Journal of Applied and Computational MechanicsJournal of Applied and Computational Mechanics
http://jacm.scu.ac.ir/
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http://jacm.scu.ac.ir/
Feed provided by Journal of Applied and Computational Mechanics. Click to visit.Multi-boiling Heat Transfer Analysis of a Convective Straight Fin with Temperature-Dependent ...
http://jacm.scu.ac.ir/article_12637_1522.html
In this study, by using the finite volume method, the heat transfer in a convective straight fin with temperature-dependent thermal properties and an internal heat generation under multi-boiling heat transfer modes are analyzed. In this regard, the local heat transfer coefficient is considered to vary within a power-law function of temperature. In the present study, the coexistence of all the boiling modes is taken into consideration. The developed heat transfer models and the corresponding numerical solutions are used to investigate the effects of various thermo-geometric parameters on the thermal performance of the longitudinal rectangular fin. The results shows that the fin temperature distribution, the total heat transfer, and the fin efficiency are significantly affected by the thermo-geometric parameters of the fin and the internal heat generation within the fin. The obtained results can provide a platform for improvements in the design of the fin in the heat transfer equipment.Sat, 30 Sep 2017 20:30:00 +0100Effect of Variable Thermal Expansion Coefficient and Nanofluid Properties on Steady Natural ...
http://jacm.scu.ac.ir/article_12714_1522.html
Steady state natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity and thermal expansion coefficient of Al2O3–water nanofluid. This study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ Φ ≤ 7%), enclosure aspect ratios (0.5 ≤ AR ≤ 2) and temperature differences between the cold and the hot walls (1≤ ∆T≤ 30). The main idea in this study is about the effect of temperature on natural convection pattern of nanofluid by changing nanoparticles concentration. Also, changing thermal expansion coefficient with temperature is considerd in this study which will have significant effects on natural convection and has not been considerd before. In low Rayleigh numbers (Ra= 103) and for cavities with AR≥1, the pattern shown in the average Nusselt number versus volume fraction of nanoparticles diagram deteriorates by increasing ∆T. However, for other cases, increasing ∆T has a positive effect on Nu-Φ diagram. The actual Nuselt number curve depicts that dispersing nanoparticles in base fluid deteriorate natural convection heat transfer which is in a good agreement with experimental works.Sat, 30 Sep 2017 20:30:00 +0100Investigation on the Ultrasonic Tube Hydroforming in the Bulging Process Using Finite Element Method
http://jacm.scu.ac.ir/article_13039_1522.html
In ultrasonic tube hydroforming, the tube is hydro formed while the ultrasonic vibration is applied to the die. Prior studies provide experimental proof that ultrasonic tube hydroforming reduces corner radius, improves lubrication and uniform thickness. Use of ultrasonic vibration can decrease friction at the tube-die interface. Few attempts have been made to analyze the wire drawing while the ultrasonic vibrations were also applied during the processes. A detailed analysis and understanding of the mechanism of improvement is not possible with conventional experimental observation because the ultrasonic vibration processing phenomenon occurs at high speed. Therefore, we attempt to understand the processing mechanism of ultrasonic tube hydroforming using the finite element method (FEM).ABAQUS was used for the FEM. Forming force and formability in tube hydroforming analyzed. From these studies, we quantitatively clarified the mechanism of improved formability characteristics, such as decreased forming load and increasing bulging diameter.Sat, 30 Sep 2017 20:30:00 +0100Flow and Heat Transfer Analysis of the Sodium Alginate Conveying Copper Nanoparticles between ...
