Nanocomposite Plates Research Articles

Free vibrations and buckling analysis of cross-ply composite nanoplates by means of a Mesh Free Radial Point Interpolation Method

The paper deals with the dynamic analysis of composite simply supported nanoplates modelled according to the second order strain gradient theory. Numerical results are obtained by means of a Mesh Free Radial Point Interpolation Method. Both uniaxial and biaxial buckling as well as free vibration analysis are considered. The buckling analysis is performed on plates with different aspect ratio a/b and variable E1/E2 ratio. For the vibration analysis, the geometry and mechanical properties of the plate are kept constant while different lamination sequences are accounted for. Moreover, different values of the nonlocal parameter ℓ are considered for both analyses. Finally, the numerical results are compared against the analytical results find in the literature, the comparison being made in terms of percentage error between the two.

Application of the piezoelectricity as the effective solution to energy management of the composite structures exposed to abrupt thermal load

This study pays special attention to practical solutions for declining the harmful impacts of thermal shock loading applied on the nanocomposite rectangular plate. The governing equations are obtained in the content of three-dimensional elasticity theory to establish an appropriate approach to achieving reliable results. Due to the time-dependent nature of the applied shock, it is essential to analyze the system’s transient response. Accordingly, the Laplace transform is used to set out the state-space form of the governing equations from time to the Laplace domain. The reliability of the results is verified by comparing them with those recorded in the literature.

Interaction of angular velocity and temperature rise in the thermo-inertia bifurcation buckling of FG laminated nanocomposite annular plates

The present study examines the asymmetric stability of a functionally graded (FG) nanocomposite shear deformable annular plate with a constant angular speed in the thermal environment. For the first time, this phenomenon is investigated for a structure augmented with graphene platelets (GPLs). The displacement field in the annular system is estimated depending on the first-order shear deformation plate assumptions called FSDT. Moreover, the von-Kármán premise of geometrically nonlinear relations is utilized to achieve the equilibrium equations and related edge constraints. To recognize the stability relations in a linearized style, the adjacent equilibrium criterion is utilized. Applying a combined solution procedure consisting of the trigonometric expansion along the hoop axis and the generalized differential quadrature along the radius axis (TE-GDQ), the achieved stability equations are solved, and novel numerical results are obtained. An eigenvalue problem is solved to calculate the critical temperature rise for thermal buckling and the required angular velocity for rotating buckling. Based on the various GPL parameters, geometric properties, and boundary conditions, novel numerical findings are developed to illustrate the interplay of thermal and rotational buckling.

Effect of moisture on the nonlinear viscoelastic fracture behavior of polymer nanocompsites: a finite deformation phase-field model

The mechanisms underlying damage in high-performance polymer nanocomposites are remarkably affected by hygrothermal conditions. In this study, we develop a phase-field formulation to investigate the influence of hygrothermal conditions on the nonlinear viscoelastic fracture behavior of epoxy resins and their nanocomposites at finite deformation. For this, the Helmholtz free energy, capturing the effect of temperature and moisture and nanoparticle contents, is defined based on an additive decomposition of the energy into an equilibrium, a non-equilibrium, and a volumetric contribution with different definitions under tensile and compressive loading. The coupled displacement phase-field problem is solved using a quasi-Newton monolithic algorithm and a staggered solution scheme. Numerical examples show that the monolithic algorithm is more efficient. Simulations are performed to investigate the effect of temperature, deformation rate, and moisture content on the force–displacement response of boehmite nanoparticle/epoxy samples in benchmark numerical problems. Comparing numerical predictions and experimental data for compact-tension tests shows good agreement at different nanoparticle contents. Also, the model’s capability to predict fracture patterns is evaluated using simulations of single-edge notched nanocomposite plates under tensile and shear loading.

