scholarly journals Thermomechanical Buckling Analysis of the E&P-FGM Beams Integrated by Nanocomposite Supports Immersed in a Hygrothermal Environment

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6594
Author(s):  
Mohammad Khorasani ◽  
Luca Lampani ◽  
Rossana Dimitri ◽  
Francesco Tornabene
Keyword(s):  
Middle Layer ◽  
Functionally Graded ◽  
Displacement Fields ◽  
Virtual Displacement ◽  
Buckling Behavior ◽  
Graded Material ◽  
Carbon Nano Tubes ◽  
Hygrothermal Environment ◽  
Displacement Approach ◽  
The Impact

Due to the widespread use of sandwich structures in many industries and the importance of understanding their mechanical behavior, this paper studies the thermomechanical buckling behavior of sandwich beams with a functionally graded material (FGM) middle layer and two composite external layers. Both composite skins are made of Poly(methyl methacrylate) (PMMA) reinforced by carbon-nano-tubes (CNTs). The properties of the FGM core are predicted through an exponential-law and power-law theory (E&P), whereas an Eshelby–Mori–Tanaka (EMT) formulation is applied to capture the mechanical properties of the external layers. Moreover, different high-order displacement fields are combined with a virtual displacement approach to derive the governing equations of the problem, here solved analytically based on a Navier-type approximation. A parametric study is performed to check for the impact of different core materials and CNT concentrations inside the PMMA on the overall response of beams resting on a Pasternak substrate and subjected to a hygrothermal loading. This means that the sensitivity analysis accounts for different displacement fields, hygrothermal environments, and FGM theories, as a novel aspect of the present work. Our results could be replicated in a computational sense, and could be useful for design purposes in aerospace industries to increase the tolerance of target productions, such as aircraft bodies.

Low-Velocity Impact on a Functionally Graded Circular Thin Plate

2006 ◽  
Author(s):  
Pantele Chelu ◽  
Liviu Librescu
Keyword(s):  
Plate Theory ◽  
Equation System ◽  
Functionally Graded ◽  
Low Velocity Impact ◽  
Thin Plates ◽  
Low Velocity ◽  
Alternative Analysis ◽  
Velocity Impact ◽  
Graded Material ◽  
The Impact

In this paper, an alternative analysis strategy based on a Wavelet-Galerkin scheme specially tailored to solve impact problems of functionally graded orthotropic thin plates subjected to low-velocity impact is presented. The plate considered to be circular, is assumed to be clamped on its lateral edge and has internal supports of rigid, elastic and viscoelastic types. The material properties of the plate are represented in the form of exponential functions of the thickness coordinate. A rigid spherical indenter impacts the plate. The study is based on the classical lamination plate theory (CLT). An advanced contact law of the Hertzian type is adopted. A nonlinear Volterra integral equation system is obtained in the following unknown functions: the impact force and the dynamic reaction forces at the rigid, elastic and viscoelastic internal point supports. Numerical simulations displaying the contact force, the transversal displacement and the penetration depth are graphically presented, and pertinent conclusions regarding the implications of incorporation of graded material systems are outlined.

scholarly journals An application of isogeometric analysis for active control the solid functionally graded material plates with actuator patches using piezoelectric material

2020 ◽  
Vol 2 (SI2) ◽  
pp. First
Author(s):  
Khuong Duy Nguyen ◽  
Nguyen Manh Tien ◽  
Nguyen Xuan Hung ◽  
Vu Cong Hoa
Keyword(s):  
Piezoelectric Material ◽  
Active Control ◽  
Functionally Graded Material ◽  
Isogeometric Analysis ◽  
Piezoelectric Materials ◽  
Middle Layer ◽  
Basic Function ◽  
Functionally Graded ◽  
Three Dimensional Model ◽  
Graded Material

