Thermoelastic stability of thin CNT-reinforced composite cylindrical panels with elastically restrained edges under nonuniform in-plane temperature distribution

2021 ◽  
pp. 089270572110386
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung
Keyword(s):  
Temperature Distribution ◽  
Volume Fraction ◽  
Effective Properties ◽  
Initial Imperfection ◽  
External Pressure ◽  
Reinforced Composite ◽  
Approximate Analytical Solutions ◽  
Cylindrical Panels ◽  
Plane Temperature ◽  
Sinusoidal Temperature

In order to fill the evident lack of investigations on nonlinear response of nanocomposite curved panels under nonuniform temperature, this paper aims to analyze the nonlinear thermoelastic stability of cylindrical panels made of carbon nanotube (CNT) reinforced composite, rested on elastic foundations and subjected to sinusoidal-type in-plane temperature distribution. Reinforcement is carried out through functional rules of CNT volume fraction. An extended rule of mixture is adopted to estimate the effective properties of CNT-reinforced composite. Governing equations are derived based on classical shell theory accounting for von Kármán–Donnell nonlinearity, initial imperfection, interactive pressure from elastic foundation, and preexisting lateral pressure. In addition, the elasticity of in-plane constraints of boundary edges is included. Approximate analytical solutions are assumed to satisfy simply supported boundary conditions and Galerkin procedure is adopted to derive nonlinear closed-form relation between thermal load and deflection. Parametric studies are carried out and interesting remarks are obtained. The present study finds that, unlike case of uniform temperature rise, thermal instability of cylindrical panels under sinusoidal temperature distribution still occurs even though all edges are movable and load carrying capacity is the weakest for an intermediate value of CNT volume fraction. Under sinusoidal temperature distribution, the cylindrical panel may be deflected at the onset of loading and, for the most part, has no longer bifurcation-type buckling response. Furthermore, small values of preexisting external pressure have beneficial influences on the stability of nanocomposite cylindrical panels under nonuniform thermal loads.

scholarly journals Nonlinear buckling of CNT-reinforced composite toroidal shell segment surrounded by an elastic medium and subjected to uniform external pressure

2018 ◽  
Vol 40 (3) ◽  
pp. 285-301
Author(s):  
Hoang Van Tung ◽  
Pham Thanh Hieu
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Medium ◽  
Volume Fraction ◽  
Effective Properties ◽  
Micromechanical Model ◽  
External Pressure ◽  
Toroidal Shell ◽  
Nonlinear Load ◽  
Uniform External Pressure ◽  
Reinforced Composite

Buckling and postbuckling behaviors of Toroidal Shell Segment (TSS) reinforced by single-walled carbon nanotubes (SWCNT), surrounded by an elastic medium and subjected to uniform external pressure are investigated in this paper. Carbon nanotubes (CNTs) are reinforced into matrix phase by uniform distribution (UD) or functionally graded (FG) distribution along the thickness direction. Effective properties of carbon nanotube reinforced composite (CNTRC) are estimated by an extended rule of mixture through a micromechanical model. Governing equations for TSSs are based on the classical thin shell theory taking into account geometrical nonlinearity and surrounding elastic medium. Three-term solution of deflection and stress function are assumed to satisfy simply supported boundary condition, and Galerkin method is applied to obtain nonlinear load-deflection relation from which buckling loads and postbuckling equilibrium paths are determined. The effects of CNT volume fraction, distribution types, geometrical ratios and elastic foundation on the buckling and postbuckling behaviors of CNTRC TSSs are analyzed and discussed.

scholarly journals Nonlinear response of doubly curved sandwich panels with CNT-reinforced composite core and elastically restrained edges subjected to external pressure in thermal environments

2021 ◽  
Author(s):  
Hoang Van Tung ◽  
Dao Nhu Mai ◽  
Vu Thanh Long
Keyword(s):  
Nonlinear Response ◽  
Effective Properties ◽  
Sandwich Panels ◽  
Shear Deformation Theory ◽  
External Pressure ◽  
Functionally Graded ◽  
Thermal Environments ◽  
Reinforced Composite ◽  
Approximate Analytical Solutions ◽  
Doubly Curved