http://jacm.scu.ac.ir/article_12773_1522.html
In this study, the steady incompressible flow of a non-Newtonian sodium alginate (SA) fluid conveying copper nanoparticles (Cu) which flow within two vertical parallel plates is investigated by using the homotopy perturbation analytical scheme to solve the coupled nonlinear ordinary equations arising from the mechanics of the fluid. The developed analytical solutions are used to investigate the effect of the fluid flow and heat transfer parameters such as the nanoparticle concentration, the non-Newtonian parameter and the viscosity variation parameter. The obtained analytical results as compared to existing works in literature are in satisfactory agreements. Moreover, the results obtained from the present study can be used for further analysis of the behavior of the sodium alginate in applications such as food processing and chemical and pharmaceutical industries.Sat, 30 Sep 2017 20:30:00 +0100A Method for Determination of the Fundamental Period of Layered Soil Profiles
http://jacm.scu.ac.ir/article_13034_1522.html
In this study, a method is proposed to determine the fundamental period of layered soil profiles. A model considering the layered soil as shear type structure is used. At first, the soil profile is divided into substructures. Then, the stiffness matrices of the substructures considered as the equivalent shear structures are assembled according to the Finite Element Method. Thereinafter, the stiffness matrices of the substructures are transformed into the Modified Finite Element Transfer Matrices, which take part in the literature. Finally, the system matrix is assembled using matrices of the substructures. The proposed method provides reduction in the size of the matrix. Therefore, analysis time is remarkably reduced. At the end of the study, the accuracy of the method is presented by the examples. Consequently, the proposed method offers a practical method for determination of the fundamental period of the soil.Sat, 30 Sep 2017 20:30:00 +0100Bending, Buckling and Vibration of a Functionally Graded Porous Beam Using Finite Elements
http://jacm.scu.ac.ir/article_12817_1522.html
This study presents the effect of porosity on mechanical behaviors of a power distribution functionally graded beam. The Euler-Bernoulli beam is assumed to describe the kinematic relations and constitutive equations. Because of technical problems, particle size shapes and micro-voids are created during the fabrication which should be taken into consideration. Two porosity models are proposed. The first one describes properties in the explicit form as linear functions of the porosity parameter. The second is a modified model which presents porosity and Young’s modulus in an implicit form where the density is assumed as a function of the porosity parameter and Young’s modulus as a ratio of mass with porosity to the mass without porosity. The modified proposed model is more applicable than the first model. The finite element model is developed to solve the problem by using the MATLAB software. Numerical results are presented to show the effects of porosity on mechanical behaviors of functionally graded beams.Sat, 30 Sep 2017 20:30:00 +0100Finite Element Analysis for CFST Columns under Blast Loading
http://jacm.scu.ac.ir/article_12816_1522.html
The columns of frame structures are the key load-bearing components and the exterior columns are susceptible to attack in terrorist blasts. When subjected to blast loads, the columns would suffer a loss of bearing capacity to a certain extent due to the damage imparted which may lead to their collapse and even cause the progressive collapse of the whole structure . The concrete-filled steel columns have been extensively used in the world due to the existence of all suitable characteristics of concrete and steel, more ductility, increasing concrete confinement using the steel wall, the large energy-absorption capacity and the appropriate fire behavior. In the present study, the concrete-filled steel square columns have been simulated under the influence of the blast load using the ABAQUS software. These responses have been compared for scaled distances based on the distance to the source and the weight of the explosive material. As a result, it can be seen that although concrete deformation has been restricted using the steel tube, the inner layer of concrete has been seriously damaged and the column displacement has been decreased by increasing the scaled distance. We also concluded that the concrete-filled steel columns have the high ductility and the blast resistance.Sat, 30 Sep 2017 20:30:00 +0100Modified U-Slot Stacked Micro-Strip Patch Antenna for Ultra-Wideband Applications in S Band, C ...
