Reliability analysis of nanocomposite beams-reinforced by CNTs under buckling forces using the conjugate HL-RF
Behrooz
Keshtegar
Department of Civil Engineering, University of Zabol,
Zabol, 9861335-856, Iran, Bkeshtegar@uoz.ac.ir
author
Abbasali
Ghaderi
Department of Civil Engineering, University of Sistan and Baluchestan,
Zahedan, 98798-155, Iran
author
Ahmed
El-Shafie
Department of Civil Engineering, Faculty of Engineering, University Malaya,
Kuala Lumpur, 50603, Malaysia
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
200
207
http://jacm.scu.ac.ir/article_12541_5f3bf53debb6dad8a46bb4a8610b5453.pdf
dx.doi.org/10.22055/jacm.2016.12541
Nonlinear vibration analysis of single-walled carbon nanotube conveying fluid with slip boundary conditions using variational iterative method
Gbeminiyi
Sobamowo
UNIVERSITY OF LAGOS
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
208
221
http://jacm.scu.ac.ir/article_12527_08798b62d962ce91d27a65da02cd1919.pdf
dx.doi.org/10.22055/jacm.2016.12527
Magnetic field effects on the elastic behavior of polymeric piezoelectric cylinder reinforced with CNTs
Ali
Cheraghbak
Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
author
Abbas
Loghman
Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
222
229
http://jacm.scu.ac.ir/article_12542_16f33fd936adab43feb631d2bc65e25f.pdf
dx.doi.org/10.22055/jacm.2016.12542
Uniaxial buckling analysis comparison of nanoplate and nanocomposite plate with central square cut out using domain decomposition method
Majid
Jamali
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran, eng.mjamali@gmail.com
author
Taghi
Shojaee
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran,
author
Bijan
Mohammadi
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran,
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
230
242
http://jacm.scu.ac.ir/article_12543_7454edb59d6f1cfc1726fa66e0a7f9ec.pdf
dx.doi.org/10.22055/jacm.2016.12543
Optimum design of FGX-CNT-reinforced Reddy pipes conveying fluid subjected to moving load
Farid
Vakili Tahami
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
author
Hasan
Biglari
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
author
Morteza
Raminnea
Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
243
253
http://jacm.scu.ac.ir/article_12544_4b01bd90b118b192411de2968a5cb4bc.pdf
dx.doi.org/10.22055/jacm.2016.12544
Dynamic buckling of embedded laminated nanocomposite plates based on sinusoidal shear deformation theory
Mohammd
Sharif Zarei
Faculty of Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran
author
Mohammad Hadi
Hajmohammad
Department of mechanical engineering, Imam hossein University, Tehran, Iran
author
Ali
Nouri
Department of mechanical engineering, Imam hossein University, Tehran, Iran
author
text
article
2016
eng
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.
Journal of Applied and Computational Mechanics
Shahid Chamran University of Ahvaz
2383-4536
2
v.
4
no.
2016
254
261
http://jacm.scu.ac.ir/article_12545_46c4fcb1a204c12c376f7d8f0cc12a10.pdf
dx.doi.org/10.22055/jacm.2016.12545