Functionally Graded Biocomposites

2012 ◽  
Vol 706-709 ◽  
pp. 693-698 ◽  
Author(s):  
Mohamad Reza Barzegari ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Behavior ◽  
Low Cost ◽  
Strength Properties ◽  
Natural Fibre ◽  
Functionally Graded ◽  
Gradual Change ◽  
Graded Materials ◽  
Property Variation ◽  
Functionally Graded Composite ◽  
Natural Wood

Functionally graded materials (FGM) are characterized by a gradual change in the volume fractions of two or more components as a function of position along certain dimensions. FGM has been introduced as an alternative to laminated composites where a mismatch in properties across each layer interface is the origin of stress concentration and a source of delamination/failure. In addition, the use of natural wood fibres as reinforcement has the advantage of easy manufacturing, low cost, biodegradability, negligible health hazards and high specific properties. Using short fibres in a controlled manner to produce functionally graded composites can provide more balanced properties and lead to improved stiffness/strength properties across thickness. The aim of this paper is to evaluate the mechanical behavior of functionally graded natural fibre composites. To study the effect of composite property variation, the functionally graded composite is divided into a number of homogeneous layers in order to evaluate the mechanical behavior. In particular, the effect wood fibre content variation across thickness on the tensile properties of the composites is presented.

scholarly journals On the Finite Element Implementation of Functionally Graded Materials

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 287 ◽  
Author(s):  
Emilio Martínez-Pañeda
Keyword(s):  
Finite Element ◽  
Functionally Graded Materials ◽  
Functionally Graded ◽  
The Finite Element Method ◽  
Element Level ◽  
Graded Materials ◽  
Property Variation ◽  
User Subroutine ◽  
Finite Element Package ◽  
Fracture Assessment

We investigate the numerical implementation of functionally graded properties in the context of the finite element method. The macroscopic variation of elastic properties inherent to functionally graded materials (FGMs) is introduced at the element level by means of the two most commonly used schemes: (i) nodal based gradation, often via an auxiliary (non-physical) temperature-dependence, and (ii) Gauss integration point based gradation. These formulations are extensively compared by solving a number of paradigmatic boundary value problems for which analytical solutions can be obtained. The nature of the notable differences revealed by the results is investigated in detail. We provide a user subroutine for the finite element package ABAQUS to overcome the limitations of the most popular approach for implementing FGMs in commercial software. The use of reliable, element-based formulations to define the material property variation could be key in fracture assessment of FGMs and other non-homogeneous materials.

An Analysis of Thermo-Mechanical Behavior in a Multilayer Composite Pipe Under Temperature Variation

2010 ◽  
Author(s):  
Wei Yang ◽  
Jyhwen Wang
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Analytical Solution ◽  
Mechanical Behavior ◽  
Temperature Change ◽  
Thermal Stresses ◽  
Element Model ◽  
Functionally Graded ◽  
Element Analysis ◽  
Graded Materials

A generalized analytical solution of mechanical and thermal induced stresses in a multi-layer composite cylinder is presented. Based on the compatibility condition at the interfaces, an explicit solution of mechanical stress due to inner and outer surface pressures and thermal stress due to temperature change is derived. A finite element model is also developed to provide the comparison with the analytical solution. It was found that the analytical solutions are in good agreement with finite element analysis result. The analytical solution shows the non-linear dependency of thermal stress on the diameters, thicknesses and the material properties of the layers. It is also shown that the radial and circumferential thermal stresses depend linearly on the coefficients of thermal expansion of the materials and the temperature change. As demonstrated, this solution can also be applied to analyze the thermo-mechanical behavior of pipes coated with functionally graded materials.

Effect of Disc Geometry on the Steady State Creep in a Rotating Disc Made of Functionally Graded Materials

2012 ◽  
Vol 736 ◽  
pp. 183-191 ◽  
Author(s):  
Manish Garg ◽  
B.S. Salaria ◽  
V.K. Gupta
Keyword(s):  
Steady State ◽  
Creep Behaviour ◽  
Pure Aluminum ◽  
Functionally Graded ◽  
Steady State Creep ◽  
Strain Rates ◽  
Rotating Disc ◽  
Graded Materials ◽  
Functionally Graded Composite ◽  
Silicon Carbide Particles

The steady state creep behaviour of a rotating FGM disc having linearly varying thickness has been investigated. The disc is assumed to be made of functionally graded composite containing non-linearly varying radial distribution of silicon carbide particles in a matrix of pure aluminum. The creep behaviour of the composite has been described by threshold stress based law. The effect of varying the disc thickness gradient has been analyzed on the stresses and strain rates in the FGM disc. It is observed that the radial and tangential stresses induced in the FGM disc decrease throughout with the increase in thickness gradient of the disc. The strain rates also decrease with the increase in thickness gradient of the FGM disc, with a relatively higher decrease near the inner radius. The increase in disc thickness gradient results in relatively uniform distribution of strain rates and hence reduces the chances of distortion in the disc.

