scholarly journals EVOLUTION OF THE CARBON NANOTUBE BUNDLE STRUCTURE UNDER BIAXIAL AND SHEAR STRAINS

2020 ◽  
pp. 525
Author(s):  
Leysan Kh. Rysaeva ◽  
Dmitry V. Bachurin ◽  
Ramil T. Murzaev ◽  
Dina U. Abdullina ◽  
Elena A. Korznikova ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Shear Strain ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Shear Bands ◽  
Volumetric Strain ◽  
Structural Evolution ◽  
Biaxial Compression ◽  
Chain Model ◽  
Nanotube Bundle

Close packed carbon nanotube bundles are materials with highly deformable elements, for which unusual deformation mechanisms are expected. Structural evolution of the zigzag carbon nanotube bundle subjected to biaxial lateral compression with the subsequent shear straining is studied under plane strain conditions using the chain model with a reduced number of degrees of freedom. Biaxial compression results in bending of carbon nanotubes walls and formation of the characteristic pattern, when nanotube cross-sections are inclined in the opposite directions alternatively in the parallel close-packed rows. Subsequent shearing up to a certain shear strain leads to an appearance of shear bands and vortex-like displacements. Stress components and potential energy as the functions of shear strain for different values of the biaxial volumetric strain are analyzed in detail. A new mechanism of carbon nanotube bundle shear deformation through cooperative, vortex-like displacements of nanotube cross sections is reported.

scholarly journals ELASTIC DAMPER BASED ON THE CARBON NANOTUBE BUNDLE

2020 ◽  
Vol 18 (1) ◽  
pp. 001 ◽  
Author(s):  
Leysan Kh. Rysaeva ◽  
Elena A. Korznikova ◽  
Ramil T. Murzaev ◽  
Dina U. Abdullina ◽  
Aleksey A. Kudreyko ◽  
...  
Keyword(s):  
Phase Transition ◽  
Carbon Nanotube ◽  
Order Phase Transition ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
Mechanical Response ◽  
Compressive Strain ◽  
Period Doubling ◽  
Chain Model ◽  
Nanotube Bundle

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.

scholarly journals Mechanical Response of Carbon Nanotube Bundle to Lateral Compression

Computation ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 27 ◽  
Author(s):  
Dina U. Abdullina ◽  
Elena A. Korznikova ◽  
Volodymyr I. Dubinko ◽  
Denis V. Laptev ◽  
Alexey A. Kudreyko ◽  
...  
Keyword(s):  
Phase Transition ◽  
Carbon Nanotube ◽  
Order Phase Transition ◽  
Mechanical Response ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Structure Evolution ◽  
Biaxial Compression ◽  
Chain Model ◽  
Bending Rigidity

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.

Structural evolution of OBC/carbon nanotube bundle nanocomposites under uniaxial deformation

RSC Advances ◽  
2015 ◽  
Vol 5 (42) ◽  
pp. 32909-32919 ◽  
Author(s):  
Siduo Wu ◽  
Guangsu Huang ◽  
Jinrong Wu ◽  
Feng Tian ◽  
Hui Li
Keyword(s):  
Carbon Nanotube ◽  
Block Copolymer ◽  
Structural Evolution ◽  
Uniaxial Deformation ◽  
Long Period ◽  
Solution Blending ◽  
Nanotube Bundle ◽  
Evolution Trend ◽  
Neat Matrix

A regulated morphology of multi-walled CNT bundles in an olefin block copolymer matrix is achieved via solution blending after sonication. We observed an unexpected inverse evolution trend of long period in nanocomposites compared to that in neat matrix.

Rotobreather in a carbon nanotube bundle

2020 ◽  
Vol 05 (03) ◽  
pp. 2050010
Author(s):  
Sergey V. Dmitriev ◽  
Alexander S. Semenov ◽  
Alexander V. Savin ◽  
Marat A. Ilgamov ◽  
Dmitry V. Bachurin
Keyword(s):  
Nonlinear Dynamics ◽  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Kinetic Energy ◽  
Degrees Of Freedom ◽  
Rotational Energy ◽  
Energy Localization ◽  
Dynamics Model ◽  
Angular Velocities ◽  
Nanotube Bundle

