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1

A Modified Kerner Model to Predict the Thermal Expansion Coefficient of Multi-Phase Reinforced Composites Al6092/SiC/LAS

Zhang Shihao, Hou Qinglin, Jiang H.Y.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 4

1327--1332

EN

In this work, a new supplementary formula was introduced to modify the Kerner model. This supplementary formula enable the Kerner model to predict the thermal expansion coefficient of multi-phase reinforced composites by normalization of the thermal expansion coefficient, bulk modulus, and shear modulus of the reinforcements. For comparison, the modified Kerner model as well as modified Schapery, the rule of mixtures, and Turner models were used to predict the thermal expansion coefficient of multi-phase reinforced composites 6092 Aluminum Alloy/silicon carbide/β-eucryptite. The results confirm the robustness of the modified Kerner model for predicting the thermal expansion coefficient of composites with multi-phase near-spherical inclusions. It may provide a fine selection to predict the thermal expansion coefficient of multi-phase reinforced metal matrix composites which cannot predict efficiently before.

2

Two-dimensional analysis of functionally graded thermoelastic microelongated solid

Sharma Anchal, Ailawalia Praveen

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 4

155--169

EN

The present research focuses on two-dimensional deformation in a functionally graded thermoelastic micro-elongated medium. It is supposed that the non-homogeneous properties (thermal and mechanical) of FGM are in the x-direction. The normal mode technique is used to acquire the analytic expression for displacement components, stress, micro-elongation and temperature. The cause and effect relationship of non-homogeneity and physical quantities is shown through graphical results.

3

Axisymmetric thermoelastic analysis of long cylinder made of FGM reinforced by aluminum and silicone carbide using DQM

Saeedi S., Kholdi M., Loghman A., Ashrafi H., Arefi M.

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e48, 2022

EN

In this study, the thermoelastic stress analysis of a thick-walled cylinder made of functionally graded material (FGM) is investigated. The FGM is assumed a mixture of aluminum and silicone carbide in which the effective material properties are estimated through modified mixture law. Temperature distribution is obtained using the solution of one-dimensional heat transfer equation with the assumption of boundary condition. Solution procedure is developed based on the differential quadrature method. Effect of FGM characteristics such as percentages of ceramic particles at the outer side of cylinder's wall, and power of ceramic particles distribution, on the distribution of stress components, and temperature along the thickness are presented. In addition, stress distribution arising from the thermomechanical loading on structure, along the thickness are is investigated. Verification of the method, formulation and solution procedure is confirmed through comparison with available results in literature.

4

Two dimensional deformation of a multilayered thermoelastic half-space due to surface loads and heat source

Vashishth A. K., Rani K., Singh K.

International Journal of Applied Mechanics and Engineering

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2020

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Vol. 25, no. 1

177--197

EN

This article deals with a 2-D problem of quasi-static deformation of a multilayered thermoelastic medium due tovsurface loads and heat source. The propagator matrix is obtained for the multilayered formalism of thermoelastic layers. Analytical solutions, in terms of the displacements, stresses, heat flux and temperature function, are obtained for normal strip and line loads, shear strip and line loads and strip and line heat sources. Numerical computation of the obtained analytical expressions is also done. The effects of layering have been studied. For the verification of the results, results of earlier studies have been obtained as particular cases of the present study.

5

A general study of fundamental solutions in aniotropicthermoelastic media with mass diffusion and voids

Chawla Vijay, Kamboj Deepmala

International Journal of Applied Mechanics and Engineering

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2020

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Vol. 25, no. 4

22--41

EN

The present paper deals with the study of a fundamental solution in transversely isotropic thermoelastic media with mass diffusion and voids. For this purpose, a two-dimensional general solution in transversely isotropic thermoelastic media with mass diffusion and voids is derived first. On the basis of the obtained general solution, the fundamental solution for a steady point heat source on the surface of a semi-infinite transversely isotropic thermoelastic material with mass diffusion and voids is derived by nine newly introduced harmonic functions. The components of displacement, stress, temperature distribution, mass concentration and voids are expressed in terms of elementary functions and are convenient to use. From the present investigation, some special cases of interest are also deduced and compared with the previous results obtained, which prove the correctness of the present result.

6

On wave propagation in a random micropolar generalized thermoelastic medium

Mitra M., Bhattacharyya R. K.

