scholarly journals Mechanical Behavior of Porous Functionally Graded Nanocomposite Materials

2019 ◽  
Vol 5 (2) ◽  
pp. 34 ◽  
Author(s):  
A. F. Mota ◽  
M. A. R. Loja
Keyword(s):  
Finite Element Method ◽  
Biomedical Applications ◽  
Nanocomposite Materials ◽  
Functionally Graded ◽  
Structural Performance ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Bending Tests ◽  
Materials Used ◽  
American Society

Materials used in biomedical applications need to cope with a wide set of requisites, one of them being their structural adequacy to a specific application. Thus, it is important to understand their behavior under specified standard cases, namely concerning their structural performance. This objective constituted the focus of the present study, where nanocomposite functionally graded materials integrating different porosity distributions were analyzed. To this purpose a set of numerical simulations based on the finite element method, reproducing American Society for Testing and Materials (ASTM) tensile and bending tests were considered. The results obtained show a good performance of the models implemented through their preliminary verification. It is also possible to conclude that carbon nanotubes and porosity distributions provide different and opposite effects in the context of the nanocomposite materials analyzed.

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.

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.

Production of a Helicopter Tail Boom and Associated Mechanical Tests

2012 ◽  
Vol 445 ◽  
pp. 566-570
Author(s):  
Deniz Kavrar ◽  
M. Lutfy Öveçoğlu ◽  
Halit S. Türkmen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Structure ◽  
Mechanical Tests ◽  
The Other ◽  
Structural Performance ◽  
Pitching Moment ◽  
Main Rotor ◽  
The Finite Element Method ◽  
Materials Used

The lightweight materials such as composites are often used for the aerospace structures. One of the uses of these materials is for the tail boom of helicopters. Tail booms are the structures connecting the tail rotor to the fuselage. It is mainly subjected to the pitching moment and torsion. Because it is long to obtain the enough distance between the tail rotor and the main rotor, the materials used for manufacturing the tail boom needs to be a lightweight material. The structural optimization of the tail boom is also necessary. In this study, two different tail booms are manufactured by using laminated composites. The tail booms considered in this study are a semi-monocoque structure consisted of skins and stiffeners. These skins and stiffeners are made of carbon/epoxy. One is produced by using 3-ply carbon/epoxy and it is strengthened using stiffeners. The other is produced by using honeycomb between 2-layers of carbon/epoxy. A hand lay-up technique is used for the manufacturing of the tail booms. The vacuum bagging and a moderate heat are used to cure the composite structure. The bending and bending with torsion tests are performed to determine the structural performance of the tail booms. The tail boom is also modeled using the finite element method and analyses are performed. The results are presented and discussed.

Parametric Formulation of the Finite-Volume Theory for Functionally Graded Materials—Part II: Numerical Results

2006 ◽  
Vol 74 (5) ◽  
pp. 946-957 ◽  
Author(s):  
Marcio A. A. Cavalcante ◽  
Severino P. C. Marques ◽  
Marek-Jerzy Pindera
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Volume ◽  
Functionally Graded Materials ◽  
Exact Analytical Solution ◽  
Functionally Graded ◽  
Structural Components ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Element Method

In Part I of this communication, the finite-volume theory for functionally graded materials was further extended to enable efficient analysis of structural components with curved boundaries, as well as efficient modeling of continuous inclusions with arbitrarily-shaped cross sections of a graded material’s microstructure, previously approximated using discretizations by rectangular subcells. This was accomplished through a parametric formulation based on mapping of a reference square subcell onto a quadrilateral subcell resident in the actual microstructure. In Part II, the parametric formulation is verified through comparison with analytical solutions for homogeneous and graded curved structural components subjected to transient thermal and steady-state thermomechanical loading. Grading is modeled using piecewise uniform thermoelastic moduli assigned to each discretized region. Results for a heterogeneous microstructure in the form of a single inclusion embedded in the matrix phase of large dimensions are also generated and compared with the exact analytical solution, as well as with the results obtained using the standard version of the finite-volume theory based on rectangular discretization and the finite-element method. It is demonstrated that the parametric finite-volume theory is a very competitive alternative to the finite-element method based on the quality of results and execution time.

Elastic analysis of exponential FGM disks subjected to internal and external pressure

2013 ◽  
Vol 3 (3) ◽  
Author(s):  
Mohammad Nejad ◽  
Majid Abedi ◽  
Mohammad Lotfian ◽  
Mehdi Ghannad
Keyword(s):  
Radial Direction ◽  
Circumferential Stress ◽  
External Pressure ◽  
Functionally Graded ◽  
Elastic Analysis ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Material Inhomogeneity ◽  
Closed Form Analytical Solution ◽  
Stress Profiles

AbstractAssuming exponential varying properties in the radial direction and constant Poisson’s ratio, a closed-form analytical solution based on the elasticity theory is obtained to elastic analysis of disks made of functionally graded materials (FGMs) subjected to internal and external pressure. Following this, radial displacement, radial stress, and circumferential stress profiles are plotted for different values of material inhomogeneity constant, as a function of radial direction. The displacements and stresses distributions are compared with the solutions of the finite element method (FEM) and comparison with the corresponding numerical solution indicates that the proposed solution has excellent convergence and accuracy.

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