Carbon nanotube (CNT) bundles exhibit unusual mechanical properties, but nonlinear dynamics and possible energy localization in such systems have not yet been analyzed. The dynamics of a rotobreather in the form of a CNT rotating around its axis and placed in an array of similar CNTs is analyzed using a molecular dynamics model with a reduced number of degrees of freedom. The height of the Peierls–Nabarro potential associated with the discreteness of CNTs is estimated. It is found that if a CNT is given rotational kinetic energy not sufficient to overcome the Peierls–Nabarro potential, it does not rotate. Several resonant angular velocities are identified at which the rotating CNT loses its kinetic energy relatively quickly and eventually stops rotating. CNT with a sufficiently large, non-resonant angular velocity emits the rotational energy very slowly.

scholarly journals A Dynamical Study of Fusion Hindrance with Nakajima-Zwanzig Projection Method

2021 ◽  
Author(s):  
Yasuhisa Abe ◽  
David Boilley ◽  
Quentin Hourdillé ◽  
Caiwan Shen
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Operator Method ◽  
Initial Distribution ◽  
Physical Parameters ◽  
Relaxation Processes ◽  
Fast Variable ◽  
Dynamical Study ◽  
Injection Point ◽  
Slow Variables

Abstract A new framework is proposed for the study of collisions between very heavy ions which lead to the synthesis of Super-Heavy Elements (SHE), to address the fusion hindrance phenomenon. The dynamics of the reaction is studied in terms of collective degrees of freedom undergoing relaxation processes with different time scales. The Nakajima-Zwanzig projection operator method is employed to eliminate fast variable and derive a dynamical equation for the reduced system with only slow variables. There, the time evolution operator is renormalised and an inhomogeneous term appears, which represents a propagation of the given initial distribution. The term results in a slip to the initial values of the slow variables. We expect that gives a dynamical origin of the so-called “injection point s” introduced by Swiatecki et al in order to reproduce absolute values of measured cross sections for SHE. A formula for the slip is given in terms of physical parameters of the system, which confirms the results recently obtained with a Langevin equation, and permits us to compare various incident channels.

Photocurrent in Carbon Nanotube Bundle: Graded Seebeck Coefficient Phenomenon

Nano Energy ◽  
2021 ◽  
pp. 106054
Author(s):  
Shen Xu ◽  
Hamidreza Zobeiri ◽  
Nicholas Hunter ◽  
Hengyun Zhang ◽  
Gyula Eres ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Seebeck Coefficient ◽  
Nanotube Bundle

Structural evolution in the Moine of northwest Scotland: a Caledonian linked thrust system?

1986 ◽  
Vol 123 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Robert W. H. Butler
Keyword(s):  
Cross Sections ◽  
Lower Crust ◽  
Structural Evolution ◽  
Amphibolite Facies ◽  
Metamorphic Basement ◽  
Thrust System ◽  
Lower Crustal

AbstractA model is proposed whereby the Caledonian metamorphic basement-cover complex of northwest Scotland (the Moine) is considered as a linked thrust system. This system lies between the Moine thrust at its base and the Naver–Sgurr Beag slide at its top. Ductile fold and thrust zones, which developed at mid crustal levels at metamorphic grades from greenschist to amphibolite facies, are interpreted as decoupling from a detachment presently situated at relatively shallow depths. This model is illustrated by two preliminary balanced cross-sections. These imply shortening across the northwest Scottish Caledonides in excess of 130 km and probably over 200 km. When these structures are restored onto a crustal template a considerable quantity of lower crust is found to be required at depth. The most likely location for the lower crustal wedge is beneath the Grampian Highlands.

Nonlinear Six-Degree-of-Freedom Dynamic Model for Risers, Pipelines, and Beams

1986 ◽  
Vol 30 (03) ◽  
pp. 177-185
Author(s):  
Michael M. Bernitsas ◽  
John E. Kokarakis
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Nonlinear Effects ◽  
Nonlinear Formulation ◽  
Marine Risers ◽  
Internal Fluid ◽  
Rotational Degrees Of Freedom ◽  
Six Degree Of Freedom ◽  
Structural Imperfections ◽  
Inertia Forces

A nonlinear model for the dynamic behavior of tubular beams such as marine risers, pipelines, legs of tension leg platforms, and drill strings is developed. The formulation includes three translational degrees of freedom of the riser cross section and three rotational degrees of freedom for shear and torsion. Nonlinear constitutive equations for cross sections of unequal principal stiffnesses and extensible material are derived. Initial structural imperfections which are inherent in long risers are modeled in the form of initial curvature and geometric torsion which do not induce strains. The inertia forces due to the motion of the riser and internal fluid motions are formulated. The external hydrodynamic and hydrostatic forces are integrated on the riser surface as pressure and traction forces. The model is a comprehensive consistent nonlinear formulation of the riser dynamics and can be used for evaluation of the significance of nonlinear effects.

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