http://jacm.scu.ac.ir/article_12638_1522.html
The U-slot micro-strip patch antennas were originally developed for bandwidth broadening applications. This study presents a transmission line feed to modify the U-slot stacked rectangular micro-strip patch antenna for Ultra-Wide Band (UWB) communications. The modified antenna has a U-cut loaded with parallel slits and corner slots and is printed on a dielectric substrate of FR4 with relative permittivity (εr) of 4.4, the thickness of 1.59 mm and the tangent loss of 0.025. The results show that the proposed antenna achieves an impedance bandwidth of 11.55 GHz (2.1 – 13.65 GHz) with the return loss < (-10) dB. This antenna can be employed for ultra-wideband applications in S Band, C Band and X Band. The proposed patch antenna is designed and simulated by using IE3D 14.0 software. Simulation results are presented in terms of the resonant frequency, the return loss, VSWR, the impedance bandwidth and the impedance matching.Sat, 30 Sep 2017 20:30:00 +0100Buckling analysis of micro sandwich plate with nano coating using modified couple stress theory
http://jacm.scu.ac.ir/article_12863_0.html
Present work investigates buckling of thick sandwich plate under biaxial nonuniform compression using modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for central core the isotropic soft materials have been investigated. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations are obtained using Hamilton’s principle and considering the Von-Karman’s nonlinear strains. An analytical approach was applying to obtain exact results with different boundary conditions. Due to the fact that there are not any researches in stability of micro/nano sandwich plates based on S-FSDT including couple stress effect, so, obtained results have been compared with the FSDT papers which uses Eringen nonlocal elasticity.Tue, 16 May 2017 19:30:00 +0100Experimental Investigation on Radial Ball Bearing Parameters using Taguchi Method
http://jacm.scu.ac.ir/article_12993_0.html
In this work characteristics of various Ball Bearing parameters are studied under different loads and rotational speeds. By using Dimensional Analysis (DA) dimensionless parameters are computed which provides solution for group of parameters. This analysis can be accomplished by using Buckingham π-theorem. DA leads to reduction of the number of independent parameters involved in a problem. These independent parameters get expressed as dimensionless groups. These dimensionless groups are always ratios of important physical quantities involved in the problem of interest. In modeling and experimentation, its main function is to reduce the amount of independent variables, to simplify the solution and generalize the results. It becomes an effective method, especially if a complete mathematical model of the investigated process is not known. The present work also attempts the application of Buckingham π-theorem to find the influencing parameter π5 by using Taguchi Method.Thu, 15 Jun 2017 19:30:00 +0100Ritz method application to bending, buckling and vibration analyzes of Timoshenko beams via ...
http://jacm.scu.ac.ir/article_13028_0.html
Bending, buckling and vibration behaviors of nonlocal Timoshenko beams are investigated in this research using a variational approach. At first, governing equations of nonlocal Timoshenko beams are obtained and then weak form of these equations is outlined in this paper. Ritz technique is selected to investigate the behavior of nonlocal beams with arbitrary boundary conditions along them. To find the equilibrium equations of bending, buckling and vibration of these structures, an analytical procedure is followed. In order to verify the proposed formulation, the results for nonlocal Timoshenko beams with four classical boundary conditions are computed and compared, wherever possible. Since the Ritz technique can efficiently model the nano-sized structures with arbitrary boundary conditions, two types of beams with general boundary conditions are selected and new results are obtained.Fri, 23 Jun 2017 19:30:00 +0100Buckling and Vibration Analysis of Tapered Circular Nano-plate
http://jacm.scu.ac.ir/article_13035_0.html
In this paper, buckling and free vibration analysis of a circular tapered Nano-plate subjected to in-plane forces were studied.The linear variation of plate thickness was considered in radial direction. Nonlocal elasticity theory was employed to capture size-dependent effects. Raleigh Ritz method and differential transform method were utilized to obtain the frequency equations for simply supported and clamped boundary conditions. To verfy accuracy of Ritz method, differential transform method (DTM) also used to drive the size dependent natural frequencies of circular nano-plates. both methods reported good results.The validity of solutions was performed by comparing present results with those of the literature for both classical plate and nano plate. Effect of nonlocal parameter, mode number and taper parameter on the natural frequency were investigated. Results showed that Increasing the taper parameter causes increasing of buckling load and natural frequencies and its effects on the clamped boundary condition is more than simply support.Mon, 03 Jul 2017 19:30:00 +0100Reducing retrieval time in Automated Storage and Retrieval System with gravitational conveyor ...
