eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
1
11
520686
Torsion of Poroelastic Shaft with Hollow Elliptical Section
M Jabbari
mohsen.jabbari@gmail.com
1
M.F Khansanami
2
Department of Mechanical Engineering, Islamic Azad University, South Tehran Branch, Iran
Department of Mechanical Engineering, Islamic Azad University, South Tehran Branch, Iran
In this paper torsion of hollow Poroelastic shaft with Elliptical section is developed. Using the boundary equation scheme. It looks for a stress function where satisfied Poisson equation and vanishes on boundary. It also analyzed stress function and warping displacement for the hollow elliptical section in Poroelastic shaft. At the end, the result of elastic and poroelastic shaft in warping displacement and stress function is compared.
http://jsm.iau-arak.ac.ir/article_520686_943874108dbda5d45f258afe678dddf6.pdf
Torsion
Stress function
Warping
Poroelastic
Inhomogeneous
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
12
30
520687
Free Vibration of Sandwich Panels with Smart Magneto-Rheological Layers and Flexible Cores
G Payganeh
g.payganeh@srttu.edu
1
K Malekzadeh
2
H Malek-Mohammadi
3
School of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Tehran, Iran
Structural Analysis and Simulation Department,Space Research Institute, Malek Ashtar University of Technology
School of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Tehran, Iran
This is the first study on the free vibrational behavior of sandwich panels with flexible core in the presence of smart sheets of oil which is capable of the excitation of magnetic field. In order to model the core, the improved high order theory of sandwich sheets was used by a polynomial with unknown coefficients first degree shear theory was used for the sheets. The derived equations based on Hamilton principle with simple support boundary condition for upper and lower sheets were solved using Navier technique. Accuracy and precision of the theory were investigated by comparing the results of this study with those of analytical and numerical works. In the conclusion section, effect of the intensity of magnetic field and other physical parameters including ratio of sheet's length to width, ratio of sheet's length to thickness, ratio of core thickness to sheet's overall thickness, and ratio of oil layer thickness to sheet's overall thickness on natural frequency was investigated.
http://jsm.iau-arak.ac.ir/article_520687_8c297754ec33c2a5335e94c67e838184.pdf
Sandwich plates
Flexible cores
Free vibration
Improved high order theory
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
31
44
520688
Closed Form Solution for Electro-Magneto-Thermo-Elastic Behaviour of Double-Layered Composite Cylinder
A Loghman
aloghman@kashanu.ac.ir
1
H Parsa
2
Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Islamic Republic of Iran
Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Islamic Republic of Iran
Electro-magneto-thermo-elastic response of a thick double-layered cylinder made from a homogeneous interlayer and a functionally graded piezoelectric material (FGPM) outer layer is investigated. Material properties of the FGPM layer vary along radius based on the power law distribution. The vessel is subjected to an internal pressure, an induced electric potential, a uniform magnetic field and a temperature gradient. Stresses and radial displacement are studied for different material in-homogeneity parameters in the FGPM layer. It has been shown that the material in-homogeneity parameters significantly affect the stress distribution in both layers. Therefore by selecting a suitable material parameter one can control stress distribution in both homogeneous and FGPM layers. It has been found that under electro-magneto-thermo-mechanical loading minimum effective stress can be achieved by selecting in the FGPM layer.
http://jsm.iau-arak.ac.ir/article_520688_bf9c70220e1756cbd8e91a3ab6fd11ad.pdf
Closed form solution
Electromagnetothermoelastic
Double-walled cylinder
Homogeneous interlayer
FGPM outer layer
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
45
57
520689
Dynamic Stability of Laminated Composite Plates with an External Smart Damper
M Hoseinzadeh
1
J Rezaeepazhand
jrezaeep@um.ac.ir
2
Department of Mechanical Engineering , Ferdowsi University of Mashhad , Mashhad, Iran
Department of Mechanical Engineering , Ferdowsi University of Mashhad , Mashhad, Iran
The dynamic stability of a composite plate with external electrorheological (ER) damper subjected to an axial periodic load is investigated. Electrorheological fluids are a class of smart materials, which exhibit reversible changes in mechanical properties when subjected to an electric field. As a result, the dynamic behavior of the structure is changed. The ER damper is used for suppressing the vibrations and improving the stability of the system. The Bingham plastic model is employed to express the behavior of the ER fluid. The finite element model of the structure is developed and constant acceleration average method is used to obtain the response of the system. Effect of different parameters such as the electric field, the orientation of the ER damper, the initial gap between the two electrodes of the ER damper and the stacking sequences of the plate on the first instability boundaries of the composite plate are investigated.
