Islamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Vibration Analysis of Carotid Arteries Conveying Non-Newtonian Blood Flow Surrounding by Tissues693704527015ENA.H Ghorbanpour AraniFaculty of Mechanical Engineering, University of Tehran, Tehran, IranA RastgooFaculty of Mechanical Engineering, University of Tehran, Tehran, IranA. Ghorbanpour AraniFaculty of Mechanical Engineering, University of Kashan, Kashan, Iran ---
Institute of Nanoscience & Nanotechnology, University of Kashan, Kashan, IranR KolahchiFaculty of Mechanical Engineering, University of Kashan, Kashan, IranJournal Article20160630The high blood rate that often occurs in arteries may play a role in artery failure and tortuosity which leads to blackouts, transitory ischemic attacks and other diseases. However, vibration and instability analysis of carotid arteries are lacking. The objective of this study is to investigate the vibration and instability of the carotid arteries conveying blood under axial tension with surrounding tissue support. Arteries are modeled as elastic cylindrical vessels based on first order shear deformation theory (FSDT) within an elastic substrate. The elastic medium is simulated with visco-Pasternak foundation. The blood flow in carotid artery is modeled with non-Newtonian fluid based on Carreau, power law and Casson models. Applying energy method, Hamilton principle and differential quadrature method (DQM), the frequency, critical blood velocity and transverse displacement of the carotid arteries are obtained. It can be seen that increasing the tissue stiffness would delay critical blood velocity. The current model provides a powerful tool for further experimental investigation arteries tortuosity. In addition, the dimensionless transverse displacement predicted by Newtonian model is lower than that of non-Newtonian models.
http://jsm.iau-arak.ac.ir/article_527015_c48faa4a52f8b0979b0a1f9ab176d851.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Mechanical Stresses in a Linear Plastic FGM Hollow Cylinder Due to Non-Axisymmetric Loads705718527016ENM ShokouhfarSouth Tehran Branch, Islamic Azad University,Tehran, IranM JabbariSouth Tehran Branch, Islamic Azad University,Tehran, IranJournal Article20160703In this paper, an analytical solution for computing the linear plastic stresses and critical pressure in a FGM hollow cylinder under the internal pressure due to non-Axisymmetric Loads is developed. It has been assumed that the modulus of elasticity was varying through thickness of the FGM material according to a power law relationship. The Poisson's ratio was considered constant throughout the thickness. The general form of mechanical boundary conditions is considered on the inside surfaces. In the analysis presented here the effect of non-homogeneity in FGM cylinder was implemented by choosing a dimensionless parameter, named m, which could be assigned an arbitrary value affecting the stresses in the cylinder. Distribution of stresses in radial, circumferential and shear directions for FGM cylinders under the influence of internal pressure were obtained. Graphs of variations of stress versus radius of the cylinder were plotted. The direct method is used to solve the Navier equations. http://jsm.iau-arak.ac.ir/article_527016_0d08eef07a5802a42c17e525cb2c8a3e.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Finite Difference Method for Biaxial and Uniaxial Buckling of Rectangular Silver Nanoplates Resting on Elastic Foundations in Thermal Environments Based on Surface Stress and Nonlocal Elasticity Theories719733527017ENM karimiDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran0000-0002-8745-0818A.R ShahidiDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IranJournal Article20160705In this article, surface stress and nonlocal effects on the biaxial and uniaxial buckling of rectangular silver nanoplates embedded in elastic media are investigated using finite difference method (FDM). The uniform temperature change is utilized to study thermal effect. The surface energy effects are taken into account using the Gurtin-Murdoch’s theory. Using the principle of virtual work, the governing equations considering small scale for both nanoplate bulk and surface are derived. The influence of important parameters including, the Winkler and shear elastic moduli, boundary conditions, in-plane biaxial and uniaxial loads, and width-to-length aspect ratio, on the surface stress effects are also studied. The finite difference method, uniaxial buckling, nonlocal effect for both nanoplate bulk and surface, silver material properties, and below-mentioned results are the novelty of this investigation. Results show that the effects of surface elastic modulus on the uniaxial buckling are more noticeable than that of biaxial buckling, but the influences of surface residual stress on the biaxial buckling are more pronounced than that of uniaxial buckling.http://jsm.iau-arak.ac.ir/article_527017_a7376dd3da2ebedf9a4fa07beeedb04f.