This paper applies isogeometric analysis (IGA) to simulate active control of the functionally graded material (FGM) plates by using piezoelectric material patches. This control helps to reduce the deflection of the plate under the effect of static load, which makes the structure more resistant to loading. IGA is built on the non-uniform rational basis spline (NURBS) basic function with many advantages such as: describing geometry exactly by approximating by higher order function and directly using this function to approach procedure. Furthermore, NURBS geometry has mesh flexibility and high continuity between elements, making the problem highly accurate. Three-dimensional model for plate-like structure consists of upper and lower layers made of piezoelectric materials, the middle layer is FGM. The obtained results will be verified with the published results to prove the efficiency of the proposed method for this problem. Through the obtained results, it is shown that IGA is used effectively for the active control problem by piezoelectric patches to reduce the displacement of FGM plates. The efficiency shown when using a small number of degrees of freedom but still ensuring the solution has accurate results when compared with the reference solution.

BUCKLING ANALYSIS OF FUNCTIONALLY GRADED SKEW PLATES: AN EFFICIENT FINITE ELEMENT APPROACH

2013 ◽  
Vol 05 (04) ◽  
pp. 1350041 ◽  
Author(s):  
M.N.A. GULSHAN TAJ ◽  
ANUPAM CHAKRABARTI
Keyword(s):  
Finite Element ◽  
Volume Fraction ◽  
Shear Deformation Theory ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Element Formulation ◽  
Skew Angle ◽  
Buckling Behavior ◽  
Metal Plates ◽  
Graded Material

In the present study, an attempt has been made to present the Co finite element formulation based on third order shear deformation theory for buckling analysis of functionally graded material skew plate under thermo-mechanical environment. Here, prime emphasis has been given to study the influence of skew angle on the buckling behavior of functionally graded plate. Two dissimilar homogenization schemes, namely Mori–Tanaka scheme and Voigt rule of mixture are employed to sketch their influence for the interpretation of data. Temperature-dependent material properties of the constituents of the plate are considered to perform thermal analysis. Numerical examples are solved using different mixture of ceramic and metal plates to generate the new results and relative imperative conclusions are highlighted. The roles played by the different factors like loading condition, volume fraction index, skew angle, boundary condition, aspect ratio, thickness ratio and homogenization schemes on buckling behavior of the FGM skew plates are presented in the form of tables and figures.

Three-dimensional analysis of a functionally graded coating/substrate system of finite thickness

2008 ◽  
Vol 366 (1871) ◽  
pp. 1821-1826 ◽  
Author(s):  
M Kashtalyan ◽  
M Menshykova
Keyword(s):  
Finite Thickness ◽  
Three Dimensional ◽  
Thermomechanical Properties ◽  
Functionally Graded ◽  
Displacement Fields ◽  
Functionally Graded Coating ◽  
Graded Coating ◽  
Graded Material ◽  
Coating Type ◽  
Coating Design

The concept of functionally graded material (FGM) is currently actively explored in coating design for the purpose of eliminating the mismatch of thermomechanical properties at the interfaces and thus increasing the resistance of coatings to functional failure. In the present paper, three-dimensional elastic deformation of a functionally graded coating/substrate system of finite thickness subjected to mechanical loading is investigated. A comparative study of FGM versus homogeneous coating is conducted to examine the effect of the coating type on stress and displacement fields in the system.

scholarly journals Vibrations of Three-Layered Cylindrical Shells with FGM Middle Layer Resting on Winkler and Pasternak Foundations

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Abdul Ghafar Shah ◽  
Aalia Ali ◽  
Muhmmad Nawaz Naeem ◽  
Shahid Hussain Arshad
Keyword(s):  
Cylindrical Shell ◽  
Wave Propagation ◽  
Functionally Graded Material ◽  
Middle Layer ◽  
Functionally Graded ◽  
Numerical Results ◽  
Thickness Direction ◽  
Dynamical Equations ◽  
Elastic Foundations ◽  
Graded Material