An analytical investigation on the nonlinear response of doubly curved panels constructed from homogeneous face sheets and carbon nanotube reinforced composite (CNTRC) core and subjected to external pressure in thermal environments is presented in this paper. Carbon nanotubes (CNTs) are reinforced into the core layer through uniform or functionally graded distributions. The properties of constituents are assumed to be temperature dependent and effective properties of CNTRC are determined using an extended rule of mixture. Governing equations are established within the framework of first order shear deformation theory taking into account geometrical imperfection, von Kármán–Donnell nonlinearity, panel-foundation interaction and elasticity of tangential edge restraints. These equations are solved using approximate analytical solutions and Galerkin method for simply supported panels. The results reveal that load carrying capacity of sandwich panels is stronger when boundary edges are more rigorously restrained and face sheets are thicker. Furthermore, elevated temperature has deteriorative and beneficial influences on the load bearing capability of sandwich panels with movable and restrained edges, respectively.

scholarly journals Higher-Order Thermo-Elastic Analysis of FG-CNTRC Cylindrical Vessels Surrounded by a Pasternak Foundation

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 79 ◽  
Author(s):  
Masoud Mohammadi ◽  
Mohammad Arefi ◽  
Rossana Dimitri ◽  
Francesco Tornabene
Keyword(s):  
Deformation Theory ◽  
Volume Fraction ◽  
Effective Properties ◽  
Shear Deformation Theory ◽  
Pressure Vessels ◽  
Functionally Graded ◽  
Elastic Response ◽  
Governing Equations ◽  
Third Order ◽  
Reinforced Composite

This study analyses the two-dimensional thermo-elastic response of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) cylindrical pressure vessels, by applying the third-order shear deformation theory (TSDT). The effective properties of FG-CNTRC cylindrical pressure vessels are computed for different patterns of reinforcement, according to the rule of mixture. The governing equations of the problem are derived from the principle of virtual works and are solved as a classical eigenproblem under the assumption of clamped supported boundary conditions. A large parametric investigation aims at showing the influence of some meaningful parameters on the thermo-elastic response, such as the type of pattern, the volume fraction of CNTs, and the Pasternak coefficients related to the elastic foundation.

scholarly journals Thermomechanical nonlinear stability of pressure-loaded CNT-reinforced composite doubly curved panels resting on elastic foundations

2019 ◽  
Vol 8 (1) ◽  
pp. 582-596 ◽  
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung
Keyword(s):  
Nonlinear Stability ◽  
Volume Fraction ◽  
Effective Properties ◽  
Geometrical Nonlinearity ◽  
Nonlinear Load ◽  
Elastic Foundations ◽  
Thermal Environments ◽  
Reinforced Composite ◽  
Distribution Type ◽  
Curved Panels

Abstract Nonlinear stability of nanocomposite spherical and cylindrical panels reinforced by carbon nanotubes (CNTs), resting on elastic foundations and subjected to uniform external pressure in thermal environments is investigated in this paper. CNTs are embedded into matrix phase through uniform distribution (UD) or functionally graded (FG) distribution, and effective properties of CNT-reinforced composite are estimated through an extended rule of mixture. Governing equations are based on classical shell theory taking geometrical nonlinearity, initial geometrical imperfection and panel-foundation interaction into consideration. Approximate solutions of deflection and stress functions are assumed to satisfy simply supported boundary conditions and Galerkin method is applied to obtain nonlinear load-deflection relation. Numerical examples show the effects of volume fraction and distribution type of CNTs, in-plane condition of edges, curvature of panel, thermal environments, elastic foundations and imperfection size on the nonlinear response and snap-through instability of the curved panels. The present study reveals that efficiency of CNT distribution type depends on curvature of panel and in-plane behavior of boundary edges, and bifurcation type buckling response of pressure-loaded panels may occur at elevated temperature.

scholarly journals DOUBLY PERIODIC SETS OF THIN BRANCHED INCLUSIONS IN THE ELASTIC MEDIUM: STRESS CONCENTRATION AND EFFECTIVE PROPERTIES

