scholarly journals Buckling of a composite bar made of a functional-gradient material with an inhomogeneous pre-stress field

2018 ◽  
Vol 226 ◽  
pp. 01014
Author(s):  
Vadim V. Eremeev ◽  
Denis V. Ivashchenko
Keyword(s):  
Stress Field ◽  
Circular Cylinder ◽  
Nonlinear Elasticity ◽  
Linear Instability ◽  
Initial Stresses ◽  
Gradient Material ◽  
Material Inhomogeneity ◽  
Functional Gradient ◽  
Functional Gradient Material ◽  
Graded Material

Within the 3D nonlinear elasticity we discuss the linear instability of a composite bar made of a functially graded material and having initial stresses. The bar consists of two layers which are inflated for a annular wedge of a circular cylinder. We present the linearized boundary0value problem and obtain its non-trivial solutions. The influence of the material inhomogeneity and the initial stresses are discussed.

scholarly journals ON THE LOSS OF STABILITY OF A TWO-LAYERED PLATE MADE OF A FUNCTIONAL-GRADIENT MATERIAL WITH A NON-UNIFORM FIELD OF PRE-STRESSES

2019 ◽  
Vol 81 (4) ◽  
pp. 513-520
Author(s):  
V.V. Eremeev
Keyword(s):  
Constitutive Relation ◽  
Linear Instability ◽  
Functionally Graded ◽  
Initial Stresses ◽  
Gradient Material ◽  
Internal Stresses ◽  
Uniform Field ◽  
Loss Of Stability ◽  
Material Inhomogeneity ◽  
Functional Gradient Material

In the framework of three-dimensional nonlinear elasticity we consider linear instability of a composite plate made of functionally graded material and having initial stresses. The plae consists of two layers which were obtained as a result of flattening of an annual sector of an elastic cylinder. This deformation results in appearance of internal stresses. Thus, the plate becomes initially stressed. The initial stresses depend on the thickness coordinate, so we get inhomogeneous stress field. We have two types of inhomogeneities, the first is the inhomogeneity of the initial stresses whereas the second is the material inhomogeneity.We use the incompressible neo-Hookean material model as a constitutive relation. Despite of relatively simple form this model describes properly severe deformations of some rubber-like materials. For incompressible materials the flattening constitutes one of the so-called universal deformations, that is such deformation which is independent on the choice of constitutive relation. The material inhomogeneity is described through a dependence of the shear modulus on the thickness coordinate. Such inhomogeneity could be related to the manufacturing of the material or to further treatment. The stability was analysed using the linearization approach. We superimpose infinitesimal deformations on the finite initial one. The linearized boundary-value problem was derived and its nontrivial solutions were obtained. The solution was obtained in series of trigonometric functions. This helps to automatically satisfy a part of boundary conditions. We consider the influence of the inhomogeneity and initial stresses. We show that the initial stresses may significantly change critical deformations. For example, the loss of stability is possible due to initial stresses only.

scholarly journals ON THE LOSS OF STABILITY OF A TWO-LAYERED PLATE MADE OF A FUNCTIONAL-GRADIENT MATERIAL WITH A NON-UNIFORM FIELD OF PRE-STRESSES

2019 ◽  
Vol 81 (4) ◽  
pp. 512-518
Author(s):  
V.V. Eremeev
Keyword(s):  
Constitutive Relation ◽  
Linear Instability ◽  
Functionally Graded ◽  
Initial Stresses ◽  
Gradient Material ◽  
Internal Stresses ◽  
Uniform Field ◽  
Loss Of Stability ◽  
Material Inhomogeneity ◽  
Functional Gradient Material

