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1
Content available Reflection and transmission in non-local couple stress micropolar thermoelastic media
Gupta Deepa, Malik Sangeeta, Kumar Krishan, Sharma Raj Kumar
International Journal of Applied Mechanics and Engineering
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2022
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Vol. 27, no. 2
53--76
EN
We have studied the problem of homogenous, isotropic non-local couple stress micropolar thermoelastic solid in the absence of body forces, couple density and heat resources. The reflection and transmission of waves at the interface of two distinct media have been investigated. It is observed that amplitude ratios of various reflected and transmitted waves are functions of wave number of incident waves and are affected by the non-local parameter of thermoelastic solid.
2
Content available Influence of diffusion and impedence parameters on wave propagation in thermoelastic medium
Kaushal Sachin, Kumar Rajneesh, Parmar Kulwinder
International Journal of Applied Mechanics and Engineering
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2021
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Vol. 26, no. 4
99--112
EN
The aim of the present paper is to study the impact of diffusion and impedance parameters on the propagation of plane waves in a thermoelastic medium for Green and Lindsay theory (G-L) and the Coupled theory (C-T) of thermoelasticity. Results are demonstrated for impedance boundary conditions and the amplitude ratios of various reflected waves against the angle of incidence are calculated numerically. The characteristics of diffusion, relaxation time and impedence parameter on amplitude ratios have been depicted graphically. Some cases of interest are also derived from the present investigation.
3
Content available Reflection and Transmission of Plane Wave at an Interface Between Two Rotating Micropolar Piezoelectric Solid Half-Spaces
Singh Baljeet, Sangwan Asha, Singh Jagdish
Archives of Acoustics
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2021
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Vol. 46, No. 4
623--635
EN
In this paper, we investigate a problem on reflection and transmission of plane-waves at an interface between two dissimilar half-spaces of a transversely isotropic micropolar piezoelectric material. The entire model is assumed to rotate with a uniform angular velocity. The governing equations of rotating and transversely isotropic micropolar piezoelectric medium are specialized in a plane. Plane-wave solutions of two-dimensional coupled governing equations show the possible propagation of three coupled plane-waves. For an incident plane-wave at an interface between two dissimilar half-spaces, three reflected and three transmitted waves propagate with distinct speeds. The connections between the amplitude ratios of reflected and transmitted waves are obtained. The expressions for the energy ratios of reflected and transmitted waves are also obtained. A numerical example of the present model is considered to illustrate the effects of rotation on the speeds and energy ratios graphically.
4
Content available Study of axi-symmetric vibrations in a micropolar transversely isotropic layer
Gupta R. R., Gupta R. R.
International Journal of Applied Mechanics and Engineering
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2019
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Vol. 24, no. 2
259--268
EN
The present investigation deals with the propagation of circular crested Lamb waves in a homogeneous micropolar transversely isotropic medium. Secular equations for symmetric and skew-symmetric modes of wave propagation in completely separate terms are derived. The amplitudes of displacements and microrotation are computed numerically for magnesium as a material and the dispersion curves, amplitudes of displacements and microrotation for symmetric and skew-symmetric wave modes are presented graphically to evince the effect of anisotropy. Some special cases of interest are also deduced.
5
Content available Investigation of waves generated in transversely isotropic micropolar generalized thermoelastic half space under temperature dependent properties
Gupta R. R., Gupta R. R.
International Journal of Applied Mechanics and Engineering
|
2019
|
Vol. 24, no. 4
53--65
EN
The present study deals with the propagation of waves in a transversely isotropic micropolar generalized thermoelastic material possessing temperature dependent elastic properties. After developing the solution for LS, GL and CT theory, the phase velocities and attenuation quality factor have been obtained. The expressions for amplitudes of stresses, displacements, microratation and temperature distribution have been derived and computed numerically. The numerically evaluated results have been plotted graphically. Some particular cases of interest have also been obtained.
6
Content available remote Reflection of plane waves from surface of a generalized thermo-viscoelastic porous solid half-space with impedance boundary conditions
Singh B.
Mechanics and Mechanical Engineering
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2018
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Vol. 22, nr 4
1483--1496
EN
A phenomenon of reflction of plane waves from a thermally insulated surface of a solid half-space is studied in context of Lord-Shulman theory of generalized thermo-viscoelasticity with voids. The governing equations of generalized thermo-viscoelastic medium with voids are specialized in x-z plane. The plane wave solution of these equations shows the existence of three coupled longitudinal waves and a shear vertical wave in a generalized thermo-viscoelastic medium with voids. For incident plane wave (longitudinal or shear), three coupled longitudinal waves and a shear vertical wave reflect back in the medium. The mechanical boundary conditions at free surface of solid half-space are considered as impedance boundary conditions, in which the shear force tractions are assumed to vary linearly with the tangential displacement components multiplied by the frequency. The impedance corresponds to the constant of proportionality. The appropriate potentials of incident and reflected waves in the half-space will satisfy the required impedance boundary conditions. A non-homogeneous system of four equations in the amplitude ratios of reflected waves is obtained. These amplitude ratios are functions of material parameters, impedance parameter, angle of incidence, thermal relaxation and speeds of plane waves. Using relevant material parameters for medium, the amplitude ratios are computed numerically and plotted against certain ranges of impedance parameter and the angle of incidence.