Archives of Thermodynamics

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2017

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Vol. 38, no. 2

21--60

EN

This paper endeavours to study aspects of wave propagation in a random generalized-thermal micropolar elastic medium. The smooth perturbation technique conformable to stochastic differential equations has been employed. Six different types of waves propagate in the random medium. The dispersion equations have been derived. The effects due to random variations of micropolar elastic and generalized thermal parameters have been computed. Randomness causes change of phase speed and attenuation of waves. Attenuation coefficients for high frequency waves have been computed. Second moment properties have been briefly discussed with application to wave propagation in the random micropolar elastic medium. Integrals involving correlation functions have been transformed to radial forms. A special type of generalized thermo-mechanical auto-correlation functions has been used to approximately compute effects of random variations of parameters. Uncoupled problem has been briefly outlined.

7

Boundary integral equations for an anisotropic bimaterial with thermally imperfect interface and internal inhomogeneities

Sulym H., Pasternak I., Tomashivskyy M.

Acta Mechanica et Automatica

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2016

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Vol. 10, no. 1

66--74

EN

This paper studies a thermoelastic anisotropic bimaterial with thermally imperfect interface and internal inhomogeneities. Based on the complex variable calculus and the extended Stroh formalism a new approach is proposed for obtaining the Somigliana type integral formulae and corresponding boundary integral equations for a thermoelastic bimaterial consisting of two half-spaces with different thermal and mechanical properties. The half-spaces are bonded together with mechanically perfect and thermally imperfect interface, which model interfacial adhesive layers present in bimaterial solids. Obtained integral equations are introduced into the modified boundary element method that allows solving arbitrary 2D thermoelacticity problems for anisotropic bimaterial solids with imperfect thin thermo-resistant interfacial layer, which half-spaces contain cracks and thin inclusions. Presented numerical examples show the effect of thermal resistance of the bimaterial interface on the stress intensity factors at thin inhomogeneities.

8

Time-dependent thermo-elastic creep analysis of thick-walled spherical pressure vessels made of functionally graded materials

Kashkoli M. D., Nejad M. Z.

Journal of Theoretical and Applied Mechanics

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2015

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Vol. 53 nr 4

1053--1065

EN

Assuming that the thermo-elastic creep response of the material is governed by Norton’s law and material properties, except Poisson’s ratio, are considered as a function of the radius of the spherical vessel, an analytical solution is presented for calculation of stresses and displacements of axisymmetric thick-walled spherical pressure vessels made of functionally graded materials. This analytical solution could be used to study the time and temperature dependence of stresses in spherical vessels made of functionally graded materials. Creep stresses and displacements are plotted against dimensionless radius and time for different values of the powers of the material properties.

9

Weak formulation study for thermoelastic buckling analysis of thick laminated cylindrical shells

Kewei D.

International Journal of Applied Mechanics and Engineering

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2015

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Vol. 20, no. 3

461--470

EN

Weak formulations of mixed state equations of closed laminated cylindrical shells are presented in the Hamilton System. The Hamilton canonical equation of closed cylindrical shell is established. By means of applying the transfer matrix method and taking the advantage of Hamiltonian matrix in the calculation, a unified approach and three-dimensional thermoelastic solutions are obtained for the buckling analysis of closed trick laminated cylindrical shells. All equations of elasticity can be satisfied and all elastic constants can be taken into account. Numerical results are given to compare with those of FEM calculated using SAP5.The principle and method suggested here have clear physical concepts. The equations and boundary conditions proposed in this paper are weakened. The solutions and results given here may serve as a benchmark for other numerical procedures.

10

Quasi-static Planar Deformation in av Medium Composed of Elastic and Thermoelastic Solid Half Spaces Due to Seismic Sources in an Elastic Solid

Vashisth A. K., Rani K., Singh K.

Acta Geophysica

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2015

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Vol. 63, no. 3

605--633

EN

A two-dimensional problem of quasi static deformation of a medium consisting of an elastic half space in welded contact with thermoelastic half space, caused due to seismic sources, is studied. Source is considered to be in the elastic half space. The basic equations, governed by the coupled theory of thermoelasticity, are used to model for thermoelastic half space. The analytical expressions for displacements, strain and stresses in the two half spaces are obtained first for line source and then for dip slip fault. The results for two particular cases, adiabatic conditions and isothermal conditions, are also obtained. Numerical results for displacements, stresses and temperature distribution have also been computed and are shown.