In the framework of three-dimensional nonlinear elasticity we consider linear instability of a composite plate made of functionally graded material and having initial stresses. The plae consists of two layers which were obtained as a result of flattening of an annual sector of an elastic cylinder. This deformation results in appearance of internal stresses. Thus, the plate becomes initially stressed. The initial stresses depend on the thickness coordinate, so we get inhomogeneous stress field. We have two types of inhomogeneities, the first is the inhomogeneity of the initial stresses whereas the second is the material inhomogeneity.We use the incompressible neo-Hookean material model as a constitutive relation. Despite of relatively simple form this model describes properly severe deformations of some rubber-like materials. For incompressible materials the flattening constitutes one of the so-called universal deformations, that is such deformation which is independent on the choice of constitutive relation. The material inhomogeneity is described through a dependence of the shear modulus on the thickness coordinate. Such inhomogeneity could be related to the manufacturing of the material or to further treatment. The stability was analysed using the linearization approach. We superimpose infinitesimal deformations on the finite initial one. The linearized boundary-value problem was derived and its nontrivial solutions were obtained. The solution was obtained in series of trigonometric functions. This helps to automatically satisfy a part of boundary conditions. We consider the influence of the inhomogeneity and initial stresses. We show that the initial stresses may significantly change critical deformations. For example, the loss of stability is possible due to initial stresses only.

scholarly journals Dynamic Fracture Analysis of Functional Gradient Material Coating Based on the Peridynamic Method

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 62 ◽  
Author(s):  
Yu Zhang ◽  
Zhanqi Cheng ◽  
Hu Feng
Keyword(s):  
Elastic Modulus ◽  
Crack Propagation ◽  
Dynamic Fracture ◽  
Gradient Material ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Functional Gradient ◽  
Damage And Failure ◽  
Functional Gradient Material ◽  
Graded Material

Functional gradient materials (FGMs) have tremendous potential due to their characteristic advantage of asymptotic continuous variation of their properties. When an FGM is used as a coating material, damage and failure of the interface with the substrate component can be effectively inhibited. In order to study the dynamic crack propagation in FGM coatings, a new method, peridynamics (PD), was used in the present study to simulate dynamic fractures of FGM coatings bonded to a homogeneous substrate under dynamic loading. The bond-based PD theory was employed to study crack propagation and branching in the FGM coating. The influences of the coating gradient pattern, loading, and the geometry and size of the structure on crack curving and propagation under impact loading were investigated. The numerical results show that different forms of the elastic modulus of graded material, the geometry of the structure, and the loading conditions have considerate effects on crack propagation in FGM coatings, but a specific form of elastic modulus had a limited effect on the dynamic fracture of FGM coating.

System Development of Processing Functional Gradient Material Part by Laser Rapid Prototyping

2013 ◽  
Vol 834-836 ◽  
pp. 1571-1574
Author(s):  
Qun Qin ◽  
Guang Xia Chen
Keyword(s):  
Path Planning ◽  
System Development ◽  
One Dimension ◽  
Gradient Material ◽  
Two Dimension ◽  
Functional Gradient ◽  
Stl File ◽  
Functional Gradient Material ◽  
Planning Methods ◽  
Material Information

The primary goal of this research is the development of software system about functional gradient material process by laser. The system can be divided into several modules such as STL file loading and viewing, model slicing, filling path planning and process controlling. Path planning of FGM area is one key technology of system development because of one path must contain material information of functional gradient material. The material information planning methods of one-dimension and two-dimension functional gradient material were described respectively in this article. The material information of one-dimension FGM changes by layer along Z-axis, and the material information of two-dimension FGM changes by path in X-Y plane, especially, there is different change direction of FGM between inner loop and outer loop.

