scholarly journals Thermoelastic Stress and Deformation Analyses of Functionally Graded Doubly Curved Shells

2019 ◽  
Vol 3 (4) ◽  
pp. 94 ◽  
Author(s):  
Wu ◽  
He
Keyword(s):  
Material Properties ◽  
Three Dimensional ◽  
Thermoelastic Stress ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Two Phase ◽  
Finite Layer ◽  
Stress And Deformation ◽  
Finite Layer Methods ◽  
Doubly Curved

In this paper, the authors develop Reissner’s mixed variational theorem (RMVT)-based finite layer methods for the three-dimensional (3D) coupled thermoelastic analysis of simply supported, functionally graded, doubly curved (DC) shells with temperature-independent material properties. A two-phase composite material is considered to form the shell, and its material properties are assumed to obey a power–law distribution of the volume fractions of the constituents through the thickness direction of the shell. The effective material properties are estimated using the Mori–Tanaka scheme. The accuracy and convergence rate of these RMVT-based finite layer methods are validated by comparing their solutions with the quasi 3D and accurate two-dimensional solutions available in the literature.

Coupled thermo-electro-mechanical analysis of sandwiched hybrid functionally graded elastic material and piezoelectric plates under thermal loads

2017 ◽  
Vol 232 (10) ◽  
pp. 1851-1870 ◽  
Author(s):  
Chih-Ping Wu ◽  
Shuang Ding
Keyword(s):  
Elastic Material ◽  
Material Properties ◽  
Convergence Rates ◽  
Three Dimensional ◽  
Thermal Conditions ◽  
Mechanical Analysis ◽  
Functionally Graded ◽  
Thermal Loads ◽  
Finite Layer ◽  
Finite Layer Methods

Based on Reissner’s mixed variational theorem, a weak-form formulation of finite layer methods is developed for the three-dimensional coupled thermo-electro-mechanical analysis of simply-supported, functionally graded elastic material plates integrated with surface-bonded piezoelectric layers and under thermal loads. The material properties of the functionally graded elastic material core are assumed to obey the power-law distributions varying through-the-thickness coordinate of the core according to the volume fractions of the constituents, and those of the functionally graded elastic material core and piezoelectric face sheets are also temperature dependent. The effective material properties of the functionally graded elastic material are estimated using the Mori-Tanaka scheme. Two different thermal conditions, i.e. the convection conditions and specified temperature conditions, on the top and bottom surfaces of the plate are considered. The accuracies and convergence rates of the finite layer methods with various orders used for expanding the elastic and electric variables in the thickness direction are assessed by comparing their solutions with the exact three-dimensional ones available in the literature.

Modified strain gradient theory for nonlinear vibration analysis of functionally graded piezoelectric doubly curved microshells

2021 ◽  
pp. 095440622110458
Author(s):  
Vahid Movahedfar ◽  
Mohammad M Kheirikhah ◽  
Younes Mohammadi ◽  
Farzad Ebrahimi
Keyword(s):  
Nonlinear Vibration ◽  
Material Properties ◽  
Vibration Analysis ◽  
Functionally Graded ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Modified Strain Gradient Theory ◽  
Scale Parameters ◽  
Functionally Graded Piezoelectric ◽  
Doubly Curved

Based on modified strain gradient theory, nonlinear vibration analysis of a functionally graded piezoelectric doubly curved microshell in thermal environment has been performed in this research. Three scale parameters have been included in the modeling of thin doubly curved microshell in order to capture micro-size effects. Graded material properties between the top and bottom surfaces of functionally graded piezoelectric doubly curved microshell have been considered via incorporating power-law model. It is also assumed that the microshell is exposed to a temperature field of uniform type and the material properties are temperature-dependent. By analytically solving the governing equations based on the harmonic balance method, the closed form of nonlinear vibration frequency has been achieved. Obtained results indicate the relevance of calculated frequencies to three scale parameters, material gradation, electrical voltage, curvature radius, and temperature changes.

