2017-10-24T13:06:27Z
http://jacm.scu.ac.ir/?_action=export&rf=summon&issue=1482
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Reliability analysis of nanocomposite beams-reinforced by CNTs under buckling forces using the conjugate HL-RF
Behrooz
Keshtegar
Abbasali
Ghaderi
Ahmed
El-Shafie
In this paper, the nonlinear conjugate map based on the conjugate Hasofer-Lind and Rackwitz- Fiessler (CHL-RF) method is applied to evaluate the reliability index using first order reliability method of the embedded noanocompsite beam, which is made from polymer reinforced with carbon nanotubs (CNTs). The structure is simulated with Timoshenko beam model. The Mori-Tanaka model is applied for calculating the effective material properties of nanocomposite beam. The surrounding elastic medium is considered by spring and shear constants. Based on energy method and Hamilton's principal, the governing equations are derived. Using an analytical method, the buckling performance function of structure is obtained. The effects of the basic random variables including the length to thickness ratio of beam (L/h), spring constant and shear constant of foundation with respect to the volume fraction of CNTs are investigated on the reliability index of the nanocomposite beam subjected to axial force of 20 GPa. The results indicated that the failure probabilities of the studied the nanocomposite beam are the sensitive to the length to thickness of beam (L/h) and spring constant of foundation variables.
Nanocomposite beam
Conjugate HL-RF
first order reliability method
Timoshenko beam model
2016
12
01
200
207
http://jacm.scu.ac.ir/article_12541_5f3bf53debb6dad8a46bb4a8610b5453.pdf
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Nonlinear vibration analysis of single-walled carbon nanotube conveying fluid with slip boundary conditions using variational iterative method
Gbeminiyi
Sobamowo
In this paper, nonlinear dynamic behaviours of carbon nanotube conveying fluidwith slip boundary conditions is studied using variation iteration method. The developed solutions are used to investigate the effects of various parameters on the nonlinear vibration of the nanotube. From the result, it is observed that increase in the slip parameter leads to decrease in the frequency of vibration and the critical velocity while natural frequency and the critical fluid velocity increase as the in stretching effect increases. As the flow velocity increases, the fundamental frequency is decreased and as flow velocity reaches the critical velocity, both the real and imaginary parts of the flexural frequency are equal to zero. Also, increasing the nonlocal parameter, the natural frequency and the critical velocity decreased. The analytical solutions can be used as starting points for better understanding of the relationship between the physical quantities of the problem.
Non-linear Vibration
Slip boundary Condition
Fluid-conveying Nanotube
Variational iteration method
2016
12
01
208
221
http://jacm.scu.ac.ir/article_12527_08798b62d962ce91d27a65da02cd1919.pdf
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Magnetic field effects on the elastic behavior of polymeric piezoelectric cylinder reinforced with CNTs
Ali
Cheraghbak
Abbas
Loghman
Magnetic field effects on the elastic response of polymeric piezoelectric cylinder reinforced with carbon nanotubes (CNTs) is studied. The cylinder is subjected to internal pressure, a constant electric potential difference at the inner and outer surfaces, thermal and magnetic fields. The Mori-Tanaka model is used for obtaining the equivalent material properties of the cylinder. Based on the charge and equilibrium relations, the governing differential equation of the cylinder is derived and solved analytically. The main purpose of this paper is to investigate the effect of magnetic field on the stresses, the electric potential and radial displacement distributions of the polymeric piezoelectric cylinder. The presented results indicate that considering magnetic field can reduce the stresses of nano-composite cylinder.
Magnetic field
CNT
Piezoelectric cylinder
Mori-Tanak model
Electric filed
2016
12
01
222
229
http://jacm.scu.ac.ir/article_12542_16f33fd936adab43feb631d2bc65e25f.pdf
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Uniaxial buckling analysis comparison of nanoplate and nanocomposite plate with central square cut out using domain decomposition method
Majid
Jamali
Taghi
Shojaee
Bijan
Mohammadi
A comparison of buckling analysis of the nanoplate and nanocomposite plate with central square hole embedded in Winkler foundation is presented in this article. In order to enhance mechanical properties of nanoplate with central cut out, carbon nano tubes (CNTs) are applied as uniform distribution (UD) through thickness direction. In order to define the shape function of plate with square cut out, domain decomposition method and orthogonal polynomials are used. At last, to obtain critical buckling load of system, Rayleigh-Ritz energy method is provided. The impacts of the length and width of plate, dimension of square cut out and elastic medium on nanoplate and nanocomposite plate are presented in this study.
Analytical buckling
Nanocomposite plate
Central square hole
Winkler foundation
Domain decomposition method
Rayleigh-Ritz energy method
2016
12
01
230
242
http://jacm.scu.ac.ir/article_12543_7454edb59d6f1cfc1726fa66e0a7f9ec.pdf
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Optimum design of FGX-CNT-reinforced Reddy pipes conveying fluid subjected to moving load
Farid
Vakili Tahami
Hasan
Biglari
Morteza
Raminnea
The harmony search algorithm is applied to optimum designs of a functionally graded (FG)-carbon naotubes (CNTs)-reinforced pipes conveying fluid subjected to moving load. The structure is modeled by Reddy cylindrical shell theory and the motion equations are derived by Hamilton's principal. Based on differential quadrature method (DQM), the dynamic displacement of system is derived. The length, thickness, diameter, velocity of load and acceleration of load, temperature of fluid, velocity of fluid, and the volume fraction of CNT are considered for design variables. The results illustrates that the optimum diameter of the pipe is decreased by increasing the CNTs volume percent. In addition, with increasing the moving load velocity and acceleration, the FS is decreased.
Optimization
Pipe
Moving load
Conveying fluid
DQM
2016
12
01
243
253
http://jacm.scu.ac.ir/article_12544_4b01bd90b118b192411de2968a5cb4bc.pdf
Journal of Applied and Computational Mechanics
JACM
2016
2
4
Dynamic buckling of embedded laminated nanocomposite plates based on sinusoidal shear deformation theory
Mohammd
Sharif Zarei
Mohammad Hadi
Hajmohammad
Ali
Nouri
In this study, dynamic buckling of embedded laminated nanocomposite plates is investigated. The plates are reinforced with single-walled carbon nanotubes (SWCNTs) where to obtain the equivalent material properties of them, Mori-Tanaka model is applied. Based on the sinusoidal shear deformation theory (SSDT), the motion equations are derived using energy method and Hamilton's principal. The Navierâ€™s method in conjunction with the Bolotin's method is used for obtaining the dynamic instability region (DIR) of the structure. The effects of different parameters such as volume percent of SWCNTs, number and orientation angle of layers, elastic medium and geometrical parameters of plates are shown on the DIR of the structure. Results indicate that increasing volume percent of SWCNTs increases the resonance frequency and shifts the DIR to right. Also, it is found that the present results have good agreement with previous researches.
Dynamic buckling
Nanocomposite laminated plates
elastic medium
SSDT
Bolotin method
2016
12
01
254
261
http://jacm.scu.ac.ir/article_12545_46c4fcb1a204c12c376f7d8f0cc12a10.pdf