Biomimetic Functionally Graded Materials: Synthesis by Impeller-Dry-Blending

2009 ◽  
Vol 3 ◽  
pp. 37-49 ◽  
Author(s):  
D.T. Chavara ◽  
Cyndi X. Wang ◽  
Andrew Ruys
Keyword(s):  
Functionally Graded Materials ◽  
Low Cost ◽  
Functionally Graded ◽  
Orthopaedic Implant ◽  
Materials Synthesis ◽  
Mollusc Shell ◽  
Graded Materials ◽  
Commercial Viability ◽  
Graded Material ◽  
Concentration Changes

Functionally graded materials (FGMs) can be found naturally in many biological structures, for example bamboo and the mollusc shell. They are defined as having a compositional or microstructural gradient, for example the gradation in fibre content in bamboo stems. A continuous bulk functionally graded material has the potential to be an ideal orthopaedic implant for load bearing applications. Due to the fabrication complexities involved in the production of these continuous bulk functionally graded materials, commercialisation and fabrication are still proving to be a challenge to researchers worldwide. This paper presents an overview of the redesigned novel commercially viable process known as the Impeller-Dry-Blending (IDB) process. Results presented in this paper of fabricated functionally graded materials illustrate the potential of IDB to produce continuous bulk functionally graded materials consisting of either compositional or porosity concentration changes. The successful fabrication of these continuous bulk functionally graded materials at such a low cost clearly demonstrates the commercial viability of the IDB process.

FE modeling of creep in linear and non-linear FGM cylinder under internal pressure

2014 ◽  
Vol 10 (1) ◽  
pp. 94-105
Author(s):  
Manish Garg ◽  
Dharmpal Deepak ◽  
V.K. Gupta
Keyword(s):  
Creep Behavior ◽  
Outer Radius ◽  
Functionally Graded ◽  
Composite Cylinder ◽  
Linear Distribution ◽  
Graded Materials ◽  
Content Type ◽  
Functionally Graded Composite ◽  
Non Linear ◽  
Creep Strains

Purpose – The purpose of this paper is to investigate creep in an internally pressurized thick-walled, closed ends cylinder made of functionally graded composite, having linear and non-linear distribution of reinforcement, using finite element (FE) analysis. Design/methodology/approach – FE-based Abaqus software is used to investigate creep behavior of a functionally graded cylinder. The cylinder is made of composite containing linear and non-linearly varying distributions of reinforcement along the radius. The creep behavior has been described by Norton's power law. The creep stresses and strains have been estimated in linear and non-linear functionally graded materials (FGM) cylinders and compared with those estimated for a similar composite cylinder but having uniform distribution of reinforcement. Findings – The radial stress in the composite cylinder is observed to decreases over the entire radius upon imposing linear or non-linear reinforcement gradients. However, the tangential stress in the cylinder increases near the inner radius but decreases toward the outer radius, on imposing linear or non-linear reinforcement gradients. The creep strains in the FGM cylinders are significantly lower than those observed in a uniform composite cylinder. Originality/value – The creep strains in an internally pressurized functionally graded thick composite cylinder could be reduced significantly by employing non-linear distribution of reinforcement along the radial direction.

scholarly journals Call for papers on special issue “Advances in additive manufacturing: modeling, design, and application”

2020 ◽  
Vol 2 (1) ◽  
pp. 048-048
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Industry ◽  
Low Cost ◽  
Functionally Graded ◽  
Layer By Layer ◽  
Special Issue ◽  
High Quality Research ◽  
Graded Materials ◽  
3D Printers ◽  
New Applications

Aim & Scope: Additive Manufacturing (AM) is revolutionizing the manufacturing industry. Building parts layer by layer makes fabrication of geometries which were impossible otherwise. Freedom of fabrication, rapid and low-cost prototyping, and reduction in material waste are only a few of advantages that AM offers to many industries from biomedical to aeronautics. Hence, AM is getting lots of interest over the past few years. These combined with lower cost of 3d printers is making this pace even faster. To keep up with the advancements in AM, this special issue aims to publish high quality research articles in the field of additive manufacturing and its related topics. This includes but not limited to alloy design for AM, new AM technologies and process optimization, process-microstructure-property, characterization of AM parts, modeling AM processes, topology optimization, fatigue, fracture, and failure analysis, tailoring properties, and functionally graded materials through AM. New applications are welcome, as well. We kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.

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