Effect of Thickness Profile and FG Function on Rotating Disks Under Thermal and Mechanical Loading

2015 ◽  
Vol 32 (1) ◽  
pp. 35-46 ◽  
Author(s):  
M. Jabbari ◽  
M. Ghannad ◽  
M. Z. Nejad
Keyword(s):  
Finite Element Method ◽  
Material Properties ◽  
Functionally Graded ◽  
Rotating Disks ◽  
Graded Materials ◽  
Disk Thickness ◽  
Thermoelastic Analysis ◽  
Thickness Profile ◽  
Different Thickness ◽  
Good Agreement

AbstractIn this paper, a thermoelastic analysis of rotating disks with different thickness profiles made of functionally graded materials (FGMs) subjected to internal pressure is presented. Material properties (except Poisson’s ratio) and disk thickness profile are described by means of two functions namely power and exponential function. A comparative study of thermoelastic analysis is given for material properties and disk thickness profiles. The results of are compared with those obtained by finite element method (FEM) that shows good agreement. The effect of thickness profiles, gradient parameters and angular velocity on the thermoelastic performance of the disk have been studied.

A high-order control volume finite element method for thermoelastic analysis of functionally graded solids with mixed grids

2018 ◽  
Vol 233 (11) ◽  
pp. 3994-4013
Author(s):  
Qi Liu ◽  
Yan Yu ◽  
Pingjian Ming
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Properties ◽  
Control Volume ◽  
Functionally Graded ◽  
High Order ◽  
Shape Functions ◽  
Quadrilateral Element ◽  
Thermoelastic Analysis ◽  
Control Volume Finite Element

In this article, a new two-dimensional control volume finite element method has been developed for thermoelastic analysis in functionally graded materials. A nine-node quadrilateral element and a six-node triangular element are employed to deal with the mixed-grid problem. The unknown variables and material properties are defined at the node. The high-order shape functions of six-node triangular and nine-node quadrilateral element are employed to obtain the unknown variables and their derivatives. In addition, the material properties in functionally graded structure are also modeled by applying the high-order shape functions. The capabilities of the presented method to heat conduction problem, elastic problem, and thermoelastic problem have been validated. First, the defined location of material properties is found to be important for the accuracy of the numerical results. Second, the presented method is proven to be efficient and reliable for the elastic analysis in multi-phase materials. Third, the presented method is capable of high-order mixed grids. The memory and computational costs of the presented method are also compared with other numerical methods.

Modeling of Functionally Graded Thermopiezoelectro-Magnetic Materials

2012 ◽  
Vol 445 ◽  
pp. 487-491
Author(s):  
M. Sunar
Keyword(s):  
Finite Element Method ◽  
Magnetic Materials ◽  
Smart Materials ◽  
Material Properties ◽  
Functionally Graded ◽  
Field Analysis ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Coupled Field ◽  
Broad Subject

Previous work has shown the importance of the mechanical behaviour of coatings and thin materals, where the elastic properties vary in depth. Such coatings and materials are investigated under the broad subject of Functionally Graded Materials (FGMs). There has been also a vast interest in the general coupled field analysis of thermopiezomagnetic materials under which smart piezoelectric and magnetostrictive materials can be studied. The smart materials are often bonded as thin films on host structures for the purpose of sensing and/or actuation. This work aims to combine these two important areas of thermopiezoelectro-magnetism and FGMs. The thermopiezoelectro-magnetic materials are modeled using the finite element method assuming variations in material properties similar to FGMs. The resulting equations of modeling are then applied to an example problem in smart material sensing/actuation.

THE EFFECT OF CERAMIC IN COMBINATION OF TWO SIGMOID FUNCTIONALLY GRADED ROTATING DISKS WITH VARIABLE THICKNESS

2012 ◽  
Vol 09 (02) ◽  
pp. 1240029 ◽  
Author(s):  
M. BAYAT ◽  
B. B. SAHARI ◽  
M. SALEEM
Keyword(s):  
Variable Thickness ◽  
Functionally Graded ◽  
Rotating Disks ◽  
Thickness Profile ◽  
Metal Ceramic ◽  
Graded Material ◽  
The One ◽  
Rotating Load ◽  
Power Law Distributions ◽  
Different Thickness

This paper presents elastic solutions of a disk made of functionally graded material (FGM) with variable thickness subjected to rotating load. The material properties are represented by combination of two sigmoid FGM (S-FGM) namely aluminum–ceramic–aluminum and the disk's different thickness profiles are assumed to be represented by power law distributions. Hollow disks are considered and the solutions for the displacements and stresses are given under appropriate boundary conditions. The effects of the material grading index n and the geometry of the disk on the displacements and stresses are investigated. The results are compared with the known results in the literature on metal–ceramic–metal FGMs. Also the solutions are compared S-FGM versus FGM and non FGM and variable thickness versus uniform thickness. It is found that a sigmoid functionally graded disk with concave thickness profile has smaller displacements and stresses compared with concave or linear thickness profile. It is also observed that an S-FGM rotating functionally graded disk with metal–ceramic–metal combination can be more efficient than the one with ceramic–metal or metal–ceramic.