http://jacm.scu.ac.ir/article_13038_0.html
The main objective of this study is to reduce the retrieval time of a list of products, by choosing, each time, the best combination of storage and retrieval rules.This is why we begin by implementing some storage rules in an Automated Storage/Retrieval System (Automated Storage and Retrieval System: AS/RS) fitted with a gravity conveyor. Some of these rules are dedicated to storage, the others to retrieval. The system is seen as a Multi-Agent System (MAS), where the produced agents are reactive agents that can interact to achieve a behavior (organizing the store). Our MAS is characterized by a decentralized control, which means that there is no preset plan. Each product merely applies a set of behavioral rules. This aims to choose the best product to be retrieved, in the shortest possible time. The product-type agents have no cognitive ability, but still perform complex tasks.Sun, 09 Jul 2017 19:30:00 +0100Quasi-static transient thermal stresses in an elliptical plate due to sectional heat supply on ...
http://jacm.scu.ac.ir/article_13045_0.html
The paper is an attempt to determine quasi-static thermal stresses, in a thin elliptical plate which is subjected to transient temperature on the top face with zero temperature on the lower face and the homogeneous boundary condition of the third kind on the fixed elliptical curved surface. The solution to conductivity equation is elucidated by employing a classical method. The solution of stress components is achieved by using Goodier’s and Airy’s potential function, involving the Mathieu and modified functions and their derivatives. The numerical results obtained are accurate enough for practical purposes for the better understanding the underlying elliptic object and for the better estimates of the thermal effect of the thermoelastic problem. Conclusions emphasise the importance of better understanding the underlying elliptic structure, improved understanding of its relationship to circular object profile, and better estimates of the thermal effect of the thermoelastic problem.Thu, 13 Jul 2017 19:30:00 +0100Vibration Analysis of Material Size Dependent CNTs Using Energy Equivalent Model
http://jacm.scu.ac.ir/article_13086_0.html
This study presents modified continuum model to investigate vibration behavior of single and multi-CNTs. Two parameters are exploited to consider size dependence, one derived from energy equivalent model and the other from modified couple stress. The energy equivalent model that derived from the basis of molecular mechanics is exploited to describe size-dependent material properties for both zigzag and armchair structures of CNTs. A modified couple stress theory is proposed to capture the microstructure size effect by assisting material length scale. A modified kinematic Timoshenko nanobeam including shear deformation and rotary inertia effects is developed. The analytical solution is shown and verified with previously published works. A parametric study is performed to study the influences of length scale parameter, translation indices of the chiral vector, and CNTs orientation on the vibration behaviors of SWCNTs. The effect of number of tube layers on the fundamental frequency of CNTs is also presented.Tue, 01 Aug 2017 19:30:00 +0100Thermal Analysis of Convective-Radiative Fin with Temperature-dependent Thermal Conductivity ...
