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1
Content available On propagation of Rayleigh type surface wave in five different theories of thermoelasticity
Singh B., Verma S.
International Journal of Applied Mechanics and Engineering
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2019
|
Vol. 24, no. 3
661--673
EN
The governing equations for a homogeneous and isotropic thermoelastic medium are formulated in the context of coupled thermoelasticity, Lord and Shulman theory of generalized thermoelasticity with one relaxation time, Green and Lindsay theory of generalized thermoelasticity with two relaxation times, Green and Nagdhi theory of thermoelasticity without energy dissipation and Chandrasekharaiah and Tzou theory of thermoelasticity. These governing equations are solved to obtain general surface wave solutions. The particular solutions in a halfspace are obtained with the help of appropriate radiation conditions. The two types of boundaries at athe surface of a half-space are considered namely, the stress free thermally insulated boundary and stress free isothermal boundary. The particular solutions obtained in a half-space satisfy the relevant boundary conditions at the free surface of the half-space and a frequency equation for the Rayleigh wave speed is obtained for both thermally insulated and isothermal cases. The non-dimensional Rayleigh wave speed is computed for aluminium metal to observe the effects of frequency, thermal relaxation time and different theories of thermoelasticity.
2
Content available remote Propagation of Rayleigh wave in two-temperature dual-phase-lag thermoelasticity
Singh B., Kumari S., Singh J.
Mechanics and Mechanical Engineering
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2017
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Vol. 21, nr 1
105--116
EN
The governing equations of transversely isotropic dual-phase-lag two-temperature thermoelasticity are solved for the surface wave solutions. The particular solutions in the half-space satisfy the boundary conditions at a thermally insulated /isothermal stress-free surface of a half-space to obtain the frequency equation of the Rayleigh wave for the cases of coupled thermoelasticity, Lord and Shulman thermoelasticity and dual-phase-lag thermoelasticity. Some particular and special cases are obtained. The numerical values of the non-dimensional speed of the Rayleigh wave are computed and shown graphically against frequency, non-dimensional elastic constant and two-temperature parameter. The effects of frequency, two-temperature and dual-phase-lag are observed on the nondimensional speed of Rayleigh wave.
3
Content available Phase velocity and attenuation of longitudinal shear vibrations of hollow poroelastic cylinders
Ahmed Shah S., Javvad Hussaini S.
International Journal of Applied Mechanics and Engineering
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2014
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Vol. 19, no. 2
337--346
EN
The present paper is devoted to the study of phase velocity and attenuation of longitudinal shear vibrations of hollow poroelastic circular cylinders in the presence of dissipation. The explicit expressions for phase velocity and attenuation of longitudinal shear vibrations are derived. The frequency equation of longitudinal shear vibrations and modes obtained in a previous paper are used to compute the phase velocity and attenuation for different dissipations for thin and thick poroelastic cylindrical shells and poroelastic solid cylinder. The physical parameters of sandstone saturated with kerosene and sandstone saturated with water are used for the purpose of computation. It is found that the phase velocity is linear beyond certain frequency. Phase velocity is smaller for a typical anti-symmetric mode compared to the flexural mode. It is greater for the second mode than that of the first mode. Also the phase velocity is larger for a thin poroelastic cylindrical shell than that of a thick poroelastic cylindrical shell. The same is true for attenuation also. Attenuation is very high for the considered dissipations and it increases with the increase in dissipation.
4
Content available On Rayleigh wave in generalized magneto-thermoelastic media with hydrostatic initial stress
Singh B., Kumari S., Singh J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2012
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Vol. 60, nr 2
349-352
EN
The governing equations of generalized magneto-thermoelasticity with hydrostatic initial stress are solved for surface wave solutions. The particular solutions in the half-space are applied to the boundary conditions at the free surface of the half-space to obtain the frequency equation of Rayleigh wave. The frequency equation is approximated for small thermal coupling and small reduced frequency. The velocity of propagation and amplitude-attenuation factor of Rayleigh wave are computed numerically for a particular material. Effects of magnetic field and hydrostatic initial stress on the velocity of the propagation and amplitude-attenuation factor are shown graphically.
5
Content available Study of circular crested waves in a micropolar porous medium possessing cubic symmetry
Kumar R., Panchal M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2011
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Vol. 59, nr 1
103-110
EN
The paper is concerned with the propagation of circular crested Lamb waves in a homogeneous micpropolar porous medium possessing cubic symmetry. The frequency equations, connecting the phase velocity with wave number and other material parameters, for symmetric as well as antisymmetric modes of wave propagation are derived. The amplitudes of displacement components, microrotation and volume fraction field are computed numerically. The numerical results obtained have been illustrated graphically to understand the behavior of phase velocity and attenuation coefficient versus wave number of a wave.
6
Content available remote Wave propagation in a micropolar elastic layer sandwiched between liquid haIf-space and mnicropolar solid half-space
Tomar S. K.
International Journal of Applied Mechanics and Engineering
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2007
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Vol. 12, no 1
255-262
EN
A problem of surface waves in a layer of micropolar elastic material overlying a micropolar elastic haIf-space and underlying a liquid haIf-space is studied. The frequency equation is derived, and then solved numerically for particular models. Numerical results show that there exist infinite numbers of modes of propagation. It is found that the surface waves are dispersive for all modes of propagation except the lowest one, which is almost non-dispersive. The numericaI results obtained are presented graphicaIly.
7
Propagation of Rayleigh waves over a thermo-viscoelastic half space with a slightly curved free space
Pal P. Ch., Kumar L.
Acta Geophysica Polonica
|
1999
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Vol. 47, nr 4
363-373
EN
Propagation of Rayleigh waves over a thermo-viscoelastic half space with a slightly curved (cylindrical) free space is considered. It is shown that, like in the case of curved elastic space, the surface displacement components and the temperature for the curved thermo-viscoelastic half space can be expressed in terms of the corresponding quantities in a plane-faced half space with a unit surface line source. Expressions for corrections to the Rayleigh wave displacements due to the curvature are obtained. Some special cases are also derived, and solution of frequency equation is considered. The roots of frequency equations are obtained approximately and numerical results are obtained.
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