scholarly journals Computation of SIFs for cracked FGMs under mechanical and thermal loadings

2020 ◽  
Vol 40 (1) ◽  
pp. 12-19
Author(s):  
Yazid Ait Ferhat ◽  
Abdelkeder Boulenouar
Keyword(s):  
Material Properties ◽  
Mixed Mode ◽  
Thermal Loading ◽  
Parametric Design ◽  
Functionally Graded ◽  
Mixed Mode Fracture ◽  
Graded Materials ◽  
Ansys Parametric Design Language ◽  
Good Agreement ◽  
Displacement Extrapolation

Abstract The objective of this study is to present a numerical modeling of mixed-mode fracture in isotropic functionally graded materials (FGMs), under mechanical and thermal loading conditions. In this paper, a modified displacement extrapolation technique (DET) was proposed to calculate the stress intensity factor (SIFs) for isotropic FGMs. Using the Ansys Parametric Design Language APDL, the continuous variations of the material properties are incorporated by specified parameters at the centroid of each element. Three numerical examples are presented to evaluate the accuracy of SIFs calculated by the proposed method. Comparisons have been made between the SIFs predicted by the DET and the available reference solutions in the current literature. A good agreement is obtained between the results of the DET and the reference solutions.

Generalized displacement correlation method for mechanical and thermal fracture of FGM

2020 ◽  
Vol 09 (01) ◽  
pp. 2050004
Author(s):  
Y. Ait Ferhat ◽  
A. Boulenouar ◽  
N. Benamara ◽  
L. Benabou
Keyword(s):  
Present Method ◽  
Thermal Loading ◽  
Parametric Design ◽  
Correlation Method ◽  
Functionally Graded ◽  
Mixed Mode Fracture ◽  
Graded Materials ◽  
Displacement Based ◽  
Ansys Parametric Design Language ◽  
Good Agreement

The main objective of this work is to present a numerical modeling of mixed-mode fracture in isotropic functionally graded materials (FGMs), under mechanical and thermal loading conditions. In this paper, the displacement-based method, termed the generalized displacement correlation (GDC) method, is investigated for estimating stress intensity factor (SIF). Using the ANSYS Parametric Design Language (APDL), the continuous variations of the material properties are incorporated by specified parameters at the centroid of each element. This paper presents various numerical examples in which the accuracy of the present method is verified. Comparisons have been made between the SIFs predicted by the GDC method and the available reference solutions in the current literature. A good agreement is achieved between the results of the GDC method and the reference solutions.

scholarly journals Analysis of the Functionally Step-Variable Graded Plate Under In-Plane Compression

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4090 ◽  
Author(s):  
Leszek Czechowski ◽  
Zbigniew Kołakowski
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Functionally Graded ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Number Of Layers ◽  
Critical Equilibrium ◽  
Post Buckling ◽  
Plane Compression

A study of the pre- and post-buckling state of square plates built from functionally graded materials (FGMs) and pure ceramics is presented. In contrast to the theoretical approach, the structure under consideration contains a finite number of layers with a step-variable change in mechanical properties across the thickness. An influence of ceramics content on a wall and a number of finite layers of the step-variable FGM on the buckling and post-critical state was scrutinized. The problem was solved using the finite element method and the asymptotic nonlinear Koiter’s theory. The investigations were conducted for several boundary conditions and material distributions to assess the behavior of the plate and to compare critical forces and post-critical equilibrium paths.

Designing Optimal Volume Fractions For Functionally Graded Materials With Temperature-Dependent Material Properties

2006 ◽  
Vol 74 (5) ◽  
pp. 861-874 ◽  
Author(s):  
Florin Bobaru
Keyword(s):  
Functionally Graded Materials ◽  
Material Properties ◽  
Volume Fraction ◽  
Effective Properties ◽  
Functionally Graded ◽  
Dominant Factor ◽  
Temperature Dependent ◽  
Graded Materials ◽  
Critical Stresses ◽  
Non Linear

We present a numerical approach for material optimization of metal-ceramic functionally graded materials (FGMs) with temperature-dependent material properties. We solve the non-linear heterogeneous thermoelasticity equations in 2D under plane strain conditions and consider examples in which the material composition varies along the radial direction of a hollow cylinder under thermomechanical loading. A space of shape-preserving splines is used to search for the optimal volume fraction function which minimizes stresses or minimizes mass under stress constraints. The control points (design variables) that define the volume fraction spline function are independent of the grid used in the numerical solution of the thermoelastic problem. We introduce new temperature-dependent objective functions and constraints. The rule of mixture and the modified Mori-Tanaka with the fuzzy inference scheme are used to compute effective properties for the material mixtures. The different micromechanics models lead to optimal solutions that are similar qualitatively. To compute the temperature-dependent critical stresses for the mixture, we use, for lack of experimental data, the rule-of-mixture. When a scalar stress measure is minimized, we obtain optimal volume fraction functions that feature multiple graded regions alternating with non-graded layers, or even non-monotonic profiles. The dominant factor for the existence of such local minimizers is the non-linear dependence of the critical stresses of the ceramic component on temperature. These results show that, in certain cases, using power-law type functions to represent the material gradation in FGMs is too restrictive.

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