Static and free vibration analyses of functionally graded porous skew plates reinforced by graphene platelet based on three-dimensional elasticity theory

This paper deals with the static and free vibration analyses of FG porous skew plates reinforced by graphene platelets (GPL). The plate comprises of a layered model with uniform or non-uniform dispersion of graphene platelets in a metallic matrix including open-cell interior pores. The extended rule of mixture in conjunction with the modified Halpin–Tsai approach is used to obtain the equivalent properties of the porous nanocomposite plate. Three various types of porosity distributions are assumed through the plate thickness including uniform and two kinds of symmetric functionally graded distributions. Besides, five various kinds of GPL dispersion patterns are assumed along the plate thickness. By substituting in the expression for functional of element and Rayleigh–Ritz method, the equations of motion are derived and a 3D FEM approach is applied to solve the governing equation of motions. The influences of different parameters including various porosity coefficients, porosity distribution in conjunction with GPL pattern and the weight fraction of GPL as nanofiller, different boundary conditions and various angles of skew plates on static response, and free vibration behavior of the skew nanocomposite plate have been surveyed.

Nonlinear static analysis of CNT/nanoclay particles reinforced polymer matrix composite plate using secant function based shear deformation theory

ABSTRACT The mechanically induced nonlinear statical assessment of the bending response of single-walled carbon nanotubes (CNTs) fibers on nanoclay-particle-reinforced polymer hybrid laminated composite plate is explored under static loading conditions. A numerical approach is used to find the mechanical properties of CNT-reinforced hybrid laminated plates prepared by involving nanoclay particles in the existing CNT-reinforced epoxy composites. The transverse nonlinear central deflection of a hybrid nanocomposite subjected to mechanical loading based on the Halpin–Tsai approach is evaluated. For the fundamental formulation, a secant-function-based shear deformation theory (SFSDT) and von Kármán nonlinearity are implemented. The influence of CNT/nanoclay particles over the nonlinear bending responses of the hybrid laminated plate under various loading circumstances is studied in detail. A Newton–Raphson method based on nonlinear finite element technique is used for the hybrid nanocomposite plate. Furthermore, the impact of different design parameters, such as thicknesses of CNT fibers, different interphases along with aspect ratios, stacking sequences under different boundary conditions, and the types of loads on the nonlinear transverse central deflection of CNT/nanoclay-reinforced polymer hybrid composite plate, has been investigated. The effectiveness of the suggested model has been confirmed by comparing it to deflection reactions found in the literature.

Simultaneous effect of CaCO3 nanoparticles and waste ground rubber tire powder on forced vibration of polypropylene nanocomposite plates: An experimental investigation

In this study, the effect of the simultaneous incorporation of different contents of CaCO3 nanoparticles (NPs) and waste ground rubber tire powder (WGRT) on the forced vibration behavior of polypropylene (PP) was experimentally investigated. Hammer test with modal analysis was performed to investigate the vibrational behavior of the composite plates with one edge clamped (CFFF) support condition. Microstructural assessment of composites using Field Emission Scanning Electron Microscope (FESEM) images showed that a rise in CaCO3 nanoparticles in small weight percentages led to better dispersion and a decline in the tire phase size in the small weight percentage of WGRT. Moreover, a comparison of the modal analysis results revealed that all ternary composites, except in the first mode, had a higher damped natural frequency than pure PP. The damping ratio of all ternary composites, especially in the first and second modes, was higher than pure PP, which is due to the combined effect of WGRT and CaCO3 nanoparticles in increasing energy dissipation and damping of composites.

Analysis of Electromagnetic Effects on Vibration of Functionally Graded GPLs Reinforced Piezoelectromagnetic Plates on an Elastic Substrate

A new nanocomposite piezoelectromagnetic plate model is developed for studying free vibration based on a refined shear deformation theory (RDPT). The present model is composed of piezoelectromagnetic material reinforced with functionally graded graphene platelets (FG-GPLs). The nanocomposite panel rests on Winkler–Pasternak foundation and is subjected to external electric and magnetic potentials. It is assumed that the electric and magnetic properties of the GPLs are proportional to those of the electromagnetic materials. The effective material properties of the plate are estimated based on the modified Halpin–Tsai model. A refined graded rule is introduced to govern the variation in the volume fraction of graphene through the thickness of the plate. The basic partial differential equations are provided based on Hamilton’s principle and then solved analytically to obtain the eigenfrequency for different boundary conditions. To check the accuracy of the present formulations, the depicted results are compared with the published ones. Moreover, impacts of the variation in elastic foundation stiffness, plate geometry, electric potential, magnetic potential, boundary conditions and GPLs weight fraction on the vibration of the smart plate are detailed and discussed.

