Beam Theory of Thermal–Electro-Mechanical Coupling for Single-Wall Carbon Nanotubes

Abstract

The potential application field of single-walled carbon nanotubes (SWCNTs) is immense, due to their remarkable mechanical and electrical properties. However, their mechanical properties under combined physical fields have not attracted researchers’ attention. For the first time, the present paper proposes beam theory to model SWCNTs’ mechanical properties under combined temperature and electrostatic fields. Unlike the classical Bernoulli–Euler beam model, this new model has independent extensional stiffness and bending stiffness. Static bending, buckling, and nonlinear vibrations are investigated through the classical beam model and the new model. The results show that the classical beam model significantly underestimates the influence of temperature and electrostatic fields on the mechanical properties of SWCNTs because the model overestimates the bending stiffness. The results also suggest that it may be necessary to re-examine the accuracy of the classical beam model of SWCNTs.

Nonlocal Euler–Bernoulli beam theories with material nonlinearity and their application to single-walled carbon nanotubes

“…However, researchers have rarely paid attention to the material nonlinearity of nanobeams [22]. Nanobeam's nonlinearity in the thermal-electromechanical coupling also is a required eld [23][24]. Researchers have usually modi ed the classical continuum mechanics to capture the small-scale effect through three different paths: the nonlocal stress gradient model 1 − e 0 a 2 ∇ 2 σ ij = σ ij [7], the strain gradient model σ ij = 1 − e 0 a 2 ∇ 2 ε ij [9,[25][26], and the surface stress model [27].…”

Application of the Higher-Order Hamilton Approach to the Nonlinear Free Vibrations Analysis of Porous FG Nano-Beams in a Hygrothermal Environment Based on a Local/Nonlocal Stress Gradient Model of Elasticity

“…Nanostructures made of temperature-dependent functionally graded materials (FGMs) have played a key role in the advancement of nanotechnologies for the design of devices such as nanoswitches, nanosensors, nanoactuators, and nanogenerators, as well as nanoelectromechanical systems (NEMS), for use even under extreme temperature and humidity conditions [1][2][3][4][5][6][7][8]. Recent studies have also shown that, by managing some fabrication parameters during the manufacture of FGMs, different kinds of porosity distributions can be obtained within their structure to further improve the physical and mechanical characteristics of the material [9][10][11][12][13][14][15][16][17][18][19].…”

Diameter-Change-Induced Transition in Buckling Modes of Defective Zigzag Carbon Nanotubes

“…This hindrance is particularly noticeable when dealing with single-walled carbon nanotubes (SWNTs), which are expected to show nontrivial correlation between mechanical deformation and their physical properties [ 9 , 10 ]. This may be a reason why tremendous efforts based on numerical simulations [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] and continuum approximation theory [ 11 , 17 , 19 , 20 , 21 , 22 ] have been exerted in exploring the buckling behavior of SWNTs under loading. Several theoretical studies have revealed that axial buckling of SWNTs is highly dependent on the lattice irregularity [ 23 , 24 ] and tube chirality [ 25 , 26 , 27 ].…”