Three-dimensional natural frequency analysis of anisotropic functionally graded annular sector plates resting on elastic foundations

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Kamran Asemi ◽  
Manouchehr Salehi ◽  
Mehdi Akhlaghi
Keyword(s):  
Natural Frequency ◽  
Frequency Analysis ◽  
Material Properties ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Element Formulation ◽  
Elastic Foundations ◽  
Annular Sector ◽  
Natural Frequency Analysis

AbstractNatural frequency analysis of anisotropic functionally graded material (FGM) annular sector plates on Winkler elastic foundations based on three-dimensional theory of elasticity was investigated. The three-dimensional graded finite element formulation was derived based on the principle of minimum potential energy and the Rayleigh-Ritz method. For an orthotropic FGM, the material properties were assumed to have in-plane polar orthotropy and transverse heterogeneity according to an exponential law, whereas the mass density was assumed to be constant. For an isotropic FGM, material properties varied continuously through the thickness direction according to a power-law distribution, whereas Poisson’s ratio was set to be constant. The effects of material gradient exponents, different sector angles, different thickness ratio, Winkler parameter and two different boundary conditions on the natural frequencies and mode shapes of FGM annular sector plates have been investigated. Numerical solution was compared with the result of an FGM annular circular plate, which showed good agreement.

Hypersonic Flutter Analysis of Functionally Graded Panels under Thermal and Aerodynamic Loads

2009 ◽  
Vol 631-632 ◽  
pp. 41-46
Author(s):  
Sun Bae Kim ◽  
Ji Hwan Kim
Keyword(s):  
Material Properties ◽  
Virtual Work ◽  
Plate Theory ◽  
Equations Of Motion ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Aerodynamic Loads ◽  
Linear Rule ◽  
Structural Nonlinearity ◽  
Post Buckling

In this work, hypersonic aero-thermo post-buckling and thermal flutter behaviors of Functionally Graded (FG) panels under thermal and aerodynamic loads are investigated. The volume fractions of constitutive materials of the panels are gradually varied from ceramic to metal in the thickness direction based on a simple power law distribution. Thus, the material properties of the panel are also changed by a linear rule of mixture. Furthermore, the material properties are assumed to be temperature dependent because the panels are mainly used in the high temperature environments. Using the principle of virtual work, the equations of motion of the first-order shear deformation plate theory (FSDPT) are derived and the finite element method is applied to get the solution. In the formulation, the von Karman strain-displacement relationship is used for structural nonlinearity, and the partial second-order piston theory is adopted to consider the aerodynamic nonlinearity. Newton-Raphson iterative technique is used to solve the governing equations, and linear eigenvalue analysis is performed to obtain the hypersonic flutter boundaries.

Numerical Investigation on the Fracture Behaviors of Three-Dimensional Functionally Graded Materials

2007 ◽  
Vol 353-358 ◽  
pp. 1098-1101 ◽  
Author(s):  
Hong Jun Yu ◽  
Li Cheng Guo ◽  
Lin Zhi Wu
Keyword(s):  
Functionally Graded Materials ◽  
Crack Front ◽  
Material Properties ◽  
High Efficiency ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Parameter Analysis ◽  
Graded Materials ◽  
Gaussian Integration ◽  
Fracture Behaviors

Functionally graded materials (FGMs) with continuous varying properties have absorbed great attention for the purpose of eliminating the mismatch of material properties which may result in cracking. In this paper, three-dimensional finite element method (3D FEM) based on nonhomogeneous elements is used to study the fracture behaviors of a 3D FGM plate. Since real material properties at Gaussian integration points are adopted during forming the element stiffness matrix, the nonhomogeneous material properties can be applied in each element. Moreover, 20-node singular elements are used around the crack front to deal with the singularity of stress fields at the crack front. By this way, the stress intensity factors (SIFs) can be calculated with high efficiency and accuracy. Therefore, compared with the general FEM using homogeneouos elements, the calculating efficiency and accuracy can be increased. Finally, parameter analysis is conducted. It is found that the material nonhomogeneity constant and the crack parameter have significant influences on the SIFs.

