causes a catastrophic failure in sandwich structures. The viscoelastic layer is expressed using a fractional-order model, and the functionally graded layers are defined by a power law function. Assuming the classical shell theory for functionally graded layers and the first-order shear deformation theory for the viscoelastic core, equations of motion are derived using Lagrange’s equation and then solved via Rayleigh–Ritz...