http://jacm.scu.ac.ir/article_13087_0.html
In this paper, Chebychev spectral collocation method is applied to the thermal analysis of convective-radiative straight fin with temperature-dependent thermal conductivity. The developed heat transfer model was used to analyse the thermal performance, establish the optimum thermal design parameters and also, investigate the effects of thermo-geometric parameters and thermal conductivity (nonlinear) parameters on the thermal performance of the fin. The study reveals that the rate of heat transfer from the fin increases as convective, radiative and magnetic parameters increases. The study established good agreements between the results obtained using Chebychev spectral collocation method and the results obtained using Runge-Kutta with shooting, homotopy perturbation and Adomian decomposition methods.Thu, 03 Aug 2017 19:30:00 +0100Study of Parameters Affecting Separation Bubble Size in High Speed Flows using k-ω Turbulence Model
http://jacm.scu.ac.ir/article_13088_0.html
Shock waves generated at different parts of vehicle interact with boundary layer over the surface at high Mach flows. The adverse pressure gradient across strong shock wave causes the flow to separate. At separation and reattachment points, peak loads are generated. The size of separation bubble in shock boundary layer interaction flows depends on various parameters. Reynolds-averaged Navier-Stokes equations using standard two-equation k-ω turbulence model is used in simulations for hypersonic flows over compression corner. Different deflection angles, ranging from 15o to 38o are simulated at Mach 9.22, to study its effect on separated flow. This is followed by a variation of Reynolds number based on boundary layer thickness, Re from 1x105 to 4x105. Simulations at different constant wall conditions Tw of cool, adiabatic and hot are also performed. Lastly, the effect of free stream Mach numbers M∞ in the range of 5 to 9 on interaction region is studied. It is observed that an increase in parameters,, Re and Tw results in an increase of separation bubble length, Ls and an increase in M∞ results in a decrease of Ls.Mon, 14 Aug 2017 19:30:00 +0100Transient natural convection in an enclosure with variable thermal expansion coefficient and ...
http://jacm.scu.ac.ir/article_13099_0.html
Transient natural convection are numerically investigated in an enclosure using variable thermal conductivity, viscosity and thermal expansion coefficient of Al2O3–water nanofluid. Study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ ϕ ≤ 7%), enclosure aspect ratio (AR =1) and temperature differences between the cold and the hot walls (∆T= 30). Transient parameters such as development time and time–average Nusselt number along the cold wall are also presented as nondimentional form. Increasing Rayleigh number shorten non-dimensional time of initializing stage. By increasing the volume fraction of nanoparticles, the flow development time shows different behaviors for various Rayleigh numbers. Non-dimensional development time decreases by enhancing nanoparticles concentration.Tue, 15 Aug 2017 19:30:00 +0100Bending Response of Nanobeams Resting on Elastic Foundation
http://jacm.scu.ac.ir/article_13100_0.html
In present paper, finite element method is developed for the static analysis of nanobeams under the Winkler foundation and uniform load. Small scale effect is taken into account with Eringen's nonlocal elasticity theory. The governing equations are derived based on the principle of minimum potential energy. Galerkin weighted residual method is used to obtain the finite element equations. The validity and novelty of the results for bending are tested and comparative results are presented. Deflections according to different Winkler foundation parameters and small scale parameters are tabulated and plotted. As it can be seen clearly from figures and tables for simply-supported boundary conditions the effect of small scale parameter is very high when the Winkler foundation parameter is smaller. On the other hand, for clamped-clamped boundary condition the effect of small scale parameter is higher when the Winkler foundation parameter is high. Although the effect of small scale parameter is adverse on deflection for simply-supported and clamped-clamped boundary conditions.Mon, 21 Aug 2017 19:30:00 +0100Buckling Behaviors of Symmetric and Antisymmetric Functionally Graded Beam
http://jacm.scu.ac.ir/article_13109_0.html
The current paper investigates buckling characteristics of both nonlinear symmetric power and sigmoid functionally graded (FG) beams. The volume fractions of metal and ceramic are assumed to be distributed through a beam thickness by sigmoid-law distribution (S-FGM), and symmetric power function (SP-FGM). These functions have smooth variation of properties across boundary rather than classical power law distribution that permits gradually variation of stresses at surface boundary and eliminates delamination. Voigt model is proposed to homogenize micromechanical properties and derive the effective material properties. Euler-Bernoulli beam theory is selected to describe Kinematic relations. A finite element model is exploited to form stiffness and buckling matrices and solve the problem of eignivalue numerically. Numerical results presents the effect of material graduations, and elasticity ratios on a buckling behaviors of FG beams. The proposed model is helpful in stability of mechanical systems manufactured from FGM.Sun, 27 Aug 2017 19:30:00 +0100Finite Element Solutions of Cantilever and Fixed Actuator Beams using Augmented Lagrangian Methods
http://jacm.scu.ac.ir/article_13110_0.html
In this paper we develop a numerical procedure using finite element and augmented Lagrangian methods that simulates electro-mechanical pull-in states of both cantilever and fixed beams in microelectromechanical systems (MEMS) switches. We devise the augmented Lagrangian methods for the well-known Euler-Bernoulli beam equation which also takes into consideration of the fringing effect of electric field to allow a smooth transition of the electric field between center of a beam and edges of the beam. The numerical results obtained by the procedure are tabulated and compared with some existing results for beams in MEMS switches in literature. This procedure produces stable and accurate numerical results for simulation of these MEMS beams and can be a useful and efficient alternative for design and determining onset of pull-in for such devices.Thu, 31 Aug 2017 19:30:00 +0100Buckling analysis of embedded nanosize FG beams based on a refined hyperbolic shear deformation ...
