Nonlinear Free Vibration of Functionally Graded CNT-Reinforced Composite Plates

2021 ◽  
pp. 115101
Author(s):  
J.R. Cho
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.


2021 ◽  
Vol 11 (23) ◽  
pp. 11362
Author(s):  
Zhuangzhuang Wang ◽  
Liansheng Ma

The focus of this paper is the effect of thickness stretching on the static and dynamic behaviors of functionally graded graphene reinforced composite (FG-GRC) plates. The bending and free vibration behaviors of FG-GRC plates under simply supported conditions are studied based on two plate theories, with or without taking into account the thickness stretching effect, respectively, and the effect of thickness stretching on FG-GRC plates is analyzed by comparing the calculated results of the two types of plate theories. The properties of composite materials are estimated by the modified Halpin-Tsai model and rule of mixture, Hamilton’s principle is used to construct its governing equation, and the Navier solution method is used to find the closed solution. The numerical results show that the effect of thickness stretching depends mainly on the transverse anisotropy of the FG-GRC plates, and the FG-GRC plates are most significantly affected by the thickness stretching when the graphene nanoplatelets (GPLs) are asymmetrically distributed, and the effect of thickness stretching tends to increase as the total number of layers and the weight fraction of GPLs increase.


2019 ◽  
Vol 25 (14) ◽  
pp. 2063-2078 ◽  
Author(s):  
Mahsa Heidari ◽  
Hadi Arvin

In this paper, the linear and nonlinear free vibrations of functionally graded rotating composite Timoshenko beams reinforced by carbon nanotubes are presented. The formulation is based on the assumptions of Timoshenko beam theory in addition to consideration of the nonlinear von Karman strain–displacement relationship. The effective material properties of carbon nanotube reinforced composites are determined employing the Mori–Tanaka micromechanics model and the extended mixture rule. For the carbon nanotube reinforced composite beams, uniform distribution and four types of functionally graded distribution patterns of single-walled carbon nanotube reinforcements are considered. A differential transform method is applied on the nondimensionalized equations of motion to release the flapping modeshapes and the associated natural frequencies. The direct method of multiple scales is implemented to derive the effective nonlinearity and the corresponding nonlinear natural frequency. The accuracy of the present outcomes is validated by the comparison with the results given in the literature. The numerical results are presented in both tabular and graphical forms to investigate the effects of nanotube volume fractions, distribution types of the carbon nanotubes, and rotation speed on linear and nonlinear free vibration characteristics of carbon nanotube reinforced composite beam. The results demonstrate the important role of carbon nanotube distribution profile on linear and nonlinear free vibration features.


Sign in / Sign up

Export Citation Format

Share Document