http://jsm.iau-arak.ac.ir/article_520689_a47e9dd1896a9a4d7289a46ea7dcdf49.pdf
Laminated composite
Dynamic buckling
FEA
Smart structures
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
58
77
520690
Reflection and Transmission at the Boundary of Two Couple Stress Generalized Thermoelastic Solids
R Kumar
rajneesh_kuk@rediffmail.com
1
K Kumar
2
R.C Nautiyal
3
Department of Mathematics, Kurukshetra University, Kurukshetra, Haryana, 136119, India
Department of Mathematics, DeenBandhu Chhotu Ram University of Science and Technology, Sonipat, Haryana, 131001, India
Department of Mathematics, DeenBandhu Chhotu Ram University of Science and Technology, Sonipat, Haryana, 131001, India
In this paper the reflection and transmission at a plane interface between two different couple stress generalized thermoelastic solid half spaces in context of Loard-Shulman(LS)[1967] and Green-Lindsay(GL)[1972] theories in welded contact has been investigated. Amplitude ratios of various reflected and transmitted waves are obtained due to incidence of a set of coupled longitudinal waves and coupled transverse waves. It is found that the amplitude ratios of various reflected and transmitted waves are functions of angle of incidence, frequency and are affected by the couple stress properties of the media. Some special cases are deduced from the present formulation.
http://jsm.iau-arak.ac.ir/article_520690_02a6c79fbb67128e698ac2b618c02e57.pdf
Couple stress thermoelastic solid
Longitudinal wave
Transverse wave
Reflection
Transmission
Amplitude ratios
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
78
92
520691
Dynamic Response of an Axially Moving Viscoelastic Timoshenko Beam
H Seddighi
1
H.R Eipakchi
hamidre_2000@vatanmail.ir
2
School of Mechanical Engineering, University of Shahrood , Shahrood , Islamic Republic of Iran
School of Mechanical Engineering, University of Shahrood , Shahrood , Islamic Republic of Iran
In this paper, the dynamic response of an axially moving viscoelastic beam with simple supports is calculated analytically based on Timoshenko theory. The beam material property is separated to shear and bulk effects. It is assumed that the beam is incompressible in bulk and viscoelastic in shear, which obeys the standard linear model with the material time derivative. The axial speed is characterized by a simple harmonic variation about a constant mean speed. The method of multiple scales with the solvability condition is applied to dimensionless form of governing equations in modal analysis and principal parametric resonance. By a parametric study, the effects of velocity, geometry and viscoelastic parameters are investigated on the response.
http://jsm.iau-arak.ac.ir/article_520691_f045e1e5df6f7bd42eeb1fcfcf5d9810.pdf
Viscoelastic
Axially moving beam
Perturbation
Dynamic Response
Timoshenko theory
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
93
103
520692
A Simple Finite Element Procedure for Free Vibration and Buckling Analysis of Cracked Beam-Like Structures
M.R Shirazizadeh
mshirazizadeh@yahoo.com
1
H Shahverdi
2
A Imam
3
Department of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Aerospace Engineering and Center of Excellence in Computational Aerospace, Amirkabir University of Technology, 424 Hafez Avenue, Tehran 15875-4413, Iran
Department of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
In this study, a novel and very simple finite element procedure is presented for free vibration and buckling analysis of slim beam-like structures damaged by edge cracks. A cracked region of a beam is modeled using a very short element with reduced second moment of area (<em>I</em>). For computing reduced <em>I</em> in a cracked region, the elementary theory of bending of beams and local flexibility approach are used. The method is able to model cracked beam-columns by using ordinary beam elements. Therefore, it is possible to solve these problems with much less computational costs compared to 2D and 3D standard FE models. Numerical examples are offered to demonstrate the efficiency and effectiveness of the presented method.