http://jacm.scu.ac.ir/article_13152_0.html
In this paper, mechanical buckling response of refined hyperbolic shear deformable (FG) functionally graded nanobeams embedded in an elastic foundation is studied base on refined hyperbolic shear deformation theory. Material properties of FG nanobeam change continuously in thickness direction based on power-law model. To capture small size effects, Eringen’s nonlocal elasticity theory is adopted. Employing Hamilton’s principle, the nonlocal governing equations of FG nanobeams embedded in elastic foundation are obtained. To predict buckling behavior of embedded FGP nanobeams, the Navier-type analytical solution is applied to solve the governing equations. Numerical results demonstrate the influences of various parameters such as elastic foundation, power-law index, nonlocal parameter and slenderness ratio on the buckling loads of size dependent FG nanobeams.Wed, 20 Sep 2017 19:30:00 +0100Inherent irreversibility of exothermic chemical reactive third-grade poiseuille flow of a ...
http://jacm.scu.ac.ir/article_13194_0.html
In this study, the analysis of inherent irreversibility of chemical reactive third-gradepoiseuille flow of a variable viscosity with convective cooling is investigated. The dissipative heat in a reactive exothermic chemical moves over liquid in an irreversible wayand entropy is produced unceasingly in the system within the fixed walls. The heat convective exchange with the surrounding temperature at the plate surface follows Newtonslaw of cooling. The solutions of the dimensionless nonlinear equations are obtained usingweighted residual method (WRM). The solutions are used to get the Bejan number andentropy generation rate for the system. The influence of some pertinent parameters onthe entropy generation and Bejan number are illustrated graphically and discussed withrespect to the parameters.Tue, 26 Sep 2017 20:30:00 +0100MOVING MESH NON-STANDARD FINITE DIFFERENCE METHOD FOR NON-LINEAR HEAT TRANSFER IN A THIN FINITE ROD
http://jacm.scu.ac.ir/article_13202_0.html
In this paper, a moving mesh technique and a non-standard finite difference method are combined, and a moving mesh non-standard finite difference(MMNSFD) method is developed to solve an initial boundary value problem involving a quartic nonlinearity that arises in heat transfer with thermal radiation. In this method the moving spatial grid is obtained by a simple geometric adaptive algorithm for preserving stability. Also it uses variable time steps for protecting the positivity condition of solution. We compare the results of our computational technique against the corresponding uniform mesh non-standard finite difference scheme. Our simulations show that the presented method is efficient and applicable and approximates well the solutions, while corresponding uniform mesh non-standard finite difference because of producing unreal solution, fails.Sat, 30 Sep 2017 20:30:00 +0100Semi-analytical solution for vibration of nonlocal piezoelectric Kirchhoff plates resting on ...