11

New concept of finite element method for FGM materials

Hernik S.

Czasopismo Techniczne. Mechanika

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2010

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R. 107, z. 2-M

99-106

EN

The aim of this paper is new concept of nonhomogeneous finite elements due to FGM composite material. The main idea of functionally graded materials is a smooth variation of material properties, such as modulus of elasticity, coefficient of thermal conductivity or coefficient of thermal expansion, due to continuous change of microstructure. Composite material containing metal or metal alloy as a matrix and ceramic as fibres without FGM interface thin layer may lead to damage or failure due to delamination of the ceramic film from the substrate. This is the result of localized stress gradients at the interface. Classical finite element formulation contains constant material properties, which leads to numerical errors. A proper approach to solve this problem requires application of nonhomogeneous FE containing additional approximation functions in order to interpolate material properties at the level of each finite element. In practice, material shape functions can be represented by exponential or power functions describing individual character of inhomogeneity.

PL

Celem niniejszego artykułu jest prezentacja nowego typu niejednorodnego elementu skończonego służącego do modelowania cienkiej warstwy materiału kompozytowego FGM. Cechą główną materiału FGM (functionally graded materials) jest gładka, funkcyjna zmienność parametrów materiałowych, takich jak moduł Younga, współczynnik rozszerzalności termicznej czy współczynnik przewodności termicznej w zależności od zmiany mikrostruktury. Materiał kompozytowy zawierający metal lub stop metali jako matrycę i materiał ceramiczny jako włókna bez warstwy przejściowej FGM narażony jest na powstawanie lokalnych koncentracji naprężeń na granicach interfejsu. Klasycznie sformułowany element skończony zawiera stałe parametry materiałowe, co prowadzi do znacznych błędów numerycznych. Rozwiązaniem tego problemu jest zastosowanie sformułowania elementu skończonego z dodatkową funkcją aproksymacyjną służącą do interpolacji własności materiałowych na poziomie każdego elementu. W praktyce materiałowe funkcje kształtu są definiowane jako funkcje eksponencjalne lub potęgowe opisujące indywidualny charakter niejednorodności.

12

Effect of hydrostatic initial stress in Green-Naghdi (Type III) thermoelastic half-space subjected to ramp-type heating and loading

Ailawalia P.

Journal of Technical Physics

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2009

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Vol. 50, no 4

403-415

EN

The Green and Naghdi theory of thermoelasticity is employed to study the deformation of thermoelastic solid half-space under hydrostatic initial stresses, subjected to ramp-type heating and loading at the free surface. A linear temperature ramping function is used to more realistically model thermal loading of the half-space surface. The components of displacement, stress arid temperature distribution are obtained in Laplace and Fourier domain by applying integral transforms. These components are then obtained in the physical domain by applying a numerical inversion method. Numerical computations are carried out for a particular example of the model. The results are also presented graphically to show the effect of hydrostatic initial stress and ramping parameter in the medium.

13

Deformation due to inclined load in monoclinic thermoelastic material

Kumar R., Rani L.

International Journal of Applied Mechanics and Engineering

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2008

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Vol. 13, no. 4

923-938

EN

The two-dimensional deformation of homogeneous, thermally conducting monoclinic material as a result of inclined line load is investigated by applying the fourier transform. the inclined load is assumed to be a linear combination of a normal load and a tangential load. the displacements, stresses and temperature distribution so obtained in the physical domain are computed numerically and illustrated graphically. the variations of these quantities have been depicted graphically for a zinc crystal-like material in the coupled thermoelasticity (ct) and uncoupled thermoelasticity (UCT) for an insulated boundary.

14

Inclined Load in Micropolar Thermoelastic Medium Possesing Cubic Symmetry with One Relaxation Time

Kumar R., Ailawalia P.

Mechanics and Mechanical Engineering

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2007

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Vol. 11, nr 1

129-157

EN

The analytic expressions for the displacements, microrotation, stresses and temperature distribution on the free surface of micropolar thermoelastic medium possessing cubic symmetry as a result of inclined load have been obtained. The inclined load is assumed to be a linear combination of a normal load and a tangential load. The Laplace and Fourier transforms have been employed to solve the problem. A special case of moving inclined load has been deduced by making the appropriate changes. The variations of the displacements, microrotation, stresses and temperature distribution with the horizontal distance have been shown graphically for both the problems.