2013 ◽  
Vol 7 (1) ◽  
pp. 48-52
Author(s):  
Heorhiy Sulym ◽  
Iaroslav Pasternak ◽  
Serhiy Kutsyk ◽  
Wojciech Grodzki
Keyword(s):  
Stress Concentration ◽  
Elastic Medium ◽  
Volume Fraction ◽  
Effective Properties ◽  
Periodic Problem ◽  
Reinforced Composite ◽  
Coupling Principle ◽  
Periodic Sets ◽  
Element Technique ◽  
Regular Sets

Abstract This paper considers the doubly periodic problem of elasticity for anisotropic solids containing regular sets of thin branched inclusions. A coupling principle for continua of different dimension is utilized for modeling of thin inhomogeneities and the boundary element technique is adopted for numerical solution of the problem. The branches of the inclusion can interact both inside the representative volume element and at the interface of neighbor representative elements. A particular example of the elastic medium reinforced by a doubly periodic set of I-beams is considered. Stress intensity and stress concentration inside and outside thin inclusions are determined. The dependence of the effective mechanical properties of the reinforced composite material on the volume fraction of the filament and its rigidity is obtained.

Nonlinear stability of CNT-reinforced composite cylindrical panels with elastically restrained straight edges under combined thermomechanical loading conditions

2018 ◽  
Vol 33 (2) ◽  
pp. 153-179 ◽  
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung
Keyword(s):  
Nonlinear Stability ◽  
Shear Deformation Theory ◽  
Initial Imperfection ◽  
Functionally Graded ◽  
Combined Loading ◽  
Loading Conditions ◽  
Thermomechanical Loading ◽  
Elastic Foundations ◽  
Reinforced Composite ◽  
Cylindrical Panels

This article investigates the nonlinear stability of composite cylindrical panels (CPs) reinforced by carbon nanotubes (CNTs), resting on elastic foundations and subjected to combined thermomechanical loading conditions. CNTs are embedded into matrix phase through uniform distribution or functionally graded distribution. Material properties of constituents are assumed to be temperature dependent and effective elastic moduli of carbon nanotube–reinforced composite are estimated by the extended rule of mixture. Nonlinear governing equations of geometrically imperfect panels are based on first-order shear deformation theory accounting for elastic foundations and tangential constraint of straight edges. Analytical solutions are assumed to satisfy simply supported boundary conditions and closed-form expressions relating load and deflection are derived through Galerkin method. Numerical examples show the effects of preexisting nondestabilizing loads, distribution patterns, panel curvature, in-plane condition of unloaded edges, thermal environments, initial imperfection, and elastic foundations on the nonlinear stability of nanocomposite CPs under combined loading conditions.

Aeroelastic Analysis of Laminated FG-CNTRC Cylindrical Panels Under Yawed Supersonic Flow

2019 ◽  
Vol 11 (06) ◽  
pp. 1950052 ◽  
Author(s):  
Ali Ghorbanpour Arani ◽  
Farhad Kiani ◽  
Hassan Afshari
Keyword(s):  
Carbon Nanotubes ◽  
Supersonic Flow ◽  
Volume Fraction ◽  
Differential Quadrature Method ◽  
Shear Deformation Theory ◽  
External Pressure ◽  
Functionally Graded ◽  
Geometrical Parameters ◽  
Cylindrical Panels ◽  
Generalized Differential

This paper presents a parametric study on aeroelastic stability analysis of multi-layered functionally graded carbon nanotubes reinforced composite (FG-CNTRC) cylindrical panels subjected to a yawed supersonic flow. The panel is considered to be composed of different layers reinforced by carbon nanotubes arranged in different directions with various patterns and different volume fractions. Reddy’s third-order shear deformation theory (TSDT) is employed to model the structure and external pressure is estimated based on the linear supersonic piston theory. The set of governing equations and boundary conditions are derived using Hamilton’s principle and are solved numerically using generalized differential quadrature method (GDQM). Convergence and accuracy of the presented solution are confirmed and effect of volume fraction, distributions and orientation of carbon nanotubes (CNTs), yaw angle and geometrical parameters of the panel on the flutter boundaries are investigated. Results of this paper can be considered as a useful tool in design and analysis of supersonic airplanes and missiles.

scholarly journals Refinement of the Maxwell formula for a composite reinforced by circular cross-section fibres. Part II: using Padé approximants