Resonator vibration of a magneto-electro-elastic nano-plate integrated with FGM layer subjected to the nano mass-Spring-damper system and a moving load

The present study investigates the free and forced vibration of the composite nanoplate with an attached nano mass-spring-damper system. The mentioned composite constitutes three layers in which the core layer is assumed to be a functionally graded material, and the top and the bottom surfaces are supposed to be magneto-electro-elastic material. Eringen’s nonlocal theory is used to consider the small-scale effect, and the mentioned system is assumed to rest of the Winkler and Pasternak medium. Governing equations are determined based on the first-order shear deformation theory and extended Hamilton’s principle. Two coupled ordinary differential equation and partial differential equation of the nanoplate's governing equations are solved analytically with the aid of Laplace and Navier-type transforms. The impact of various parameters such as nonlocal parameter, gradient index, the magnitude of the attached mass, load velocity is considered and explained in detail. The present research results indicate that increasing the magneto-electro-elastic layer thickness increases the natural frequency. To peruse the present study's precision and efficacy, the proposed system results are compared with the articles accessible in the literature. The results of the existing investigation can be used in drug delivery, biosensors, and designing resonators.

Nonlinear Static Stability of Stiffened Nanocomposite Plate s Subjected Various Types of Loads

This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated.
 Keywords: Stiffened FG CNTRC plates; Buckling and Post buckling analysis; Third-order shear deformation theory; Thermal environment; Galerkin method
 This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated.

Nonlinear static and dynamic performance of CNT reinforced and nanoclay modified laminated nanocomposite plate

Under static and dynamic loading circumstances, the mechanically and thermo-initiated nonlinear static and dynamic assessment of the bending response of single-walled carbon nanotubes’ (CNTs’) fibers with a nanoclay particle reinforced polymer hybrid laminated composite plate is investigated. To evaluate the effective elastic characteristics of the CNTs’ fibers on the nanoclay particle modified polymer hybrid laminated plate, a modified Halpin–Tsai method is applied in an orthotropic way. The theory of higher-order shear deformation and complete kinematics (nonlinear) are used to develop the fundamental nonlinear dynamic formulation. A user-interactive finite element method-based MATLAB program solves the governing equations for nonlinear dynamic systems utilizing Newmark’s period integration and the Newton–Raphson method. The effects of variation in the quantity of CNTs’ fibers and particles of nanoclay, presence of interphases around CNTs’ fibers and nanoclay particles, variation in phases of the CNTs’ fibers on the nanoclay particle modified polymer hybrid laminated plate, and variation in plies of the laminated hybrid plate under clamped and simply supported conditions on the transverse central deflection response are explored in depth.

Flexoelectricity and surface effects on coupled electromechanical responses of graphene reinforced functionally graded nanocomposites: A unified size-dependent semi-analytical framework

Owing to inhomogeneous strain and high surface-to-volume ratio in nanostructures, it is imperative to account for the flexoelectricity as well as surface effect while analyzing the size-dependent electromechanical responses of nano-scale piezoelectric materials. In this article, a semi-analytical ‘single-term extended Kantorovich method (EKM)’ and ‘Ritz method’ based powerful framework is developed for investigating the static and dynamic electromechanical responses of graphene reinforced piezoelectric functionally graded (FG) nanocomposite plates, respectively. The residual surface stresses, elastic and piezoelectric surface modulus, and direct flexoelectric effects are taken into account while developing the unified governing equations and boundary conditions. The modified Halpin Tsai model and rules of mixture are implemented to predict the effective bulk properties. Our results reveal that the static deflection and resonance frequency of the proposed FG nanoplates are significantly influenced due to the consideration of flexoelectricity and surface effects. While such outcomes emphasize the fact that such effects cannot be ignored, these also open up the notion of on-demand property modulation and active control. The effects are more apparent for nanoplates of lesser thickness, but they diminish as plate thickness increases, leading to the realization and quantification of a size-dependent behavior. Based on the developed unified formulation, a comprehensive numerical investigation is further carried out to characterize the electromechanical responses of nanoplates considering different critical parameters such as plate thicknesses, aspect ratios, flexoelectric coefficients, piezoelectric multiples, distribution, and weight fraction of graphene platelets along with different boundary conditions. With the recent advances in nano-scale manufacturing, the current work will provide the necessary physical insights in modeling size-dependent multifunctional systems for active control of mechanical properties and harvesting electromechanical energy.