http://jacm.scu.ac.ir/article_13203_0.html
ABSTRACT: Semi-analytical solutions for vibration analysis of nonlocal piezoelectric Kirchhoff plates resting on viscoelastic foundation with arbitrary boundary conditions are derived by developing the Galerkin strip distributed transfer function method. Based on the nonlocal elasticity theory for piezoelectric materials and Hamilton's principle, the governing equations of motion and boundary conditions are first obtained, where external electric voltage, viscoelastic foundation, piezoelectric effect and nonlocal effect are considered simultaneously. Subsequently, the Galerkin strip distributed transfer function method is developed to solve the governing equations for the semi-analytical solutions of natural frequencies. Numerical results from the model are also presented to show the effects of nonlocal parameter, external electric voltages, boundary conditions, viscoelastic foundation and geometric dimensions on vibration responses of the plate. The results demonstrate the efficiency of the proposed methods for vibration analysis of nonlocal piezoelectric Kirchhoff plates resting on viscoelastic foundation.Sat, 30 Sep 2017 20:30:00 +0100Modelling of crack growth using a new fracture criteria based peridynamics
http://jacm.scu.ac.ir/article_13213_0.html
Peridynamics (PD) is a nonlocal continuum theory based on integro-differential equations without spatial derivatives. The elongation fracture criterion is implicitly incorporated in the PD theory and fracture is a natural outcome of the simulation. On the other hand, a new fracture criterion based on the crack opening displacement combine with peridynamic (PD-COD) is proposed. When the relative deformation of the PD bond between two particles reach the critical crack tip opening displacement of the fracture mechanics, we assume that the bond force vanishes. The new damage rule of fracture criteria similar to the local damage rule in conventional PD is introduced to simulate fracture. In this paper, a comparative study between XFEM and PD is presented at first. Then , four examples, i.e. a bilateral crack problem, double parallel crack, monoclinic crack and the double inclined crack are given to demonstrate the effectiveness of the new criterion.Mon, 02 Oct 2017 20:30:00 +0100Bending of Shear Deformable Plates Resting on Winkler Foundations According to Trigonometric ...
http://jacm.scu.ac.ir/article_13234_0.html
In this paper, a trigonometric plate theory is evaluated for the bending analysis of plates resting on Winkler elastic foundation. The theory is taking into account effects of transverse shear deformation as well as transverse normal strain. The theory accounts for realistic variation of the transverse shear stress through the thickness and satisfies the traction free conditions at the top and bottom surfaces of the plate without using shear correction factors. Governing equations of equilibrium and associated boundary conditions of the theory are obtained using the principle of virtual work. A closed-form solution is obtained using double trigonometric series. The numerical results are obtained for flexure of simply supported plates subjected to various static loadings. The displacements and stresses are obtained for three different values of foundation modulus. The numerical results are also generated using higher order shear deformation theory of Reddy, first order shear deformation theory of Mindlin and classical plate theory for the comparison of present results.Wed, 18 Oct 2017 20:30:00 +0100Differential quadrature method for dynamic buckling of graphene sheet coupled by a viscoelastic ...
http://jacm.scu.ac.ir/article_13235_0.html
The dynamic buckling of graphene sheet coupled by a viscoelastic matrix has been studied in the paper. In light of the simplicity of Eringen's non-local continuum theory to considering the nanoscale influences, the theory has been employed. Equations of motion and boundary conditions were obtained using Mindlin plate theory by taking into account nonlinear strains of von Kármán and Hamilton's principle. A viscoelastic matrix was modeled as a three-parameter foundation. Furthermore, differential quadrature method was applied by which critical load has been obtained. Finally, in order to compare the results, since, there are no researches available for dynamic buckling of a nanoplate, the static buckling has been considered. The outcomes will be carried out to explain some significant and novel findings. One of these harvests shows that for greater values of nanoscale parameter, the small scale has further impacted on the dynamic buckling.Sat, 21 Oct 2017 20:30:00 +0100