Nonlocal beam theory for nonlinear vibrations of embedded multiwalled carbon nanotubes in thermal environment

2011 ◽  
Vol 67 (3) ◽  
pp. 2241-2254 ◽  
Author(s):  
R. Ansari ◽  
H. Ramezannezhad ◽  
R. Gholami
2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Ismail Kucuk ◽  
Ibrahim S. Sadek ◽  
Sarp Adali

Variational principles are derived for multiwalled carbon nanotubes undergoing linear vibrations using the semi-inverse method with the governing equations based on nonlocal Timoshenko beam theory which takes small scale effects and shear deformation into account. Physical models based on the nonlocal theory approximate the nanoscale phenomenon more accurately than the local theories by taking small scale phenomenon into account. Variational formulation is used to derive the natural and geometric boundary conditions which give a set of coupled boundary conditions in the case of free boundaries which become uncoupled in the case of the local theory. Hamilton's principle applicable to this case is also given.


2005 ◽  
Vol 128 (3) ◽  
pp. 419-427 ◽  
Author(s):  
Xiaohu Yao ◽  
Qiang Han

The buckling of multiwalled carbon nanotubes under torsional load coupling with temperature change is researched. The effects of torsional load, temperature change, surrounding elastic medium, and van der Waals forces between the inner and outer nanotubes are taken into account at the same time. Using continuum mechanics, an elastic multishell model with thermal effect is presented for buckling of a multiwalled carbon nanotube embedded in an elastic matrix under thermal environment and torsional load. Based on the model, numerical results for the general case are obtained for the thermal effect on buckling of a multiwalled carbon nanotube under torsional load. It is shown that the buckling torque of a multiwalled carbon nanotube under a certain value of temperature change is dependent on the wave number of torsional buckling modes, and a conclusion is drawn that at room or lower temperature the critical torsional load for infinitesimal buckling of a multiwalled carbon nanotube increases as the value of temperature change increases, while at temperature higher than room temperature the critical torsional load for infinitesimal buckling of a multiwalled carbon nanotube decreases as the value of temperature change increases.


2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  

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