http://jsm.iau-arak.ac.ir/article_520692_1985a372b0f3c19f717ea945157417fe.pdf
Cracked beam
Modal Analysis
Buckling load
F.E.M
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
104
115
520694
A New Numerical Procedure for Determination of Effective Elastic Constants in Unidirectional Composite Plates
S Daryazadeh
1
L Lvov Gennadiy
2
M Tajdari
m.tajdari@srbiau.ac.ir
3
National Technical University , Kharkov Polytechnic Institute, Ukraine, Kharkov
National Technical University , Kharkov Polytechnic Institute, Ukraine, Kharkov
Department of Mechanical Engineering, Islamic Azad University, Arak Branch, Arak, Iran
In this paper a composite plate with similar unidirectional fibers is considered. Assuming orthotropic structure, theory of elasticity is used for investigating the stress concentration. Also, complex variable functions are utilized for solving the plane stress problems. Then the effective characteristics of this plate are studied numerically by using ANSYS software. In this research a volume element of fibers in square array is considered. In order to investigate the numerical finite element modeling, the modeling of a quarter unit cell is considered. For determining the elasticity coefficients, stress analysis is performed for considered volume with noting to boundary conditions. Effective elasticity and mechanical properties of composite which polymer epoxy is considered as its matrix, are determined theoretically and also by the proposed method in this paper with finite element method. Finally, the variations of mechanical properties with respect to fiber-volume fraction are studied.
http://jsm.iau-arak.ac.ir/article_520694_d89f5b90ec8b8d043a77f25b47e4ff34.pdf
Composite plate
Unidirectional fibers
Effective elastic constants
Orthotropic plate
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
116
129
520695
Numerical and Experimental Study of Buckling of Rectangular Steel Plates with a Cutout
M Shariati
mshariati44@um.ac.ir
1
Y Faradjian
2
H Mehrabi
3
Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
Steel plates are used in various structures, such as the structures of the deck and body of ships, bridges, and aerospace industry. In this study, we investigate the buckling and post-buckling behavior of rectangular steel plates having circular cutouts with two boundary conditions: first, clamped supports at upper and lower ends and free supports at other edges; second, clamped supports at upper and lower ends and simply supports at other edges, using finite element method (by ABAQUS software) and experimental tests(by an INSTRON servo hydraulic machine). In this research, in addition to the aspect ratio, the effect of changing the location of the cutout on the buckling analysis is investigated. The results of both numerical and experimental analyses are compared and showing a very good agreement between them.
http://jsm.iau-arak.ac.ir/article_520695_c6afb39f9d7ce16b28798f300e125040.pdf
Buckling
Steel plates
Cutout
Experimental analysis
FEM
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
130
151
520696
Dynamic Analysis of Offshore Wind Turbine Towers with Fixed Monopile Platform Using the Transfer Matrix Method
M Feyzollahzadeh
1
M.J Mahmoodi
mj_mahmoudi@sbu.ac.ir
2
Faculty of Mechanical and Energy Engineering, Shahid Beheshti University, Tehran, Iran
Faculty of Mechanical and Energy Engineering, Shahid Beheshti University, Tehran, Iran
In this paper, an analytical method for vibrations analysis of offshore wind turbine towers with fixed monopile platform is presented. For this purpose, various and the most general models including CS, DS and AF models are used for modeling of wind turbine foundation and axial force is modeled as a variable force as well. The required equations for determination of wind turbine tower response excited by the Morrison force are derived based on Airy wave theory. The transfer matrix is derived for each element of the tower using Euler-Bernoulli’s beam differential equation and the global transfer matrix is obtained considering boundary conditions of the tower and constructing the point matrix. The effective wave force is intended in several case studies and Persian Gulf Environmental conditions are examined for the installation of wind farms. Finally, the obtained results by the transfer matrix method are compared with the results of the finite elements method and experimental data which show good agreement in spite of low computational cost.