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Finite Element Analysis of Reinforced RC Bracket Using CFRP Plates734743527018ENA RafatiDepartment of Civil, Dezful Branch, Islamic Azad university, Dezful, IranS.V RazaviDepartment of Civil Engineering, Jundi-shapor University of Technology, Dezful, IranJournal Article20160708CFRP composites have unique application qualities such as high resistance and durability to environmental conditions, having relatively low weight and easy to install in strengthening concrete structure elements. The brackets should be strengthen sufficiently if they are not calculated and implemented well. Application of the CFRP is one of the methods for such purposes. The study involves using five different configurations of CFRP sheets as a means of strengthening bracket, using finite element and non-linear dynamic analysis method within the ABAQUS software. Comparative analysis results of non-strengthened bracket model, show a 24.06% increase in the load-carrying capacity of strengthened models using the CFRP compared with the initial model (without CFRP). Results further show an increase of 24.96% of energy absorption in the strengthened models compared with the non-strengthened model.http://jsm.iau-arak.ac.ir/article_527018_bf08f89e5c1cdbfed1ea4e3166fa632c.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Ductile Failure and Safety Optimization of Gas Pipeline744755527020ENP ZamaniDepartment of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, IranA JaamialahmadiDepartment of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, IranM ShariatiDepartment of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20160711Safety and failure in gas pipelines are very important in gas and petroleum industry. For this reason, it is important to study the effect of different parameters in order to reach the maximum safety in design and application. In this paper, a three dimensional finite element analysis is carried out to study the effect of crack length, crack depth, crack position, internal pressure and pipe thickness on failure mode and safety of API X65 gas pipe. Four levels are considered for each parameter and finite element simulations are carried out by using design of experiments (DOE). Then, multi-objective Taguchi method is conducted in order to minimize x and y coordinates of Failure Assessment Diagram (FAD). So, desired levels that minimize the coordinates and rises the possibility of safety are derived for each parameter. The variation in FAD coordinates according to the changes in each parameter are also found. Finally, comparisons between the optimum design and all other experiments and simulations have shown a good safety situation. It is also concluded that the more design parameters close to optimum levels, the better safety condition will occur in FAD. A verification study is performed on the safety of longitudinal semi-elliptical crack and the results has shown a good agreement between numerical and experimental results.http://jsm.iau-arak.ac.ir/article_527020_1e56477cc91db6ab1eb58f63daa49494.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220On the Stability of an Electrostatically-Actuated Functionally Graded Magneto-Electro-Elastic Micro-Beams Under Magneto-Electric Conditions756772527021ENA AmiriMechanical Engineering Department, Urmia University, Urmia, IranG RezazadehMechanical Engineering Department, Urmia University, Urmia, IranR ShabaniMechanical Engineering Department, Urmia University, Urmia, IranA KhanchehgardanMechanical Engineering Department, Urmia University, Urmia, IranJournal Article20160715In this paper, the stability of a functionally graded magneto-electro-elastic (FG-MEE) micro-beam under actuation of electrostatic pressure is studied. For this purpose Euler-Bernoulli beam theory and constitutive relations for magneto-electro-elastic (MEE) materials have been used. We have supposed that material properties vary exponentially along the thickness direction of the micro-beam. Governing motion equations of the micro-beam are derived by using of Hamilton’s principle. Maxwell’s equation and magneto-electric boundary conditions are used in order to determine and formulate magnetic and electric potentials distribution along the thickness direction of the micro-beam. By using of magneto-electric potential distribution, effective axial forces induced by external magneto-electric potential are formulated and then the governing motion equation of the micro-beam under electrostatic actuation is obtained. A Galerkin-based step by step linearization method (SSLM) has been used for static analysis. For dynamic analysis, the Galerkin reduced order model has been used. Static pull-in instability for 5 types of MEE micro-beam with different gradient indexes has been investigated. Furthermore, the effects of external magneto-electric potential on the static and dynamic stability of the micro-beam are discussed in detail.http://jsm.iau-arak.ac.ir/article_527021_e42e9d7e1e75073ae398943f8250c05d.