Buckling Behavior of Thick Porous FGM Toroidal Shell Segments Under External Pressure and Elevated Temperature Including Tangential Edge Restraint

2022 ◽  
Author(s):  
Vu Thanh Long ◽  
Hoang Tung
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Effective Properties ◽  
Shear Deformation Theory ◽  
Closed Shell ◽  
External Pressure ◽  
Functionally Graded ◽  
Toroidal Shell ◽  
Elastic Media ◽  
Buckling Resistance

Abstract Owing to mathematical and geometrical complexities, there is an evident lack of stability analyses of thick closed shell structures with porosity. The present work aims to analyze the effects of porosities, elasticity of edge constraint and surrounding elastic media on the buckling resistance capacity of thick functionally graded material (FGM) toroidal shell segments subjected to external pressure, elevated temperature and the combined action of these loads. The volume fractions of constituents are varied across the thickness according to power law functions and effective properties of the FGM are determined using a modified rule of mixture. The porosities exist in the FGM through even and uneven distributions. Governing equations are based on a higher order shear deformation theory taking into account interactive pressure from surrounding elastic media. These equations are analytically solved and closed-form expressions of buckling loads are derived adopting the two-term form of deflection along with Galerkin method. Parametric studies indicate that the porosities have beneficial and deteriorative influences on the buckling resistance capacity of thermally loaded and pressure loaded porous FGM toroidal shell segments, respectively. Furthermore, tangential constraints of edges lower the buckling resistance capacity of the shells, especially at elevated temperatures.

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.

On the Buckling of Functionally Graded Cylindrical Shells Under Combined External Pressure and Axial Compression

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
P. Khazaeinejad ◽  
M. M. Najafizadeh ◽  
J. Jenabi ◽  
M. R. Isvandzibaei
Keyword(s):  
Axial Compression ◽  
Interaction Parameter ◽  
Numerical Study ◽  
Circular Cylindrical Shell ◽  
Shear Deformation Theory ◽  
External Pressure ◽  
Functionally Graded ◽  
Buckling Loads ◽  
Graded Material ◽  
The Stability

The stability problem of a circular cylindrical shell composed of functionally graded materials with elasticity modulus varying continuously in the thickness direction under combined external pressure and axial compression loads is studied in this paper. The formulation is based on the first-order shear deformation theory. A load interaction parameter is defined to express the combination of applied axial compression and external pressure. The stability equations are derived by the adjacent equilibrium criterion method. These equations are employed to analyze the buckling behavior and obtain the critical buckling loads. A detailed numerical study is carried out to bring out the effects of the power law index of functionally graded material, load interaction parameter, thickness ratio, and aspect ratio on the critical buckling loads. The validity of the present analysis was checked by comparing the present results with those results available in literature.

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 Elastic Wave Characteristics of Graphene Reinforced Polymer Nanocomposite Curved Beams Including Thickness Stretching Effect

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2194 ◽  
Author(s):  
Pouyan Talebizadehsardari ◽  
Arameh Eyvazian ◽  
Farayi Musharavati ◽  
Roohollah Babaei Mahani ◽  
Tamer A. Sebaey
Keyword(s):  
Elastic Wave ◽  
Strain Gradient ◽  
Effective Properties ◽  
Virtual Work ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Opening Angle ◽  
Small Scale ◽  
Curved Beams ◽  
Wave Characteristics

This work aims at analyzing elastic wave characteristics in a polymeric nanocomposite curved beam reinforced by graphene nanoplatelets (GNPs). GNPs are adopted as a nanofiller inside the matrix to enhance the effective properties, which are approximated through Halpin-Tasi model and a modified rule of mixture. A higher-order shear deformation theory accounting for thickness stretching and the general strain gradient model to have both nonlocality and strain gradient size-dependency phenomena are adopted to model the nanobeam. A virtual work of Hamilton statement is utilized to get the governing motion equations and is solved in conjunction with the harmonic solution procedure. A comparative study shows the effects of small-scale coefficients, opening angle, weight fraction, the total number of layers in GNPs, and wave numbers on the propagation of waves in reinforced nanocomposite curved beams. This work is also developed for two different distribution of GNPs in a polymeric matrix, namely uniformly distribution and functionally graded one.

