scholarly journals Non-stationary Response of a Carbon Nanotube-reinforced Composite Conical Shell

2020 ◽  
Vol 23 (2) ◽  
pp. 21-32
Author(s):  
Kostiantyn V. Avramov ◽  
◽  
Borys V. Uspenskyi ◽  
Nataliia H. Sakhno ◽  
Iryna V. Biblik ◽  
...  
Author(s):  
Seyed Sajad Mirjavadi ◽  
Masoud Forsat ◽  
Mohammad Reza Barati ◽  
AMS Hamouda

This research deals with the nonlinear vibration analysis of functionally graded carbon nanotubes and fiber-reinforced composite truncated conical shell segments based upon third-order shear deformation theory. A detailed procedure for obtaining material properties of the multi-scale carbon nanotube/fiber-reinforced composite based on the three-dimensional Mori–Tanaka scheme has been provided. The truncated conical shell segments have been reinforced by distributed carbon nanotubes in the thickness direction according to uniform, linear, and nonlinear functions. The nonlinear equations have been solved via both Galerkin’s technique and Jacobi elliptic function method. Based on the numerical results, the effects of diverse carbon nanotube distribution, fiber volume, fiber orientation, and semi-vertex and open angles of the segment on vibrational frequencies of the truncated conical shell have been studied.


Author(s):  
Tripuresh Deb Singha ◽  
Tanmoy Bandyopadhyay ◽  
Amit Karmakar

This article presents a numerical investigation on the free vibration characteristics of rotating pretwisted sandwich conical shell panels with two functionally graded carbon nanotube-reinforced composite (FG-CNTRC) face sheets and a homogeneous core in uniform thermal environments. The carbon nanotubes are considered to be aligned with the span length and distributed either uniformly or functionally graded along the thickness of the sandwich conical shell panel. The material properties of FG-CNTRC face sheets and homogenous core are assumed to be temperature-dependent and computed employing micromechanics models. The shallow conical shell is modeled using finite element method within a framework of the higher-order shear deformation theory. Lagrange’s equation of motion is employed to derive the dynamic equilibrium equations of sandwich conical shell panels rotating at moderate rotational speeds wherein Coriolis effect is neglected. Computer codes are developed on the basis of present mathematical formulation to determine the natural frequencies of the sandwich conical panels. Convergence and comparison studies are performed to examine the consistency and accurateness of the present formulation. The numerical results are presented to analyze the effects of various parameters on the natural frequencies of the pretwisted FG-CNTRC sandwich conical shell panels under different thermal conditions.


2018 ◽  
Vol 24 (8) ◽  
pp. 5915-5918
Author(s):  
S. Yogesh Krishnan ◽  
A. K Caitanya ◽  
P Tripathy ◽  
V. R Kar

The free vibration of carbon nanotube reinforced composite conical shell panel is examined under temperature field. In this analysis, single-walled carbon nanotube and poly(m-phenylenevinylene-co-2,5-dioctoxy-pphenylenevinylene) are used as fibre and matrix materials, respectively. The material properties are considered as temperature-dependent. The effective material properties of carbon nanotube reinforced composite panel are evaluated through the extended rule-of-mixture. The finite element model is prepared using commercially available finite element tool ANSYS APDL. An eight node Serendipity shell element (SHELL281) is used to discretize the present conical model. The displacement field is framed in the first-order shear deformation theory with six degrees of freedom. The Block Lanczos eigenvalue extraction method is used to obtain the frequency responses. In order to obtain the appropriate mesh density for the said model, the convergence study is executed for various mesh sizes. The present results are compared and validated with the previously reported results. Finally, the influences of different parameters such as length-to-thickness ratio, volume fraction and temperature on the frequency responses of the carbon nanotube reinforced composite conical shell panel are demonstrated through numerical illustrations. The results reveal that the frequency parameters of conical shell panel enhance with the volume fraction and the length-to-thickness ratio, whereas reduce with the temperature value.


2019 ◽  
Vol 17 (03) ◽  
pp. 1850133 ◽  
Author(s):  
T. Truong-Thi ◽  
T. Vo-Duy ◽  
V. Ho-Huu ◽  
T. Nguyen-Thoi

This study presents an extension of the cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements for the static and free vibration analyses of carbon nanotube reinforced composite (CNTRC) plates. The single-walled carbon nanotubes (SWCNTs) are assumed to be uniformly distributed (UD) and functionally graded (FG) distributed along the thickness direction. The material properties of carbon nanotube-reinforced composite plates are estimated according to the rule of mixture. The governing equations are developed based on the first-order shear deformation plate theory (FSDT). In the CS-DSG3, each triangular element will be divided into three sub-triangles, and in each sub-triangle, the stabilized discrete shear gap method is used to compute the strains and to avoid the transverse shear locking. Then the strain smoothing technique on the whole triangular element is used to smooth the strains on these three sub-triangles. Effects of several parameters, such as the different distribution of carbon nanotubes (CNTs), nanotube volume fraction, boundary condition and width-to-thickness ratio of plates are investigated. In addition, the effect of various orientation angles of CNTs is also examined in detail. The accuracy and reliability of the proposed method are verified by comparing its numerical solutions with those of other available results in the literature.


2017 ◽  
Vol 52 (14) ◽  
pp. 1971-1986 ◽  
Author(s):  
T Vo-Duy ◽  
T Truong-Thi ◽  
V Ho-Huu ◽  
T Nguyen-Thoi

The paper presents an efficient numerical optimization approach to deal with the optimization problem for maximizing the fundamental frequency of laminated functionally graded carbon nanotube-reinforced composite quadrilateral plates. The proposed approach is a combination of the cell-based smoothed discrete shear gap method (CS-DSG3) for analyzing the first natural frequency of the functionally graded carbon nanotube reinforced composite plates and a global optimization algorithm, namely adaptive elitist differential evolution algorithm (aeDE), for solving the optimization problem. The design variables are the carbon nanotube orientation in the layers and constrained in the range of integer numbers belonging to [−900 900]. Several numerical examples are presented to investigate optimum design of quadrilateral laminated functionally graded carbon nanotube reinforced composite plates with various parameters such as carbon nanotube distribution, carbon nanotube volume fraction, boundary condition and number of layers.


2014 ◽  
Vol 592-594 ◽  
pp. 2041-2045 ◽  
Author(s):  
B. Naresh ◽  
A. Ananda Babu ◽  
P. Edwin Sudhagar ◽  
A. Anisa Thaslim ◽  
R. Vasudevan

In this study, free vibration responses of a carbon nanotube reinforced composite beam are investigated. The governing differential equations of motion of a carbon nanotube (CNT) reinforced composite beam are presented in finite element formulation. The validity of the developed formulation is demonstrated by comparing the natural frequencies evaluated using present FEM with those of available literature. Various parametric studies are also performed to investigate the effect of aspect ratio and percentage of CNT content and boundary conditions on natural frequencies and mode shapes of a carbon nanotube reinforced composite beam. It is shown that the addition of carbon nanotube in fiber reinforced composite beam increases the stiffness of the structure and consequently increases the natural frequencies and alter the mode shapes.


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