Vibrations of a cylindrical shell composed of three layers of different materials resting on elastic foundations are studied out. This configuration is formed by three layers of material in thickness direction where the inner and outer layers are of isotropic materials and the middle is of functionally graded material. Love shell dynamical equations are considered to describe the vibration problem. The expressions for moduli of the Winkler and Pasternak foundations are combined with the shell dynamical equations. The wave propagation approach is used to solve the present shell problem. A number of comparisons of numerical results are performed to check the validity and accuracy of the present approach.

scholarly journals Hygrothermal environment effect on the critical buckling load of FGP microbeams with initial curvature integrated by CNT-reinforced skins considering the influence of thickness stretching

2021 ◽  
Vol 10 (1) ◽  
pp. 1140-1156
Author(s):  
Mohammad Alkhedher
Keyword(s):  
Couple Stress Theory ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Buckling Load ◽  
Polar Coordinates ◽  
Curved Beams ◽  
Virtual Displacement ◽  
Initial Curvature ◽  
The Core ◽  
Hygrothermal Environment

Abstract Due to the need for structures with refined properties to bear against different loading conditions, recently, carbon nanotubes (CNTs) have been used widely to reinforce them. The extremely high stiffness of CNTs makes them significant as one of the best reinforcements to improve the mechanical behaviors of structures. This work focuses on microbeam buckling response with an initial curvature that includes three layers. The mid-layer that is known as the core is constituted of functionally graded porous (FGP) materials and two CNT-reinforced composite skins are bonded to the core to integrate it. The whole structure is affected by the hygrothermal environment and springs and shear layers are put below it. For the first time, for such a structure, a refined shear deformation theory (RSDT) as a higher-order theory that considers thickness stretching effect in polar coordinates is used that presents more accurate results, especially for deeply curved beams. Modified couple stress theory (MCST) in combination with the virtual displacement principle is utilized to establish the governing equations. The obtained results demonstrate the significance of porosity percentage and CNTs’ addition to the skins on the critical nanotubes buckling load. Also, the different behaviors of the microstructure at various temperatures are analyzed and discussed in detail.

scholarly journals Nonlinear Buckling of Fixed Functionally Graded Material Arches Under a Locally Uniformly Distributed Radial Load

2021 ◽  
Vol 8 ◽  
Author(s):  
Hanwen Lu ◽  
Jinman Zhou ◽  
Zhicheng Yang ◽  
Airong Liu ◽  
Jian Zhu
Keyword(s):  
Limit Point ◽  
Functionally Graded ◽  
Buckling Load ◽  
Equilibrium Path ◽  
Radial Load ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Bifurcation Buckling ◽  
Nonlinear Equilibrium ◽  
Graded Material

Functionally graded material (FGM) arches may be subjected to a locally radial load and have different material distributions leading to different nonlinear in-plane buckling behavior. Little studies is presented about effects of the type of material distributions on the nonlinear in-plane buckling of FGM arches under a locally radial load in the literature insofar. This paper focuses on investigating the nonlinear in-plane buckling behavior of fixed FGM arches under a locally uniformly distributed radial load and incorporating effects of the type of material distributions. New theoretical solutions for the limit point buckling load and bifurcation buckling loads and nonlinear equilibrium path of the fixed FGM arches under a locally uniformly distributed radial load that are subjected to three different types of material distributions are derived. The comparisons between theoretical and ANSYS results indicate that the theoretical solutions are accurate. In addition, the critical modified geometric slendernesses of FGM arches related to the switches of buckling modes are also derived. It is found that the type of material distributions of the fixed FGM arches affects the limit point buckling loads and bifurcation buckling loads as well as the nonlinear equilibrium path significantly. It is also found that the limit point buckling load and bifurcation buckling load increase with an increase of the modified geometric slenderness, the localized parameter and the proportional coefficient of homogeneous ceramic layer as well as a decrease of the power-law index p of material distributions of the FGM arches.

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