Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering: 4 (1)

Open Access Article

1 - Analysis of chaotic vibration in a hexagonal centrifugal governor system
مصطفی غیور سعید ضیایی راد حبیب رمضان نژاد آزاربنی

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, bifurc More

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. Manuscript profile

Open Access Article

2 - Study on of Foil Rolling With Lubrication Effects
مینا عرب اف محمود سلیمی محسن اصفهانیان

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 mec More

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. Manuscript profile

Open Access Article

3 - Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
محسن فتاحی فاطمه فرهت نیا منصور درویزه

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 equat More

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. Manuscript profile

Open Access Article

4 - Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
حسن مسلمی نائینی مهدی تاجداری سیامک مزدک ولی اله پناهی زاده

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 equat More

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. Manuscript profile

Open Access Article

5 - Stress Analysis of Magneto Thermoelastic and Induction Magnetic Filed in FGM Hallow Sphere
حسن خادمی زاده علی قربان پور آرانی محمد سالاری

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 magneto More

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. Manuscript profile

Open Access Article

6 - Prediction of Surface in Machining by Flat and Spherical Surface Tools
محمد رضا موحدی امیر جدیری فیضی

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-e More

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 Manuscript profile

Open Access Article

7 - Static and Dynamic Analysis of Bus Structure and Chassis of O-457
ابوالفضل محبوبی شاد محسن اصفهانیان

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 More

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. Manuscript profile

Open Access Article

8 - Numerical Study on Effect of Bilinear Pressure Path on Corner Filling in Hydroforming of Tube in Box-Shape Die
محسن لوح موسوی میثم شهبازی

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 bilinea More

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. Manuscript profile

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