The Mechanical Response of Aligned Carbon Nanotube Mats via Transmitted Laser Intensity Measurements

2008 ◽  
Author(s):  
Christian Deck ◽  
Chinung Ni ◽  
Kenneth Vecchio ◽  
Prabhakar Bandaru
2020 ◽  
Vol 7 (1) ◽  
pp. 153-165
Author(s):  
Rajendran Selvamani ◽  
M. Mahaveer Sree Jayan ◽  
Rossana Dimitri ◽  
Francesco Tornabene ◽  
Farzad Ebrahimi

AbstractThe present paper aims at studying the nonlinear ultrasonic waves in a magneto-thermo-elastic armchair single-walled (SW) carbon nanotube (CNT) with mass sensors resting on a polymer substrate. The analytical formulation accounts for small scale effects based on the Eringen’s nonlocal elasticity theory. The mathematical model and its differential equations are solved theoretically in terms of dimensionless frequencies while assuming a nonlinear Winkler-Pasternak-type foundation. The solution is obtained by means of ultrasonic wave dispersion relations. A parametric work is carried out to check for the effect of the nonlocal scaling parameter, together with the magneto-mechanical loadings, the foundation parameters, the attached mass, boundary conditions and geometries, on the dimensionless frequency of nanotubes. The sensitivity of the mechanical response of nanotubes investigated herein, could be of great interest for design purposes in nano-engineering systems and devices.


Computation ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 27 ◽  
Author(s):  
Dina U. Abdullina ◽  
Elena A. Korznikova ◽  
Volodymyr I. Dubinko ◽  
Denis V. Laptev ◽  
Alexey A. Kudreyko ◽  
...  

Structure evolution and mechanical response of the carbon nanotube (CNT) bundle under lateral biaxial compression is investigated in plane strain conditions using the chain model. In this model, tensile and bending rigidity of CTN walls, and the van der Waals interactions between them are taken into account. Initially the bundle in cross section is a triangular lattice of circular zigzag CNTs. Under increasing strain control compression, several structure transformations are observed. Firstly, the second-order phase transition leads to the crystalline structure with doubled translational cell. Then the first-order phase transition takes place with the appearance of collapsed CNTs. Further compression results in increase of the fraction of collapsed CNTs at nearly constant compressive stress and eventually all CNTs collapse. It is found that the potential energy of the CNT bundle during deformation changes mainly due to bending of CNT walls, while the contribution from the walls tension-compression and from the van der Waals energies is considerably smaller.


Author(s):  
Kane M. Barker ◽  
Al Ferri ◽  
Lawrence A. Bottomley

Carbon nanotubes are useful in a variety of measurement applications. In the case of Atomic Force Microscopes (AFMs), carbon nanotubes can be affixed to the tip of the AFM cantilever to improve image resolution and enable images of surfaces with deep crevices and trench structures. In this paper, the mechanical response of long, straight, small walled carbon nanotubes (SWNTs) under compressive and tensile load is examined with an atomic force microscope. Multi-dimensional force spectroscopy (MDFS) is used to simultaneously measure the cantilever resonant frequency, deflection, and scanner motion. The acquired force curves reveal that the SWNT buckles shortly after contact is initiated. As the scanner continues to rise and then reverses direction, the SWNT undergoes a number of adhesion/sticking episodes, buckling, and slip events. The bulk properties of the nanotube are estimated by measuring the shift in natural frequency during tension. Finally, the carbon nanotube is modeled as an elastica in order to predict the post-buckled shape of the SWNT. By comparing the model results with MDFS results, the static coefficient of friction between the SWNT and a variety of surfaces is estimated. The study suggests that MDFS has a wide applicability for studying the mechanical and adhesive properties of various nanotubes, nanorods and nanofibers.


2020 ◽  
Vol 18 (1) ◽  
pp. 001 ◽  
Author(s):  
Leysan Kh. Rysaeva ◽  
Elena A. Korznikova ◽  
Ramil T. Murzaev ◽  
Dina U. Abdullina ◽  
Aleksey A. Kudreyko ◽  
...  

Mechanical response of the carbon nanotube bundle to uniaxial and biaxial lateral compression followed by unloading is modeled under plane strain conditions. The chain model with a reduced number of degrees of freedom is employed with high efficiency. During loading, two critical values of strain are detected. Firstly, period doubling is observed as a result of the second order phase transition, and at higher compressive strain, the first order phase transition takes place when carbon nanotubes start to collapse. The loading-unloading stress-strain curves exhibit a hysteresis loop and, upon unloading, the structure returns to its initial form with no residual strain. This behavior of the nanotube bundle can be employed for the design of an elastic damper.


2019 ◽  
Vol 86 (12) ◽  
Author(s):  
Igor Ostanin ◽  
Traian Dumitrică ◽  
Sebastian Eibl ◽  
Ulrich Rüde

Abstract In this work, we present a computational study of the small strain mechanics of freestanding ultrathin carbon nanotube (CNT) films under in-plane loading. The numerical modeling of the mechanics of representatively large specimens with realistic micro- and nanostructure is presented. Our simulations utilize the scalable implementation of the mesoscopic distinct element method of the waLBerla multi-physics framework. Within our modeling approach, CNTs are represented as chains of interacting rigid segments. Neighboring segments in the chain are connected with elastic bonds, resolving tension, bending, shear, and torsional deformations. These bonds represent a covalent bonding within the CNT surface and utilize enhanced vector model (EVM) formalism. Segments of the neighboring CNTs interact with realistic coarse-grained anisotropic van der Waals potential, enabling a relative slip of CNTs in contact. The advanced simulation technique allowed us to gain useful insights on the behavior of CNT materials. It was established that the energy dissipation during CNT sliding leads to extended load transfer that conditions size-independent, material-like mechanical response of the weakly bonded assemblies of CNTs.


2016 ◽  
Vol 8 (41) ◽  
pp. 28004-28011 ◽  
Author(s):  
Benjamin F. Davis ◽  
Xingyi Yan ◽  
Nitin Muralidharan ◽  
Landon Oakes ◽  
Cary L. Pint ◽  
...  

1976 ◽  
Vol 80 (20) ◽  
pp. 2248-2253 ◽  
Author(s):  
J. N. Demas ◽  
R. P. McBride ◽  
E. W. Harris

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