Fabrication of Functional Gradient Materials Electrode and its Application in Micro-EDM

2017 ◽  
Vol 868 ◽  
pp. 151-157
Author(s):  
Xiao Peng Li ◽  
Yuan Gang Wang ◽  
Fu Ling Zhao ◽  
Meng Hua Wu
Keyword(s):  
Electrical Discharge Machining ◽  
Gradient Material ◽  
Homogeneous Material ◽  
Tool Electrode ◽  
Micro Edm ◽  
Gradient Materials ◽  
Functional Gradient ◽  
Micro Electrical Discharge Machining ◽  
Functional Gradient Material ◽  
Edm Process

The concept and the primary preparation method of functional gradient materials are described in this paper. Functional gradient material is prepared as a tool electrode by electrochemical method and its performance is further tested in the micro electrical discharge machining (micro-EDM) experiments. Compared with the homogeneous material electrode, the functional gradient material electrode can effectively inhibit the wearing of the tool electrode and improve the distribution trend of current density during the micro-EDM process. The results disclose the prospects for functional gradient material to be used as tool electrode in the micro-EDM process.

Fabrication of (TiB2-Fe)/Fe Functional Gradient Material by SHS/QP

2003 ◽  
Vol 249 ◽  
pp. 105-108 ◽  
Author(s):  
Zheng Yi Fu ◽  
J.P. Liu ◽  
Jin Yong Zhang ◽  
Qing Jie Zhang
Keyword(s):  
Gradient Material ◽  
Functional Gradient ◽  
Functional Gradient Material

scholarly journals STRESS CONCENTRATION IN A HOMOGENEOUS PLATE WITH A CIRCULAR HOLE REINFORCED BY AN INCLUSION FROM A FUNCTIONAL-GRADIENT MATERIAL

2021 ◽  
pp. 110-115
Author(s):  
Eteri Hart ◽  
Terokhin Bohdan
Keyword(s):  
Elastic Modulus ◽  
Stress Concentration ◽  
Circular Hole ◽  
Strain State ◽  
Isotropic Plate ◽  
Gradient Material ◽  
Homogeneous Material ◽  
Functional Gradient ◽  
Homogeneous Plate ◽  
Functional Gradient Material

Computer simulation of the stress-strain state of a thin rectangular homogeneous isotropic plate with a circular hole, reinforced by an annular inclusion made of a functional-gradient material (FGM) has been carried out. The influence of the geometric (width) and mechanical (elastic modulus) parameters of the inclusion is investigated when various laws of change in the elastic modulus of the FGM are set on the stress concentration around the hole. Recommendations for the use of inclusions are given. If there is a "hard" annular inclusion in a homogeneous plate with a hole, it is expedient to use an FGM with a nonlinear law of change in the modulus of elasticity in comparison with an inclusion made of a homogeneous material. Despite the fact that the inclusion leads to a slight increase in the stress concentration factor in comparison with a homogeneous material, it makes it possible to increase the rigidity of the system as a whole. The width of FGM inclusions affects the nature of the stress distribution: the wider the inclusion, the more smoothly the stress redistribution in the main matrix occurs.

Microstructure and Mechanical Properties of Ti(C,N)-based Functional Gradient Cermets Nitriding by Microwave Heating

2015 ◽  
Vol 34 (5) ◽  
Author(s):  
Siwen Tang ◽  
Deshun Liu ◽  
Pengnan Li ◽  
Yuqiang Chen ◽  
Xiong Xiao
Keyword(s):  
Microwave Heating ◽  
Eutectic Temperature ◽  
Titanium Carbonitride ◽  
Gradient Material ◽  
Face Centered Cubic ◽  
Functional Gradient ◽  
Comprehensive Properties ◽  
Sintering Time ◽  
Functional Gradient Material ◽  
Face Centered

AbstractThe interaction between nitrogen and titanium carbonitride (Ti(C,N))-based cermets by microwave heating was applied to develop functional gradient cermets. Ti(C,N)-based cermets was densification and nitrided simultaneously above the eutectic temperature, which greatly shortens the sintering time. Experimental results show that a face centered cubic (fcc) rich surface layer was formed at the surface of the cermets. Meanwhile, a new three layers core/rim structure was found in the cermets and its formation mechanism was proposed in this study. The functional gradient material exhibits excellent comprehensive properties.

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