Buckling response of laminated FG-CNT reinforced composite plates: Analytical and finite element approach

A 3D finite element model using suitable user subroutines in ABAQUS finite element software and an analytical solution based on the third-order shear deformation laminated plate theory combined with von Kármán's geometric nonlinearity are proposed to simulate the functionally graded Carbon Nanotubes (CNTs) throughout a plate's thickness. The former is used for the estimation of the buckling response and the latter is used for the estimation of both buckling and post-buckling response of laminated nanocomposite plates under uniform and parabolic loading. In the analytical approach, the governing equations are solved by the Galerkin method and Airy's stress function to obtain the buckling coefficient of FG-CNT reinforced composite plates. The effect of various factors, such as boundary conditions, types of loads, distribution type and volume fraction of CNTs, geometrical parameters, etc on the buckling and post-buckling response is investigated. It has been found that a higher volume fraction of CNTs increases the buckling and post-buckling strength of laminated composite plates, whereas the laminated plate with angle-ply orientations equal to 45 degrees has the maximum buckling load factor among the CNT fiber orientations considered.

A closed-form solution for thermoelastic stress analysis of perforated asymmetric functionally graded nanocomposite plates

Issues related to stress concentration in cracks, perforated plates, and the use of new generation materials to strengthen this type of plates are of great importance. When a functionally graded carbon nanotube-reinforced composite plate (FG-CNTRC) has a hole in its center of the plate that is exposed to a combination of mechanical and thermal loads, due to various couplings such as bending-extension, shear-extension, and bend-twist couplings that occur in the stress–strain relationships and due to the presence of nonhomogeneous equations, the analytical solution approach will be accompanied by new challenges. Hence, a general solution for the FG-CNTRC plates weakened by a central hole is presented. To achieve this goal, the Lekhnitskii complex potential approach is developed using the appropriate conformal mapping function. The present solution provides the ability to calculate the stress distribution of perforated plates made of asymmetric composite laminates and functionally graded materials by introducing holomorphic potential functions in the form of Laurent series. In this research, an attempt has been made to depict the effect of important parameters on the stress resultants and moments around the hole. The results clearly show that the studied parameters significantly change the stress resultants and moments due to thermal and mechanical loads applied to perforated FG-CNTRC plates. As a result, it is possible to significantly reduce stress resultants and moments by properly selecting the values of effective parameters in the design of such perforated plates.

XFEM crack growth virtual monitoring in self-sensing CNT reinforced polymer nanocomposite plates using ANSYS

This paper presents an eXtended Finite Element Method (XFEM)-based numerical scheme to compute electrical resistivity changes caused by the presence of cracks and the crack growth. Using the commercial finite element package ANSYS, the virtual continuous monitoring of the structure is solved in two steps. First, the strain response of the cracked composite domain is computed by means of the XFEM. In the second step, the electrical conductivity of the piezorresistive elements located in the domain are updated according to the strain state and the electric resistance between two electrodes of the damaged plate is computed. The comparison with the electric resistance measured for the undamaged plate allows us to detect the presence of a crack and its severity. Moreover, the crack growth process can be also monitored via the electric resistance increments. Several numerical studies are provided to show the capabilities of this computational framework.

Poro-thermo-elasticity analysis of the functionally graded nanocomposite sandwich plate reinforced with CNTs

Poro-thermo-elasticity analysis of the functionally graded nanocomposite sandwich plate reinforced with CNTs

Fe-CoP/C composite nanoplate derived from 2D porphyrin MOF as an efficient catalyst for oxygen evolution reaction

The 2D Fe-CoP/C composite transformed from 2D PPF-5-Fe/Co MOF presents a high activity for the oxygen evolution reaction in alkaline media.

