eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
200
207
10.22055/jacm.2016.12541
12541
مقاله پژوهشی
Reliability analysis of nanocomposite beams-reinforced by CNTs under buckling forces using the conjugate HL-RF
Behrooz Keshtegar
bkeshtegar@uoz.ac.ir
1
Abbasali Ghaderi
2
Ahmed El-Shafie
elshafie@um.edu.my
3
Department of Civil Engineering, University of Zabol, Zabol, 9861335-856, Iran, Bkeshtegar@uoz.ac.ir
Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan, 98798-155, Iran
Department of Civil Engineering, Faculty of Engineering, University Malaya, Kuala Lumpur, 50603, Malaysia
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.
http://jacm.scu.ac.ir/article_12541_5f3bf53debb6dad8a46bb4a8610b5453.pdf
Nanocomposite beam
Conjugate HL-RF
first order reliability method
Timoshenko beam model
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
208
221
10.22055/jacm.2016.12527
12527
مقاله پژوهشی
Nonlinear vibration analysis of single-walled carbon nanotube conveying fluid with slip boundary conditions using variational iterative method
Gbeminiyi Sobamowo
mikegbeminiyi@gmail.com
1
UNIVERSITY OF LAGOS
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.
http://jacm.scu.ac.ir/article_12527_08798b62d962ce91d27a65da02cd1919.pdf
Non-linear Vibration
Slip boundary Condition
Fluid-conveying Nanotube
Variational iteration method
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
222
229
10.22055/jacm.2016.12542
12542
مقاله پژوهشی
Magnetic field effects on the elastic behavior of polymeric piezoelectric cylinder reinforced with CNTs
Ali Cheraghbak
ali.cheraghbeyk@gmail.com
1
Abbas Loghman
aloghman@kashanu.ac.ir
2
Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
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.
http://jacm.scu.ac.ir/article_12542_16f33fd936adab43feb631d2bc65e25f.pdf
Magnetic field
CNT
Piezoelectric cylinder
Mori-Tanak model
Electric filed
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
230
242
10.22055/jacm.2016.12543
12543
مقاله پژوهشی
Uniaxial buckling analysis comparison of nanoplate and nanocomposite plate with central square cut out using domain decomposition method
Majid Jamali
eng.mjamali@gmail.com
1
Taghi Shojaee
ta_shojaee@cmps2.iust.ac.ir
2
Bijan Mohammadi
bijan_mohammadi@iust.ac.ir
3
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran, eng.mjamali@gmail.com
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran,
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran,
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.
http://jacm.scu.ac.ir/article_12543_7454edb59d6f1cfc1726fa66e0a7f9ec.pdf
Analytical buckling
Nanocomposite plate
Central square hole
Winkler foundation
Domain decomposition method
Rayleigh-Ritz energy method
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
243
253
10.22055/jacm.2016.12544
12544
مقاله پژوهشی
Optimum design of FGX-CNT-reinforced Reddy pipes conveying fluid subjected to moving load
Farid Vakili Tahami
1
Hasan Biglari
2
Morteza Raminnea
m.raminnia@tabrizu.ac.ir
3
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
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.
http://jacm.scu.ac.ir/article_12544_4b01bd90b118b192411de2968a5cb4bc.pdf
Optimization
Pipe
Moving load
Conveying fluid
DQM
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
4
254
261
10.22055/jacm.2016.12545
12545
مقاله پژوهشی
Dynamic buckling of embedded laminated nanocomposite plates based on sinusoidal shear deformation theory
Mohammd Sharif Zarei
1
Mohammad Hadi Hajmohammad
hadi.hajmohammad@gmail.com
2
Ali Nouri
3
Faculty of Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran
Department of mechanical engineering, Imam hossein University, Tehran, Iran
Department of mechanical engineering, Imam hossein University, Tehran, Iran
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 Navier’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.
http://jacm.scu.ac.ir/article_12545_46c4fcb1a204c12c376f7d8f0cc12a10.pdf
Dynamic buckling
Nanocomposite laminated plates
elastic medium
SSDT
Bolotin method