Critical buckling load of honeycomb sandwich panels reinforced by three-phase orthotropic skins enhanced by carbon nanotubes

2020 ◽  
Vol 237 ◽  
pp. 111904 ◽  
Author(s):  
Michele Bacciocchi ◽  
Angelo Marcello Tarantino
Keyword(s):  
Carbon Nanotubes ◽  
Sandwich Panels ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Three Phase ◽  
Honeycomb Sandwich

Critical Buckling Load of Triple-Walled Carbon Nanotube Based on Nonlocal Elasticity Theory

2020 ◽  
Vol 62 ◽  
pp. 108-119
Author(s):  
Tayeb Bensattalah ◽  
Ahmed Hamidi ◽  
Khaled Bouakkaz ◽  
Mohamed Zidour ◽  
Tahar Hassaine Daouadji
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Axial Compression ◽  
Buckling Load ◽  
Small Scale ◽  
Beam Model ◽  
Buckling Loads ◽  
Critical Buckling Load ◽  
Nonlocal Continuum Theory ◽  
Walled Carbon Nanotubes

The present paper investigates the nonlocal buckling of Zigzag Triple-walled carbon nanotubes (TWCNTs) under axial compression with both chirality and small scale effects. Based on the nonlocal continuum theory and the Timoshenko beam model, the governing equations are derived and the critical buckling loads under axial compression are obtained. The TWCNTs are considered as three nanotube shells coupled through the van der Waals interaction between them. The results show that the critical buckling load can be overestimated by the local beam model if the small-scale effect is overlooked for long nanotubes. In addition, a significant dependence of the critical buckling loads on the chirality of zigzag carbon nanotube is confirmed, and these are then compared with: A single-walled carbon nanotubes (SWCNTs); and Double-walled carbon nanotubes (DWCNTs). These findings are important in mechanical design considerations and reinforcement of devices that use carbon nanotubes.

scholarly journals Buckling Analysis of Composite Cylindrical Shells Reinforced by Carbon Nanotubes

2012 ◽  
Vol 59 (4) ◽  
pp. 413-434 ◽  
Author(s):  
Jafar Eskandari Jam ◽  
Esmail Asadi
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Volume Fraction ◽  
Cylindrical Shells ◽  
Ritz Method ◽  
Orientation Angle ◽  
Effective Elastic Modulus ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Compressive Axial Load

In this paper, the authors investigate a cylindrical shell reinforced by carbon nanotubes. The critical buckling load is calculated using analytical method when it is subjected to compressive axial load. The Mori-Tanaka method is firstly utilized to estimate the effective elastic modulus of composites having aligned oriented straight CNTs. The eigenvalues of the problem are obtained by means of an analytical approach based on the optimized Rayleigh-Ritz method. There is presented a study on the effects of CNTs volume fraction, thickness and aspect ratio of the shell, CNTs orientation angle, and the type of supports on the buckling load of cylindrical shells. Furthermore the effect of CNTs agglomeration is investigated when CNTs are dispersed none uniformly in the polymer matrix. It is shown that when the CNTs are arranged in 90_ direction, the highest critical buckling load appears. Also, the results are plotted for different longitudinal and circumferential mode numbers. There is a specific value for aspect ratio of the cylinder that minimizes the buckling load. The results reveal that for very low CNTs volume fractions, the volume fraction of inclusions has no important effect on the critical buckling load.

On the Finite Element Modelling and Simulation of Carbon Nanotubes

2014 ◽  
Vol 607 ◽  
pp. 55-61 ◽  
Author(s):  
Ghasem Ghadyani ◽  
Mojtaba Akbarzade ◽  
Andreas Öchsner
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Beam Theory ◽  
Elastic Stiffness ◽  
Buckling Load ◽  
Timoshenko Beams ◽  
Bernoulli Beam ◽  
Critical Buckling Load ◽  
Beam Elements ◽  
Mesh Density

In this paper, two different beam elements (i.e. according to the Bernoulli beam and Timoshenko beam theory) for the modeling of the behavior of carbon nanotubes are applied. Finite element models are developed for this study with variation of chirality for both zig-zag and armchair configurations of CNTs. The deformations from the finite element simulations are subsequently used to predict the elastic stiffness and the critical buckling load in terms of material and geometric parameters. Furthermore, the dependence of mechanical properties on the kind of beam element and the mesh density is also compared. Based on the obtained results, Youngs modulus and critical buckling load of structures using Timoshenko beams are clearly lower than the Bernoulli beam approach for all chiralities.

Buckling characteristics of embedded multi-walled carbon nanotubes

2005 ◽  
Vol 461 (2064) ◽  
pp. 3785-3805 ◽  
Author(s):  
K.M Liew ◽  
X.Q He ◽  
S Kitipornchai
Keyword(s):  
Carbon Nanotubes ◽  
Approximate Expression ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Number Of Layers ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Walled Cnts ◽  
Vdw Interaction

An analytical algorithm is proposed to describe the buckling behaviour of multi-walled carbon nanotubes (CNTs) that are embedded in a matrix with consideration of the van der Waals (vdW) interaction. The individual tube is treated as a cylindrical shell, but the tube deflections are coupled with each other due to the vdW interaction. The interaction between the matrix and the outermost tube is modelled as a Pasternak foundation. Based on the proposed model, an accurate expression and a simple approximate expression are derived for the buckling load of double-walled CNTs that are embedded in a matrix. The approximate expression clearly indicates that the vdW force is coupled with the matrix parameters. A numerical simulation is carried out, and the results reveal that the increase in the number of layers leads to a decrease in the critical buckling load for multi-walled CNTs with a fixed innermost radius. In contrast, when the outermost radius is fixed, the critical buckling load increases with the increase in the number of layers for multi-walled CNTs without a matrix. However, for multi-walled CNTs that are embedded in a matrix, the critical buckling load decreases first and then increases with the increase in the number of layers. This implies that there is a given number of layers for a multi-walled CNT at which the critical buckling load is the lowest, and that this number depends on the matrix parameters.

Designing pinhole vacancies in graphene towards functionalization: Effects on critical buckling load

2017 ◽  
Vol 103 ◽  
pp. 343-357 ◽  
Author(s):  
S.K. Georgantzinos ◽  
S. Markolefas ◽  
G.I. Giannopoulos ◽  
D.E. Katsareas ◽  
N.K. Anifantis
Keyword(s):  
Buckling Load ◽  
Critical Buckling Load
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