http://jsm.iau-arak.ac.ir/article_520696_d3757687ae75b5158b07a6ad0568030c.pdf
Offshore wind turbine tower
Transfer matrix method
Natural Frequencies
Foundation models
Morrison wave force
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
152
167
520697
An Exact Solution for Kelvin-Voigt Model Classic Coupled Thermo Viscoelasticity in Spherical Coordinates
S Bagheri
1
M Jabbari
mohsen.jabbari@gmail.com
2
Mechanical Engineering Department, Islamic Azad University, South Tehran Branch, Tehran, Iran
Mechanical Engineering Department, Islamic Azad University, South Tehran Branch, Tehran, Iran
In this paper, the classic Kelvin-Voigt model coupled thermo-viscoelasticity model of hollow and solid spheres under radial symmetric loading condition is considered. A full analytical method is used and an exact unique solution of the classic coupled equations is presented. The thermal and mechanical boundary conditions, the body force, and the heat source are considered in the most general forms and where no limiting assumption is used. This generality allows simulate varieties of applicable problems. At the end, numerical results are presented and compared with classic theory of thermoelasticity.
http://jsm.iau-arak.ac.ir/article_520697_98ab83d19ee7a3236071d8a863249153.pdf
Coupled thermo viscoelasticity
Hollow sphere
Exact solution
Kelvin-Voigt method
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
168
174
520698
Frequency Aanalysis of Annular Plates Having a Small Core and Guided Edges at Both Inner and Outer Boundaries
L.B Rao
bhaskarbabu_20@yahoo.com
1
C.K Rao
2
School of Mechanical and Building Sciences, VIT University, Chennai Campus, Vandalur-Kelambakkam Road, Chennai-600127, Tamil Nadu, India
Nalla Narsimha Reddy Engineering College, Korremula 'X' Road, Chowdariguda (V), Ghatkesar (M), Ranga Reddy (dt) - 500088, Telangana State, India
This paper deals with frequency analysis of annular plates having a small core and guided edges at both inner and outer boundaries. Using classical plate theory the governing differential equation of motion for the annular plate having a small core is derived and solved for the case of plate being guided at inner and outer edge boundaries. The fundamental frequencies for the first six modes of annular plate vibrations are computed for different materials and varying values of the radius parameter. The fundamental frequencies thus obtained may be classified into to axisymmetric and/or non-axisymmetric modes of vibration. The exact values of fundamental frequencies presented in this paper clearly show that no mode switching takes place for the case of annular plates with guided edges. The results presented in this paper will be of use in design and also serve as benchmark values to enable the researchers to validate their results obtained using numerical methods such as differential quadrature or finite element methods.
http://jsm.iau-arak.ac.ir/article_520698_151f1b8dd6019c4a4bab7e123553aeb5.pdf
Annular Plate
vibrations
Guided edge
Mode switching
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
175
183
520699
Consolidation Around a Heat Source in an Isotropic Fully Saturated Rock with Porous Structure in Quasi-Static State
N Das Gupta
gangulynilanjana@rediffmail.com
1
N.C Das
2
Department of Mathematics, Jadavpur University, Kolkata, India
Department of Mathematics, Brainware Group of Institutions, Barasat, India
The titled problem of coupled thermoelasticity for porous structure has been solved with an instantaneous heat source acting on a plane area in an unbounded medium. The basic equations of thermoelasticity, after being converted into a one-dimensional form, have been written in the form of a vector-matrix differential equation and solved by the eigenvalue approach for the field variables in the Laplace transform domain in closed form. The deformation, temperature and pore pressure have been determined for the space time domain by numerical inversion from the Laplace transform domain. Finally the results are analyzed by depicting several graphs for the field variables.