15

Elastodynamics of time harmonic inclined load in micropolar thermoelastic medium possessing cubic symmetry

Kumar R., Ailawalia P.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no. 3

629-644

EN

The analytic expressions for the displacements, microrotation, stresses and temperature distribution on the free surface of a micropolar thermoelastic medium possessing cubic symmetry as a result of time harmonic inclined load have been obtained. The inclined load is assumed to be a linear combination of a normal load and a tangential load. The Fourierer transform has been employed to solve the problem. The variations of the displacements, microrotation, stresses and temperature distribution with the horizontal distance have been shown graphically.

16

Disturbance due to mechanical and thermal sources in orthorhombic thermoelastic material

Kumar R., Rani L.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no. 3

677-692

EN

A dynamical two-dimensional problem of thermoelasticity has been considered to investigate the disturbance due to mechanical (horizontal or vertical) force and thermal source in a homogeneous, thermally conducting orthorhombic material. The Fourier transforms are applied to basic equations to fonn a vector matrix differential equation, which is then solved by eigenvalue approach. The displacements, stresses and temperature distribution so obtained in the physical domain are computed numerically and illustrated graphically. The numerical results of these quantities for the zinc crystal-like material are illustrated to show the comparison for various sources for the theory of coupled thermoelasticity (CT) and uncoupled thermoelasticity (UCT) for an insulated boundary and temperature gradient boundary.

17

Axi-symmetric deformation due to mechanical and thermal sources in a thermoelastic body with voids

Kumar R., Rani L.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no. 2

447-463

EN

In the present investigation, axi-symmetric deformation due to a mechanical and thermal source in a homogeneous, isotropic, thermoelastic half-space with voids has been investigated. An integral transform technique has been used to solve the problem. As an application of the problem (i) continuous normal force (ii) normal force over the circular region (iii) thermal point source (iv) thermal source over the circular region have been considered. The components of displacement, stress, temperature distribution and change in volume fraction field are obtained in the transformed domain and inverted numerically using numerical inversion technique. For a specific model, the effect of voids on these quantities has been depicted graphically.

18

On plane waves in an isotropic linear thermoelastic solid with initial stresses

Singh B.

International Journal of Applied Mechanics and Engineering

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2006

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Vol. 11, no. 4

957-963

EN

The plane wave propagation in a homogenous isotropic, thermally conducting elastic solid under normal initial stresses is studied with two thermal relaxation times. Three types of plane waves, quasi-P, thermal and quasi-SV waves, are shown to exist. The dependence of the velocities of these plane waves on the direction of propagation is shown graphically for different combinations of normal initial stresses.

19

Deformation due to moving loads in thermoelastic body with voids

Kumar R., Rani L.

International Journal of Applied Mechanics and Engineering

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2006

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Vol. 11, no. 1

37-59

EN

The voids effect of loads which are moving at a constant velocity along one of the coordinate axis in a generalized thermoelastic half-space is studied. The analytical expressions of the displacements, stresses, temperature distribution and change in the volume fraction field for two different theories, i.e., Lord-Shulman (L-S), Green-Lindsay (G-L) are obtained by the use of the Fourier transform technique. The integral transform has been inverted by using a numerical technique and numerical results are illustrated graphically for a magnesium crystal-like material for the insulated boundary and temperature gradient boundary.

20

Response of thermoelastic half-space with voids due to inclined load

Kumar R., Rani L.

International Journal of Applied Mechanics and Engineering

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2005

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Vol. 10, no. 2

281-294

EN

A two-dimensional deformation of a homogeneous, isotropic, thermoelastic half-space with voids as a result of an inclined line load is investigated by applying the Laplace and Fourier transforms. The inclined load is assumed to be a linear combination of a normal load and a tangential load. The displacements, stresses, temperature distribution and change in the volume fraction field so obtained in the physical domain are computed numerically. The variations of these quantities have been depicted graphically in the coupled thermoelasticity (CT) and uncoupled thermoelasticity (UCT) for an insulated boundary.