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Journal ArticleDOI

Effect of fractional parameter on plane waves in a rotating elastic medium under fractional order generalized thermoelasticity

26 Nov 2012-International Journal of Applied Mechanics (Imperial College Press)-Vol. 04, Iss: 03, pp 1250030
TL;DR: In this article, a two-dimensional generalized thermoelastic coupled problem for a homogeneous isotropic and thermally conducting rotating medium in the context of the above fractional order generalized thermelasticity with two relaxation time parameters is considered.
Abstract: In ["Theory of fractional order generalized thermoelasticity," Journal of Heat Transfer132, 2010] Youssef has proposed a model in generalized thermoelasticity based on the fractional order time derivatives. The current manuscript is concerned with a two-dimensional generalized thermoelastic coupled problem for a homogeneous isotropic and thermally conducting thermoelastic rotating medium in the context of the above fractional order generalized thermoelasticity with two relaxation time parameters. The normal mode analysis technique is used to solve the resulting non-dimensional coupled governing equations of the problem. The resulting solution is then applied to two concrete problems. The effect of the fractional parameter and the time instant on the variations of different field quantities inside the elastic medium are analyzed graphically in the presence of rotation.
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Cites background from "Effect of fractional parameter on p..."

  • ...Sarkar and Lahiri [14] researched the two-dimensional dynamic problem considering fractional order parameters....

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  • ...34, 724–739 (2011) [14] Sarkar, N., Lahiri, A.: Effect of fractional parameter on plane waves in a rotating elastic medium under fractional order generalized ther- moelasticity....

    [...]

References
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Journal ArticleDOI
TL;DR: In this paper, a linear dissipative mechanism whose Q is almost frequency independent over large frequency ranges has been investigated by introducing fractional derivatives in the stressstrain relation, and a rigorous proof of the formulae to be used in obtaining the analytic expression of Q is given.
Abstract: Summary Laboratory experiments and field observations indicate that the Q of many non-ferromagnetic inorganic solids is almost frequency independent in the range 10-2-107 cis, although no single substance has been investigated over the entire frequency spectrum. One of the purposes of this investigation is to find the analytic expression for a linear dissipative mechanism whose Q is almost frequency independent over large frequency ranges. This will be obtained by introducing fractional derivatives in the stressstrain relation. Since the aim of this research is also to contribute to elucidating the dissipating mechanism in the Earth free modes, we shall treat the dissipation in the free, purely torsional, modes of a shell. The dissipation in a plane wave will also be treated. The theory is checked with the new values determined for the Q of spheroidal free modes of the Earth in the range between 10 and 5 min integrated with the Q of Rayleigh waves in the range between 5 and 0.6 min. Another check of the theory is made with the experimental values of the Q of the longitudinal waves in an aluminium rod in the range between lo-’ and 10-3s. In both checks the theory represents the observed phenomena very satisfactorily. The time derivative which enters the stress-strain relation in both cases is of order 0.15. The present paper is a generalized version of another (Caputo 1966b) in which an elementary definition of some differential operators was used. In this paper we give also a rigorous proof of the formulae to be used in obtaining the analytic expression of Q; moreover, we present two checks of the theory with experimental data. The present paper is a generalized version of another (Caputo 1966b) in which an elementary definition of some differential operators was used. In this paper we give also a rigorous proof of the formulae to be used in obtaining the analytic expression of Q; moreover, we present two checks of the theory with experimental data. In a homogeneous isotropic elastic field the elastic properties of the substance are specified by a description of the strains and stresses in a limited portion of the field since the strains and stresses are linearly related by two parameters which describe the elastic properties of the field. If the elastic field is not homogeneous nor isotropic the properties of the field are specified in a similar manner by a larger number of parameters which also depend on the position.

3,372 citations

Journal ArticleDOI
TL;DR: In this article, a unified treatment of thermoelasticity by application and further developments of the methods of irreversible thermodynamics is presented, along with a new definition of the dissipation function in terms of the time derivative of an entropy displacement.
Abstract: A unified treatment is presented of thermoelasticity by application and further developments of the methods of irreversible thermodynamics. The concept of generalized free energy introduced in a previous publication plays the role of a ``thermoelastic potential'' and is used along with a new definition of the dissipation function in terms of the time derivative of an entropy displacement. The general laws of thermoelasticity are formulated in a variational form along with a minimum entropy production principle. This leads to equations of the Lagrangian type, and the concept of thermal force is introduced by means of a virtual work definition. Heat conduction problems can then be formulated by the methods of matrix algebra and mechanics. This also leads to the very general property that the entropy density obeys a diffusion‐type law. General solutions of the equations of thermoelasticity are also given using the Papkovitch‐Boussinesq potentials. Examples are presented and it is shown how the generalized coordinate method may be used to calculate the thermoelastic internal damping of elastic bodies.

2,287 citations

Journal ArticleDOI
01 Apr 1971

726 citations

Journal ArticleDOI
TL;DR: The model of dissipation based on memory introduced by Caputo is generalized and checked with experimental dissipation curves of various materials.
Abstract: The model of dissipation based on memory introduced by Caputo is generalized and checked with experimental dissipation curves of various materials

725 citations

Journal ArticleDOI
TL;DR: A quasi-static uncoupled theory of thermoelasticity based on the heat conduction equation with a time-fractional derivative of order α is proposed in this article.
Abstract: A quasi-static uncoupled theory of thermoelasticity based on the heat conduction equation with a time-fractional derivative of order α is proposed. Because the heat conduction equation in the case 1≤α≤2 interpolates the parabolic equation (α = 1) and the wave equation (α = 2), the proposed theory interpolates a classical thermoelasticity and a thermoelasticity without energy dissipation introduced by Green and Naghdi. The Caputo fractional derivative is used. The stresses corresponding to the fundamental solutions of a Cauchy problem for the fractional heat conduction equation are found in one-dimensional and two-dimensional cases.

482 citations