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Analyzing Frequency of Conical (∆ shaped) Tanks773780527022ENF SaljughiNational Iranian Oil Company (NIOC), IranJournal Article20160718A finite element analysis is presented for sloshing and impulsive motion of liquid-filled conical tanks during lateral anti-symmetric excitation. The performed analyses led to the development of a number of charts which can be used to identify the natural frequency, the mode shapes of conical tanks for both fundamental and the cos(θ)-modes of vibration. Conical tank geometry was described with several parameters namely, bottom radius( R<sub>b</sub>) total height of liquid (h), angle of inclination of the tanks(θ<sub>i</sub>), as variables. Numerical result of the free vibration was obtained for the cases of conical tanks with θ<sub>i</sub>=0 and compared with existing experiments and other predicated results, showing a good agreement between the experiment and numerical results.http://jsm.iau-arak.ac.ir/article_527022_09427f7d50e5ad2b87d339083ad3022c.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Dynamic Simulation and Mechanical Properties of Microtubules781787527023ENM MotamediFaculty of Engineering, University of Shahreza, P. O. Box 86149-56841, Isfahan, IranM Mosavi MashhadiDepartment of Mechanical Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, , IranJournal Article20160721This work is conducted to obtain mechanical properties of microtubule. For this aim, interaction energy in alpha-beta, beta-alpha, alpha-alpha, and beta-beta dimers was calculated using the molecular dynamic simulation. Force-distance diagrams for these dimers were obtained using the relation between potential energy and force. Afterwards, instead of each tubulin, one sphere with 55 KDa weight connecting to another tubulin with a nonlinear connection such as nonlinear spring could be considered. The mechanical model of microtubule was used to calculate Young’s modulus based on finite element method. Obtained Young’s modulus has good agreement with previous works. Also, natural frequency of microtubules was calculated based on finite element method.http://jsm.iau-arak.ac.ir/article_527023_f57d0eaef22419b6d6f15827449536a3.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Thermo-Mechanical Vibration Analysis of FG Circular and Annular Nanoplate Based on the Visco-Pasternak Foundation788805527024ENM GoodarziDepartment of Engineering, College of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, IranM MohammadiDepartment of Engineering, College of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, IranM KhooranDepartment of Mechanical Engineering, Shahid Chamran University of Ahvaz, IranF SaadiDepartment of Engineering, College of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, IranJournal Article20160723In this study, the vibration behavior of functional graded (FG) circular and annular nanoplate embedded in a Visco-Pasternak foundation and coupled with temperature change is studied. The effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of FG circular and annular nanoplate. To obtain the vibration frequencies of the FG circular and annular nanoplate, two different size dependent theories are utilized. The material properties of the FGM nanoplates are assumed to vary in the thickness direction and are estimated through the Mori–Tanaka homogenization technique. The FG circular and annular nanoplate is coupled by an enclosing viscoelastic medium which is simulated as a Visco- Pasternak foundation. By using the modified strain gradient theory (MSGT) and the modified couple stress theory (MCST), the governing equation is derived for FG circular and annular nanoplate. The differential quadrature method (DQM) and the Galerkin method (GM) are utilized to solve the governing equation to obtain the frequency vibration of FG circular and annular nanoplate. The results are subsequently compared with valid result reported in the literature. The effects of the size dependent, the in-plane pre-load, the temperature change, the power index parameter, the elastic medium and the boundary conditions on the natural frequencies are investigated. The results show that the size dependent parameter has an increasing effect on the vibration response of circular and annular nanoplate. The temperature change also play an important role in the mechanical behavior of the FG circular and annular nanoplate. The present analysis results can be used for the design of the next generation of nanodevices that make use of the thermal vibration properties of the nanoplatehttp://jsm.iau-arak.ac.ir/article_527024_c73ec8e3fa8e3b28dd54dbd53891d503.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Effects of Gravitational and Hydrostatic Initial Stress on a Two-Temperature Fiber-Reinforced Thermoelastic Medium for Three-Phase-Lag806822527027ENS.M SaidDepartment of Mathematics, Faculty of Science and Arts, Al-mithnab, Qassim University, P.O. Box 931, Buridah 51931, Al-mithnab, Kingdom of Saudi ArabiaM.I.A OthmanDepartment of Mathematics, Faculty of Science, Taif University 888, Saudi ArabiaJournal Article20160726The three-phase-lag model and Green–Naghdi theory without energy dissipation are employed to study the deformation of a two-temperature fiber-reinforced medium with an internal heat source that is moving with a constant speed under a hydrostatic initial stress and the gravity field. The modulus of the elasticity is given as a linear function of the reference temperature. The exact expressions for the displacement components, force stresses, thermal temperature and conductive temperature are obtained by using normal mode analysis. The variations of the considered variables with the horizontal distance are illustrated graphically. A comparison is made with the results of the two theories for two different values of a hydrostatic initial stress. Comparisons are also made with the results of the two theories in the absence and presence of the gravity field as well as the linear temperature coefficient.http://jsm.iau-arak.ac.ir/article_527027_f18037c505dbccc9f4f9597552c60e9b.