Nonlinear thermomechanical buckling of sandwich FGM oblique stiffened plates with nonlinear effect of elastic foundation

2020 ◽  
pp. 089270572093595
Author(s):  
Dang Thuy Dong ◽  
Vu Hoai Nam ◽  
Nguyen Thoi Trung ◽  
Nguyen Thi Phuong ◽  
Vu Tho Hung
Keyword(s):  
Elastic Foundation ◽  
Geometrical Nonlinearity ◽  
Shear Deformation Theory ◽  
Equation System ◽  
External Pressure ◽  
Functionally Graded ◽  
Geometrical Properties ◽  
Nonlinear Elastic Foundation ◽  
The Galerkin Method ◽  
Nonlinear Elastic

In this article, the nonlinear thermomechanical buckling behaviors of sandwich functionally graded plates subjected to an axial compression and external pressure are analytically analyzed resting on nonlinear elastic foundation. Assuming that the plates are reinforced by oblique stiffeners and rested on nonlinear elastic foundation. The formulations are established using the higher-order shear deformation theory taking into account the geometrical nonlinearity of von Kármán. The Lekhnitskii’s smeared stiffener technique is developed for shear deformable oblique stiffener system using the coordinate transformation technique with both mechanical and thermal terms. The Galerkin method is utilized to obtain the nonlinear algebraically equation system, then, solve it to determine the explicit expressions of critical buckling loads and postbuckling load–deflection curves. Numerical results show the effects of temperature, nonlinear elastic foundation, stiffeners, and material and geometrical properties on nonlinear behaviors of plates.

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.

Nonlinear dynamic stability of an imperfect shear deformable orthotropic functionally graded material toroidal shell segments under the longitudinal constant velocity

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6827-6850 ◽  
Author(s):  
Ahmed Y Ali ◽  
Hamad M Hasan
Keyword(s):  
Shear Deformation ◽  
Dynamic Stability ◽  
Nonlinear Dynamic ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Dynamic Buckling ◽  
Functionally Graded ◽  
Toroidal Shell ◽  
Geometrical Parameters ◽  
Nonlinear Dynamic Stability

This study investigates the nonlinear dynamic buckling of the exponentially functionally graded orthotropic toroidal shell segments under constant loading rates under the shear deformation theory with the damping influence. The properties of the shell material are assumed to be graded according to the exponential distribution function through the shell thickness direction. The shear deformation theory with von Karman nonlinearity, Stein and McElman assumption, initial imperfection, and damping effect are adopted to create the theoretical formulations. Nonlinear dynamic stability equation is solved using Galerkin's procedure and the fourth-order Runge–Kutta technique. The dynamic buckling loads are evaluated by using Budiansky–Roth criterion. Moreover, different parameter influences such as geometrical parameters, velocity, imperfections, damping ratios, and nonhomogeneous parameters on the dynamic buckling are examined in detail. The obtained results are validated with the previous publications and the good agreements are shown.

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.

scholarly journals VIBRATION OF SANDWICH BEAMS REINFORCED BY CARBON NANOTUBES UNDER A MOVING LOAD

2021 ◽  
Vol 59 (5) ◽  
Author(s):  
Thom Tran ◽  
Hien Thi Trinh ◽  
Kien Dinh Nguyen
Keyword(s):  
Carbon Nanotubes ◽  
Effective Properties ◽  
Moving Load ◽  
Shear Deformation Theory ◽  
Point Load ◽  
Functionally Graded ◽  
Element Formulation ◽  
Sandwich Beams ◽  
Third Order ◽  
Reinforced Composite

This paper studies vibration of sandwich beams reinforced by carbon nanotubes (CNTs) under a moving point load. The core of the beams is homogeneous while their two faces are of carbon nanotube reinforced composite material. The effective properties of two face sheets are determined by extended rule of mixture.  A uniform distribution (UD) and four different types of functionally graded (FG) distributions, namely FG-X, FG-FG-V, FG-O, are considered. Based on a third-order shear deformation theory, a finite element formulation is derived and used to compute the vibration characteristics of the beams. 

Sign in / Sign up

Export Citation Format

Share Document