2020 ◽  
Vol 231 (12) ◽  
pp. 5145-5157
Author(s):  
Igor I. Andrianov ◽  
Jan Awrejcewicz ◽  
Galina A. Starushenko ◽  
Vladimir A. Gabrinets
Keyword(s):  
Composite Materials ◽  
Cross Section ◽  
Volume Fraction ◽  
Effective Properties ◽  
Circular Cross Section ◽  
The Novel ◽  
High Contrast ◽  
Asymptotic Results ◽  
Reinforced Composite ◽  
Coefficient Of Thermal Conductivity

Abstract The effective properties of the fiber-reinforced composite materials with fibers of circle cross section are investigated. The novel estimation for the effective coefficient of thermal conductivity refining the classical Maxwell formula is derived. The method of asymptotic homogenization is used. For an analytical solution of the periodically repeated cell problem the Schwarz alternating process (SAP) was employed. Convergence of this method was proved by S. Mikhlin, S. Sobolev, V. Mityushev. Unfortunately, the rate of the convergence is often slow, especially for nondilute high-contrast composite materials. For improving this drawback we used Padé approximations for various forms of SAP solutions with the following additive matching of obtained expressions. As a result, the solutions in our paper are obtained in a fairly simple and convenient form. They can be used even for a volume fraction of inclusion very near the physically possible maximum value as well as for high-contrast composite constituents. The results are confirmed by comparison with known numerical and asymptotic results.

scholarly journals Buckling and postbuckling of CNT-reinforced composite sandwich cylindrical panels subjected to axial compression in thermal environments

2019 ◽  
Author(s):  
Hoang Van Tung ◽  
Vu Thanh Long
Keyword(s):  
Axial Compression ◽  
Effective Properties ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Closed Form Expression ◽  
Nonlinear Load ◽  
Thermal Environments ◽  
Reinforced Composite ◽  
Cylindrical Panels ◽  
Sandwich Model

An analytical investigation on the buckling and postbuckling behavior of carbon nanotube reinforced composite (CNTRC) sandwich cylindrical panels exposed to thermal environments and subjected to uniform axial compression is presented in this paper. Beside sandwich model with CNTRC face sheets in the literature, the present work suggests a sandwich model with CNTRC core layer and homogeneous face sheets. Carbon nanotubes (CNTs) are reinforced into matrix phase through uniform or functionally graded distributions. Effective properties of nanocomposite layers are determined according to extended rule of mixture. Formulations are based on the first order shear deformation theory taking into account Von Karman-Donnell nonlinearity. Approximate solutions are assumed to satisfy simply supported boundary conditions and Galerkin method is used to derive the closed-form expression of nonlinear load-deflection relation from which buckling loads and postbuckling paths are determined. Numerical examples are carried out and interesting remarks are given.

Design and Effective Properties of a Functionally Graded Unidirectional Fiber-Reinforced Composite

2015 ◽  
Author(s):  
Satyajit Panda
Keyword(s):  
Elastic Properties ◽  
Volume Fraction ◽  
Effective Properties ◽  
Coupled Analysis ◽  
Sigmoid Function ◽  
Thickness Direction ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Representative Volume ◽  
Reinforced Composite

The present work deals with the design of a fiber-reinforced composite lamina with varying fiber-volume fraction (FVF) along its thickness direction. In the available elastic analyses of this kind of composite, the elastic properties are evaluated based on the assumptions like continuous variation of FVF and existence of decoupled representative volume element (RVE) at every point along the thickness direction. In order to predict the graded material properties without any of these assumptions at present, first a micro-structure of similar graded composite is designed for the variation of FVF according to a sigmoid function of thickness coordinate. Next, a continuum micro-mechanics finite element model of the corresponding representative volume (RV) is derived. The RV is basically composed of several micro-volumes of different FVFs and the classical homogenization treatment is implemented over these micro-volumes without decoupling them from the overall volume of RV. The importance of this coupled analysis is verified through a parallel decoupled analysis. The effect of the total number of micro-volumes within a specified thickness of lamina on its graded elastic properties is presented. The characteristics of graded elastic properties according to the sigmoid function are also discussed.

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