http://jsm.iau-arak.ac.ir/article_520699_3421e738ab5f5c0e8a0db0c27d818d6e.pdf
Consolidation
Porous
Isotropic
Thermoelasticity
Quasi-Static
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
184
203
520700
Generalized Differential Quadrature Method for Vibration Analysis of Cantilever Trapezoidal FG Thick Plate
K Torabi
kvntrb@kashanu.ac.ir
1
H Afshari
2
Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
This paper presents a numerical solution for vibration analysis of a cantilever trapezoidal thick plate. The material of the plate is considered to be graded through the thickness from a metal surface to a ceramic one according to a power law function. Kinetic and strain energies are derived based on the Reissner-Mindlin theory for thick plates and using Hamilton's principle, the governing equations and boundary conditions are derived in the Cartesian coordinates. A transformation of coordinates is used to convert the equations and boundary conditions from the original coordinate into a new computational coordinates. Generalized differential quadrature method (GDQM) is selected as a strong method and natural frequencies and corresponding modes are derived. The accuracy and convergence of the proposed solution are confirmed using results presented by other authors. Finally, the effect of the power law index, angles and thickness of the plate on the natural frequencies are investigated.
http://jsm.iau-arak.ac.ir/article_520700_e6448139cd449390018d7014c8f285e1.pdf
Generalized differential quadrature method (GDQM)
Vibration analysis
Trapezoidal plate
Functionally graded materials (FGM)
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
204
211
520701
Steady Thermal Stresses in a Thin Rotating Disc of Finitesimal Deformation with Mechanical Load
J Kaur
1
P Thakur
dr_pankajthakur@yahoo.com
2
S.B Singh
3
Department of Mathematics, Punjabi University Patiala, Punjab 147002, India
Department of Mathematics, IEC University Baddi, Solan, Himachal Pradesh 174103, India
Department of Mathematics, Punjabi University Patiala, Punjab 147002, India
Seth’s transition theory is applied to the problems of thickness variation parameter in a thin rotating disc by finite deformation. Neither the yield criterion nor the associated flow rule is assumed here. The results obtained here are applicable to compressible materials. If the additional condition of incompressibility is imposed, then the expression for stresses corresponds to those arising from Tresca yield condition. It has observed that for rotating disc made of compressible material required higher angular speed to yield at the internal surface as compare to disc made of incompressible material and a much higher angular speed is required to yield with the increase in radii ratio. With the introduction of thermal effects, lesser angular speed is required to yield at the internal surface. Thermal effect in the disc increase the value of circumferential stress at the internal surface and radial stresses at the external surface for compressible as compare to incompressible material.
http://jsm.iau-arak.ac.ir/article_520701_5622819ff9faf68953f9a0c8aa27abe1.pdf
Plastic
Transitional
Finitesimal
Stresses
Disc
Load
temperature
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2016-03-30
8
1
212
231
520702
Free Vibration Analysis of Continuously Graded Fiber Reinforced Truncated Conical Shell Via Third-Order Shear Deformation Theory
M.H Yas
yas@razi.ac.ir
1
M Nejati
2
A Asanjarani
3
Mechanical Engineering Department, Razi University, Kermanshah, Iran
Mechanical Engineering Department, Razi University, Kermanshah, Iran
Department of Mechanical Engineering, Islamic Azad University, Arak Branch, Iran
This paper deals with free vibration analysis of continuously graded fiber reinforced (CGFR) truncated conical shell based on third-order shear deformation theory (TSDT), by developing special power-law distributions. The orthotropic (CGFR) truncated conical shell are clamped and simply supported at the both ends. It is assumed to have a smooth variation of fibers volume fraction in the thickness direction. Symmetric and classic volume fraction profiles are examined. The appropriate displacement functions which identically satisfy the axisymmertic conditions are used to simplify the motion equations to a set of coupled ordinary differential equation with variable coefficients, which can be solved by generalized differential quadrature method (GDQM), to obtain the natural frequencies. The fast rate of convergence of the method is observed. To validate the results, comparisons are made with the available solutions for isotropic and CGM isotropic truncated conical shells. The effect of various geometrical parameters on the vibrational behavior of the CGFR truncated conical shell is investigated. This literature mainly contributes to illustrate the impact of the power-law distributions on the vibrarional behavior of orthotropic continuous grading truncated conical shell. This paper is also supposed to present useful results for continuouly graded fibers volume fraction in the thickness direction of a truncated conical shell and comparison with similar discrete laminated composite one.
http://jsm.iau-arak.ac.ir/article_520702_92d9bbc39f3a1902edcc498a7809278c.pdf
Continuously graded fiber reinforced
Special power-law distributions
Truncated conical shell
Free vibration
TSDT