Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Analysis of chaotic vibration in a hexagonal centrifugal governor system
1
12
EN
Mostafa
Ghayour
- Assistant Professor, Mechanical Engineering Faculty, Isfahan University of Technology
ghayour@cc.iut.ac.ir
Saeed
Zeiaei Rad
Associate Professor, Mechanical Engineering Faculty, Isfahan University of Technology
Habib Ramezan Nezhad
Ramezan Nezhad
M.Sc., Mechanical Engineering Faculty, Isfahan University of Technology
In this paper, the periodic, quasi periodic and chaotic responses of rotational machines with a hexagonal centrifugal governor are studied. The external disturbance is assumed as a sinusoid effect. By using the forth order Rung-Kutta numerical integration method, bifurcation diagram, largest Lyapunov exponent and Lyapunov dimension are calculated and presented to detect the critical controlling parameter. Having known the critical values, phase portrait, Poincare maps, time history and power spectrum are presented to observe periodic, quasi-periodic and chaotic behaviors of the system. Finally, the system damping is used as a parameter to control chaos. It is shown that by increasing the system damping, the chaotic behavior of the system converts to a periodic motion.
Governor,Chaotic vibration,Lyapunov Exponent,Poincare's Mapping,Power Spectrum
http://jsme.iaukhsh.ac.ir/article_515554.html
http://jsme.iaukhsh.ac.ir/article_515554_4a92ce692345109973e6faeea2446437.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Study on of Foil Rolling With Lubrication Effects
13
22
EN
Mina
Arabof
- M. Sc., Mechanical Engineering Dept. , Isfahan University Of Technology
Mahmoud
Salimi
Professor, Mechanical Engineering Dept. , Isfahan University Of Technology
salimi@cc.iut.ac.ir
Mohsen
Esfahanian
Assistant Professor, Mechanical Engineering Dept. , Isfahan University Of Technology
mesf1964@cc.iut.ac.ir
In cold rolling of thin strips, i.e., foils (Thickness<50µm), it is important to take into account the flattening of the roll surfaces. The displacement of the roll surface is obtained by combining some results from the well-known Hertzian theory of contact mechanics and roll-modeling as a system of springs with different spring constants within contact conjunction. Use of lubricants can reduce rolling force and improve surface properties of the foil. Depending on the lubricant properties and rolling speed, either hydrodynamic lubrication or mixed lubrication regimes can prevail. The present theoretical work is focused upon the influence of the rolling-process parameters like rolling speed, reduction ratio, roll surface roughness and lubricant viscosity on the friction coefficient and film thickness in the roll bite in the mixed lubrication regime. Results show that with increase of viscosity, rolling force decreases and film thickness increases.
Cold Rolling,Foil Rolling,Mixed Lubrication,Slab Method
http://jsme.iaukhsh.ac.ir/article_515555.html
http://jsme.iaukhsh.ac.ir/article_515555_827ce3de5d8fc6db2a3cf54d6b4ecdbb.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
23
34
EN
Mohsen
Fattahi
M.Sc., Islamic Azad University, Khomeinishahr Branch
Fatemeh
Farhatnia
Assistant Professor, Islamic Azad University, Khomeinishahr Branch
farhatnia@iaukhsh.ac.ir
Mansour
Darvizeh
Professor, Guilan University
darvizeh@guilan.ac.ir
In this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set of Eigen value equations resulted. In order to solve this Eigen value problem, a computer program was developed using MATLAB software in a way that the influence of different parameters such as length to width ratio (aspect ratio), the number of layers, the angle of layers arrangement, material of layers, kind of loading and boundary conditions were included. A buckling load factor was calculated for simply supported and clamped supported plates. The results of GDQ method were compared with reported results from Rayleigh – Ritz method and with results from solving the Finite element using ANSYS 8.0 software. The comparison showed the accuracy of obtained result clearly.
Buckling - Orthotropic Plate - Anisotropic - Generalized Differential Quadrature Method
http://jsme.iaukhsh.ac.ir/article_515556.html
http://jsme.iaukhsh.ac.ir/article_515556_c66a1ba57ca56c3ccf0abb2d013d3a02.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
35
48
EN
H.
Moslemi Naein
Associate Professor, Tarbiat Modares University
moslemi@modares.ac.ir
Mehdi
Tajdari
Associate Professor, Malek Ashtar University
tajdari@yahoo.com
Siamak
Mazdak
PhD candidate, Tarbiat Modares University
V.
Panahi Zadeh
PhD candidate, Tarbiat Modares University
In this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set of Eigen value equations resulted. In order to solve this Eigen value problem, a computer program was developed using MATLAB software in a way that the influence of different parameters such as length to width ratio (aspect ratio), the number of layers, the angle of layers arrangement, material of layers, kind of loading and boundary conditions were included. A buckling load factor was calculated for simply supported and clamped supported plates. The results of GDQ method were compared with reported results from Rayleigh – Ritz method and with results from solving the Finite element using ANSYS 8.0 software. The comparison showed the accuracy of obtained result clearly.
