Bending and Elastic Vibration of a Novel Functionally Graded Polymer Nanocomposite Beam Reinforced by Graphene Nanoplatelets.

Yuewu Wang,Congling Shi,Tairan Fu,Ke Xie

doi:10.3390/nano9121690

Abstract

A novel functionally graded (FG) polymer-based nanocomposite reinforced by graphene nanoplatelets is proposed based on a new distribution law, which is constructed by the error function and contains a gradient index. The variation of the gradient index can result in a continuous variation of the weight fraction of graphene nanoplatelets (GPLs), which forms a sandwich structure with graded mechanical properties. The modified Halpin–Tsai micromechanics model is used to evaluate the effective Young’s modulus of the novel functionally graded graphene nanoplatelets reinforced composites (FG-GPLRCs). The bending and elastic vibration behaviors of the novel nanocomposite beams are investigated. An improved third order shear deformation theory (TSDT), which is proven to have a higher accuracy, is implemented to derive the governing equations related to the bending and vibrations. The Chebyshev–Ritz method is applied to describe various boundary conditions of the beams. The bending displacement, stress state, and vibration frequency of the proposed FG polymer-based nanocomposite beams under uniformly distributed loads are provided in detail. The numerical results show that the proposed distributions of GPL nanofillers can lead to a more effective pattern of improving the mechanical properties of GPL-reinforced composites than the common ones.

Highlights

High-strength and multifunctional polymer-based nanocomposites with low-content carbon-based nanofillers have attracted widespread attentions due to their remarkable mechanical properties such as large deformation, stretchability, good chemical compatibility, and energy storage capacity [1,2,3,4,5,6,7,8,9,10]
To better use the superior mechanical properties of carbon-based nanofillers and inspire from the concept of functionally graded material (FGM), the functionally graded carbon nanotube-reinforced composite (FG-carbon-nanotube-reinforced composite (CNTRC)) [15,16,17] and functionally graded graphene nanoplatelet reinforced composite (FG-GPLRC) [18,19,20] have been introduced, where the weight fractions of the carbon nanotubes (CNTs) and graphene nanoplatelets (GPLs) vary in the thickness direction
The second contribution of our work is to introduce a novel FG-GPLRC beam using the proposed distribution law and investigate its bending and vibration behaviors

Summary

Introduction

High-strength and multifunctional polymer-based nanocomposites with low-content carbon-based nanofillers have attracted widespread attentions due to their remarkable mechanical properties such as large deformation, stretchability, good chemical compatibility, and energy storage capacity [1,2,3,4,5,6,7,8,9,10]. To better use the superior mechanical properties of carbon-based nanofillers and inspire from the concept of FGM, the functionally graded carbon nanotube-reinforced composite (FG-CNTRC) [15,16,17] and functionally graded graphene nanoplatelet reinforced composite (FG-GPLRC) [18,19,20] have been introduced, where the weight fractions of the CNTs and GPLs vary in the thickness direction. The distribution law having adjustable parameters, which can lead to continuously graded mechanical properties for the nanofiller-reinforced polymer nanocomposites, has not been reported. It is believed that an adjustable distribution has great potential for introducing a novel type of nanocomposite, and can be used to optimize the mechanical performances of the nanofiller-reinforced structures. The first contribution of the current work is to propose a new distribution law with an adjustable parameter as the gradient index

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Results

Conclusion