scholarly journals Thermo-mechanical contact problems and elastic behaviour of single and double sides functionally graded brake disks with temperature-dependent material properties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mehdi Bayat ◽  
Ibrahim M. Alarifi ◽  
Ali Akbar Khalili ◽  
Tarek M. A. A. El-Bagory ◽  
Hoang Minh Nguyen ◽  
...  
Keyword(s):  
Material Properties ◽  
Radial Strain ◽  
Functionally Graded ◽  
Elastic Behaviour ◽  
Contact Friction ◽  
Vertical Force ◽  
Brake Pad ◽  
Power Law Distribution ◽  
Temperature Dependent ◽  
Brake Disk

Abstract A thermo-elastic contact problem of functionally graded materials (FGMs) rotating brake disk with different pure brake pad areas under temperature dependent material properties is solved by Finite Element Method (FEM). The properties of brake disk change gradually from metal to ceramic by power-law distribution along the radial direction from the inner to the outer surface. Areas of the pure pad are changing while the vertical force is constant. The ratio of brake pad thickness to FGMs brake disk thickness is assumed 0.66. Two sources of thermal loads are considered: (1) Heat generation between the pad and brake disk due to contact friction, and (2) External thermal load due to a constant temperature at inner and outer surfaces. Mechanical responses of FGMs disk are compared with several pad contact areas. The results for temperature-dependent and temperature-independent material properties are investigated and presented. The results show that the absolute value of the shear stress in temperature-dependent material can be greater than that for temperature-independent material. The radial stress for some specific grading index (n = 1.5) is compressive near the inner surface for double contact while it is tensile for a single contact. It is concluded that the radial strain for some specific value of grading index (n = 1) is lower than other FGMs and pure double side contact brake disks.

Numerical Studies of the Correlation between Inclusion Shape and Effective Elastic Properties of the Particle Reinforced Composites

2019 ◽  
Vol 827 ◽  
pp. 234-239
Author(s):  
Romana Piat ◽  
Pascal A. Happ
Keyword(s):  
Material Properties ◽  
Three Dimensional ◽  
Reinforced Composites ◽  
Two Phase ◽  
Smooth Structures ◽  
Irregular Shapes ◽  
Numerical Studies ◽  
Effective Material Properties ◽  
Particle Reinforced Composites ◽  
Inclusion Shape

In present paper the effect of inclusions with irregular shapes on the elastic material properties of two-phase composites is studied. The irregular shapes of the real inclusions were approximated using smooth three-dimensional structures. For this needs the images of the microscopic particles were numerically approximated through smooth structures using methods of the computer algebra and were used for the following FE studies. The reference elements with typical inclusions with irregular shapes were determined and used for calculation of the effective material properties.

scholarly journals Thermoelastic Analysis of Rotating Functionally Graded Truncated Conical Shell by the Methods of Polynomial Based Differential Quadrature and Fourier Expansion-Based Differential Quadrature

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Aref Mehditabar ◽  
Gholam H. Rahimi ◽  
Kerameat Malekzadeh Fard
Keyword(s):  
Conical Shell ◽  
Fourier Expansion ◽  
Differential Quadrature Method ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Differential Quadrature ◽  
Temperature Fields ◽  
Inertia Force ◽  
Power Law Distribution ◽  
Truncated Conical Shell

This paper focuses on the three-dimensional (3D) asymmetric problem of functionally graded (FG) truncated conical shell subjected to thermal field and inertia force due to the rotating part. The FG properties are assumed to be varied along the thickness according to power law distribution, whereas Poisson’s ratio is assumed to be constant. On the basis of 3D Green-Lagrange theory in general curvilinear coordinate, the fundamental equations are formulated and then two versions of differential quadrature method (DQM) including polynomial based differential quadrature (PDQ) and Fourier expansion-based differential quadrature (FDQ) are applied to discretize the resulting differential equations. The reliability of the present approach is validated by comparing with known literature where good agreement is reached using considerably few grid points. The effects of different mechanical boundary conditions, temperature fields, rotating angular speed, and shell thickness on the distributions of stress components and displacement in thickness direction for both axisymmetric and asymmetric cases are graphically depicted.

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