Buckling - Orthotropic Plate - Anisotropic - Generalized Differential Quadrature Method
http://jsme.iaukhsh.ac.ir/article_515557.html
http://jsme.iaukhsh.ac.ir/article_515557_159c1cda73e29f6f491c0a64c9ed927c.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Stress Analysis of Magneto Thermoelastic and Induction Magnetic Filed in FGM Hallow Sphere
49
56
EN
Hassan
Khademyzadeh
Assistant Professor, Mechanical Engineering Dept., Isfahan University of Technology
hkhademyza@cc.iut.ac.ir
Ali i
Ghorbanpour Aran
Assistant Professor, Kashan University
Mohammad
Salari
M.Sc., Isfahan University of Technology
In this paper a closed form solution for one-dimensional magnetothermoelastic problem in a functionally graded material (FGM) hollow sphere placed in a uniform magnetic field and temperature field subjected to an internal pressure is obtained using the theory of magnetothermoelasticity. Hyper-geometric functions are employed to solve the governing equation. The material properties through the graded direction are assumed to be nonlinear with an exponential distribution. The nonhomogeneity of the material in the radial directions is assumed to be power-exponential. The temperature, displacement and stress fields and the perturbation of magnetic field vector are determined and compared with those of the homogeneous case. Hence, the effect of inhomogeneity on the stresses and the perturbation of magnetic field vector distributions are demonstrated. The results of this study are applicable for designing optimum FGM hollow spheres.
FGM,Hollow sphere,Magnetothermoelasticity,Perturbation of Magnetic Field Vector
http://jsme.iaukhsh.ac.ir/article_515558.html
http://jsme.iaukhsh.ac.ir/article_515558_18cddcf9de767fe5510312540d41209f.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Prediction of Surface in Machining by Flat and Spherical Surface Tools
57
66
EN
M.R.
Movahhedy
Assouiate Professor, Mechanical Engineering Dept., Sharif University
movahhed@sharif.edu
A.
Jodeiri Feizi
M.Sc., Mechanical Engineering Dept., Sharif University
In this paper, the profile of surfaces machined using end mills with flat and ball end tools in modeled. The real kinematics of the tool motion, the static deflection and the run out of the tool are included in the model. The cutting forces are calculated using a semi-empirical method based on orthogonal to oblique conversion of cutting coefficients. The thickness of the uncut chip is used as the critical parameter affected by the tool run out. Based on the above model, the final profile of the surface is generated and compared with existing experimental results
Milling,Flat and Ball End Tools,Tool Deflection,Surface Profile,Tool run out
http://jsme.iaukhsh.ac.ir/article_515559.html
http://jsme.iaukhsh.ac.ir/article_515559_9b3943bf15206baf1d581fe88fee2bca.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Static and Dynamic Analysis of Bus Structure and Chassis of O-457
67
76
EN
A.
Mahboubi shad
M.Sc., Islamic Azad University, Khomeinishahr Branch
M.
Esfahanian
- Assistant Professor, Mechanical Engineering Dept., Isfahan University of Technology
mesf1964@cc.iut.ac.ir
With due attention to the fact that the local and foreign vehicle industries are changing and modifying the previous designs in order to produce new designs, the components of self-propelled are to be differently analyzed. Static and dynamic analysis is one of them. In this paper, chassis and body of a o-457 bus were studied and analyzed under finite element method (using ANSYS).This process was begun with three dimensional modeling of suspension system, chassis and structure of bus. At first, as an initial stage, a static analysis was performed on the bus to assure the resistance of its chassis. In the next stage, the dynamic analyzed including modal and transient analyses were carried out. In the transient analysis, the symmetric and asymmetric simulations were done in order to test structural resistance and flexibility of the bus.
Finite Element,Chassis and Structure,Static Analysis,Dynamic Analysis
http://jsme.iaukhsh.ac.ir/article_515564.html
http://jsme.iaukhsh.ac.ir/article_515564_62ba2c79f73cd1ac7a1e0e08b2b09862.pdf
Islamic Azad University, Khomeinishahr Branch
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
2008-4927
1
1
2008
03
20
Numerical Study on Effect of Bilinear Pressure Path on Corner Filling in Hydroforming of Tube in Box-Shape Die
77
86
EN
Mohsen
Loh-Mousavi
Assistant professor, Department of Mechanical Engineering, Islamic Azad University, Khomeinishahr Branch
loh-mousavi@iaukhsh.ac.ir
Meisam
Shahbazi
M.Sc. Student, Islamic Azad University, Najaf Abad Branch
Die corner filling is very important in tube hydroforming process. Definition of the internal pressure path is a key factor in improving the corner filling. However, the factors that cause improvement of corner filling are still unclear. In this paper, effect of bilinear pressure path on corner filling in hydroforming of tube in box-shape die is studied using both finite element simulation and experiment. For this pressure path, pressure increases to an initial pressure and then it increases to a final pressure (calibration pressure) linearly. It is shown that, an initial pressure lower than yield pressure of the tube is caused a small wrinkle which is eliminated into the corner of die and thus the corner filling is improved, whereas for other pressure paths with higher initial pressures a round bulging occurred in former stages of deformation, and thus the corner filling of die is deteriorated.
Tube Hydroforming,Bilinear Pressure Path,Finite Element Simulation,Improvement of Die Corner Filling,Box-Shape Die
http://jsme.iaukhsh.ac.ir/article_515565.html
http://jsme.iaukhsh.ac.ir/article_515565_f53d24ebc807a23085f7c93418f763b2.pdf