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Coupled Vibration of Partially Fluid-Filled Laminated Composite Cylindrical Shells823839527091ENM.R SavizMechanical Engineering Department, Azarbaijan Shahid Madani University, Tabriz, IranJournal Article20160728In this study, the free vibration of partially fluid-filled laminated composite circular cylindrical shell with arbitrary boundary conditions has been investigated by using Rayleigh-Ritz method. The analysis has been carried out with strain-displacement relations based on Love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. After determining the kinetic and potential energies of fluid filled laminated composite shell, the eigenvalue problem has been obtained by means of Rayleigh-Ritz method. To demonstrate the validity and accuracy of the results, comparison has been made with the results of similar works for the empty and partially fluid-filled shells. Finally, an extensive parameter study on a typical composite tank is accomplished and some conclusions are drawn.http://jsm.iau-arak.ac.ir/article_527091_174e5268b81e402d6be8243be9202e50.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Thermomechanical Interactions Due to Hall Current in Transversely Isotropic Thermoelastic with and Without Energy Dissipation with Two Temperatures and Rotation840858527092ENR KumarDepartment of Mathematics, Kurukshetra University , Kurukshetra, Haryana, IndiaN SharmaDepartment of Mathematics, MM University, Mullana, Ambala, Haryana, IndiaP LataDepartment of Basic and Applied Sciences, Punjabi University, Patiala, Punjab, IndiaJournal Article20160730The present paper is concerned with the investigation of disturbances in a homogeneous transversely isotropic thermoelastic rotating medium with two temperatures, in the presence of the combined effects of Hall currents and magnetic field due to thermomechanical sources. The formulation is applied to the thermoelasticity theories developed by Green-Naghdi Theories of Type-II and Type-III. Laplace and Fourier transform technique is applied to solve the problem. As an application, the bounding surface is subjected to concentrated and distributed sources (mechanical and thermal sources). The analytical expressions of displacement, stress components, temperature change and current density components are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show a comparison of effect of Hall current on the two theories GN-II and GN-III on resulting quantities. Some special cases are also deduced from the present investigation.http://jsm.iau-arak.ac.ir/article_527092_c4ab8ccbce3739e0ace4c7d6b33132e2.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Non-Local Thermo-Elastic Buckling Analysis of Multi-Layer Annular/Circular Nano-Plates Based on First and Third Order Shear Deformation Theories Using DQ Method859874527096ENSh DastjerdiDepartment of Mechanical Engineering, Shahrood Branch, Islamic Azad University, Shahrood, IranM JabbarzadehDepartment of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, IranJournal Article20160801In present study, thermo-elastic buckling analysis of multi-layer orthotropic annular/circular graphene sheets is investigated based on Eringen’s theory. The moderately thick and also thick nano-plates are considered. Using the non-local first and third order shear deformation theories, the governing equations are derived. The van der Waals interaction between the layers is simulated for multi-layer sheets. The stability governing equations are obtained according to the adjacent equilibrium estate method. The constitutive equations are solved by applying the differential quadrature method (DQM). Applying the differential quadrature method, the ordinary differential equations are transformed to algebraic equations. Then, the critical temperature is obtained. Since there is not any research in thermo-elastic buckling analysis of multi-layer graphene sheets, the results are validated with available single layer articles. The effects of non-local parameter, the values of van der Waals interaction between the layers, third to first order shear deformation theory analyses, non-local to local analyses, different values of Winkler and Pasternak elastic foundation and analysis of bi-layer and triple layer sheets are investigated. It is concluded that the critical temperature increases and tends to a constant value along the rise of van der Waals interaction between the layers.http://jsm.iau-arak.ac.ir/article_527096_1714adc86fb1958d7fab51cf8e705d7c.