Evaluation of the effect of MWCNT amount and dispersion on bending fatigue properties of non-crimp CFRP composites

Multi-walled carbon nanotubes (MWCNTs) have many unique features that improve composite material properties, including a large surface area, thermal and chemical stability, and thermal and electrical conductivity. Our study aimed to examine the influence of MWCNT weight percentage on the fatigue characteristics of a polymer matrix composite strengthened with carbon fiber in fabric form. This study aimed to explore the additional properties and functions of these MWCNTs. For the experiments, MWCNTs were prepared by mixing them in solution with epoxy in three different weight percentages (0.5 %, 1.0%, and 1.5%) using a surfactant, and at 0.5 wt% without a surfactant. The prepared solutions were injected into four-axis non-crimp carbon fiber fabric plates via the vacuity mixture method and then cured for 48 h to produce nanocomposite plates. Using five types of composites, fatigue tests were carried out at six different amplitudes and a fixed frequency. Fatigue test specimens were subjected to detailed SEM analysis of their fatigue fracture surfaces. The investigational results revealed that the 0.5 wt% MWCNT epoxy solution had been homogeneously dispersed and exhibited the highest absorbance spectrum. The 0.5 wt% MWCNT specimen achieved the highest value in the fatigue life experiments. In addition, electron microscopy studies of the fracture surfaces of the test specimens determined that individual COOH-MWCNTs interrelated with the fibers and formed a bridge between fiber and matrix, whereas agglomerations caused weak bonding between the reinforcement fibers and matrix, making the material more brittle.

Nonlinear impulsive and vibration analysis of nonlocal FG-CNT reinforced sandwich plate by considering agglomerations

This paper is focused on impulsive and subsequent vibration response of a nano-scale composite sandwich plate considering both nonlocal effect and nanoparticle agglomerations. In particular, the core is homogeneous polymethyl methacrylate (PMMA) and the face sheet is PMMA matrix with functionally graded carbon nanotubes (short for FG-CNT). The material properties are given by Eshelby-Mori-Tanaka's approach taking into account of CNT agglomerations. The equations of motion for the FG-CNT reinforced nanoplate are derived based on nonlocal strain gradient theory, Reddy's higher order shear deformation theory and von-Karman nonlinear deformation theory. The impulsive and vibration problems for simply supported FG-CNT plates are solved using Galerkin method and Newton iteration method where the solutions have been verified with the literature. By considering impulsion of step load, exponential load and sinusoidal load and, it is found that weaker size effect, fewer CNT agglomerations, higher CNT content, smaller functional gradient, thinner core, bigger aspect ratio and larger length thickness ratio can enhance the stiffness of the nanoplate and thus will induce smaller center displacement during the load process and higher free vibration frequency after unloading, regardless of load type. However, the subsequent vibration amplitude is significantly influenced by the impulsive load type. Among the material parameters, minimizing size effect and agglomerations could greatly improve the structural stiffness whereas the improvement by varying functional gradient is very limited. It is the first time that a FG-CNT reinforced sandwich plate, especially considering nonlocal effect and nanoparticle agglomerations, is treated in the context of impulsive and subsequent vibration problems. The solutions presented in this paper could provide a benchmark for the design and manufacture of such a composite nanoplate.

A computational three-dimensional elasticity theory for bending and frequency analysis of the axisymmetric circular/annular plates via machine learning and discrete singular convolution integration methods

The present study deals with the frequency and bending behavior of annular/circular nanocomposite plates. The nanocomposite is made of three-phase materials of graphene oxide (nanoscale) and carbon fibers (microscale), and epoxy matrix (macro-scale) in multiple layers of different orientations. The governing equation extracted to investigate the multiscale hybrid laminated nanocomposite reinforced (MHLNR) is a three-dimensional elasticity theory. Furthermore, the whole structure is on the elastic substrate, which takes into account the horizontal forces in the calculations. The displacement compatibility and equilibrium condition are considered in the interlayers of the three, five, and seven layers of the composite structure. The bulk material properties at each layer are evaluated utilizing fiber micromechanics and Halpin–Tsai equations. The discrete singular convolution method is employed to transform the equations and solve equations. The obtained results are further verified using several references in this field. In addition, an adaptively tuned deep neural network model is designed based on the data of the current study to predict the results. Finally, a comprehensive parametric study is carried out to demonstrate the influences of different parameters on the internal stress field and frequency responses of the current sandwich structure.