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Lateral Vibrations of Single-Layered Graphene Sheets Using Doublet Mechanics875894527098ENA Fatahi-VajariDepartment of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranA. ImamDepartment of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranJournal Article20160801This paper investigates the lateral vibration of single-layered graphene sheets based on a new theory called doublet mechanics with a length scale parameter. After a brief reviewing of doublet mechanics fundamentals, a sixth order partial differential equation that governs the lateral vibration of single-layered graphene sheets is derived. Using doublet mechanics, the relation between natural frequency and length scale parameter is obtained in the lateral mode of vibration for single-layered graphene. It is shown that length scale parameter plays a significant role in the lateral vibration behavior of single-layered graphene sheets. Such effect decreases the natural frequency compared to the predictions of the classical continuum mechanics models. However with increasing the length of the plate, the effect of scale parameter on the natural frequency decreases. For validating the results of this method, the results obtained herein are compared with the existing nonlocal and molecular dynamics results and good agreement with the latter is observed.http://jsm.iau-arak.ac.ir/article_527098_ed563df59152312ad44d003a06d4c7f1.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Free and Forced Transverse Vibration Analysis of Moderately Thick Orthotropic Plates Using Spectral Finite Element Method895915527099ENM.R BahramiCivil Engineering Department, Yasouj University, Yasouj, IranS HatamiCivil Engineering Department, Yasouj University, Yasouj, IranJournal Article20160806In the present study, a spectral finite element method is developed for free and forced transverse vibration of Levy-type moderately thick rectangular orthotropic plates based on first-order shear deformation theory. Levy solution assumption was used to convert the two-dimensional problem into a one-dimensional problem. In the first step, the governing out-of-plane differential equations are transformed from time domain into frequency domain by discrete Fourier transform theory. Then, the spectral stiffness matrix is formulated, using frequency-dependent dynamic shape functions which are obtained from the exact solution of the governing differential equations. An efficient numerical algorithm, using drawing method is used to extract the natural frequencies. The frequency domain dynamic responses are obtained from solution of the spectral element equation. Also, the time domain dynamic responses are derived by using inverse discrete Fourier transform algorithm. The accuracy and excellent performance of the spectral finite element method is then compared with the results obtained from closed form solution methods in previous studies. Finally, comprehensive results for out-of-plane natural frequencies and transverse displacement of the moderately thick rectangular plates with six different combinations of boundary conditions are presented. These results can serve as a benchmark to compare the accuracy and precision of the numerical methods used.http://jsm.iau-arak.ac.ir/article_527099_8c1292937734d13b00958565d6ab6921.pdfIslamic Azad University Arak BranchJournal of Solid Mechanics2008-35058420161220Calculation of Collision Speed Corresponded to Maximum Penetration Using Hydrodynamic Theory916922527100ENA.R NezamabadiDepartment of Mechanical Engineering, Islamic Azad University, Arak Branch, Arak, IranJournal Article20160810One of the most valid and efficient models of long rod projectile penetration in homogeneous targets is Tate and Alekseevskii’s (A&t) model. Based on Tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. The proposed collision speed-penetration depth diagrams are developed using Tate’s model. In this way, various collision speed-penetration depth diagrams for different projectile dynamic resistances and targets are calculated and the optimum speed envelope is derived. According to Tate’s diagrams, the increase of collision speed is not followed by the increase of penetration depth; instead, it causes erosion phenomenon to happen. The comparison of the resulted optimum penetration speeds and the available data confirms the findings. Speed and rigidity both have a positive impact on the increase of penetration depth. With the increase of speed, the erosion issue finds a higher significance due to the increase of pressure on the projectile tip. Therefore, higher speed and erosion are opposed to each other; for the case of Y>R, there are some maximum points which indicate the optimum reciprocity of the two mentioned factors to obtain a maximum penetration depth. In the present research, an equation is developed indicating the optimum speeds resulting in the maximum penetration rate in the case of Y>R. For the reciprocity of speed and erosion, the target resistance against an erosive projectile should be 4 to 5 fold higher than the same target resistance against a rigid projectile penetration. [1]http://jsm.iau-arak.ac.ir/article_527100_6139e27dad585b17c7ca7c5276e75fec.pdf