7
Content available remote Reflection of Plane Waves from Surface of a Generalized Thermo-viscoelastic Porous Solid Half-space with Impedance Boundary Conditions
Singh B.
Computational Methods in Science and Technology
|
2018
|
Vol. 24, No. 4
273--283
EN
A phenomenon of reflection of plane waves from a thermally insulated surface of a solid half-space is studied in the context of Lord-Shulman theory of generalized thermo-viscoelasticity with voids. The governing equations of generalized thermo-viscoelastic medium with voids are specialized in x-z plane. The plane wave solution of these equations shows the existence of three coupled longitudinal waves and a shear vertical wave in a generalized thermo-viscoelastic medium with voids. For incident plane wave (longitudinal or shear), three coupled longitudinal waves and a shear vertical wave reflect back in the medium. The mechanical boundary conditions on the free surface of solid half-space are considered as impedance boundary conditions, in which the shear force tractions are assumed to vary linearly with the tangential displacement components multiplied by the frequency. The impedance corresponds to the constant of proportionality. The appropriate potentials of incident and reflected waves in the half-space will satisfy the required impedance boundary conditions. A non-homogeneous system of four equations in the amplitude ratios of reflected waves is obtained. These amplitude ratios are functions of material parameters, impedance parameter, angle of incidence, thermal relaxation and speeds of plane waves. Using relevant material parameters for medium, the amplitude ratios are computed numerically and plotted against certain ranges of the impedance parameter and the angle of incidence.
8
Content available remote Reflection and Refraction of Plane HarmonicWaves at an Interface Between Elastic Solid and Magneto-thermoelastic Diffusion Solid with Voids
Kumar R., Kansal T.
Computational Methods in Science and Technology
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2017
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Vol. 23, No. 1
43--56
EN
The problem of the reflection and refraction phenomenon due to longitudinal and transverse waves incident obliquely at a plane interface between uniform elastic solid half-space and magneto-thermoelastic diffusive solid half-space with voids has been studied. It is found that the amplitude ratios of various reflected and refracted waves are functions of the angle of incidence and frequency of the incident wave. The amplitude ratios and energy ratios have been computed numerically for a particular model. The variations of energy ratios with angle of incidence are shown graphically.
9
Content available Reflection and transmission at the boundary surface of modified couple stress thermoelastic media
Kumar R., Kumar K.
International Journal of Applied Mechanics and Engineering
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2016
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Vol. 21, no. 1
61--81
EN
In this paper the reflection and transmission at a plane interface in modified couple stress generalized thermoelastic solid half spaces in the context of Loard-Shulman (LS) and Green-Lindsay (GL) theories in welded contact are investigated. Amplitude ratios of various reflected and transmitted waves are obtained due to incidence of a set of coupled longitudinal waves and coupled transverse waves. It is found that the amplitude ratios of various reflected and transmitted waves are functions of the angle of incidence, frequency and are affected by the couple stress properties of the media. Some special cases are deduced from the present formulation.
10
Content available Wave propagation in a micropolar transversely isotropic generalized thermoelastic half-space
Gupta R. R.
International Journal of Applied Mechanics and Engineering
|
2014
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Vol. 19, no. 2
247--257
EN
Rayleigh waves in a half-space exhibiting microplar transversely isotropic generalized thermoelastic properties based on the Lord-Shulman (L-S), Green and Lindsay (G-L) and Coupled thermoelasticty (C-T) theories are discussed. The phase velocity and attenuation coefficient in the previous three different theories have been obtained. A comparison is carried out of the phase velocity, attenuation coefficient and specific loss as calculated from the different theories of generalized thermoelasticity along with the comparison of anisotropy. The amplitudes of displacements, microrotation, stresses and temperature distribution were also obtained. The results obtained and the conclusions drawn are discussed numerically and illustrated graphically. Relevant results of previous investigations are deduced as special cases.
11
Content available Surface wave characteristics in a micropolar transversely isotropic halfspace underlying an inviscid liquid layer
Gupta R. R., Gupta R. R.
International Journal of Applied Mechanics and Engineering
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2014
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Vol. 19, no. 1
49--60
EN
The present investigation deals with the propagation of waves in a micropolar transversely isotropic half space with an overlying inviscid fluid layer. Effects of fluid loading and anisotropy on the phase velocity, attenuation coefficient, specific loss and relative frequency shift. Finally, a numerical solution was carried out for aluminium epoxy material and the computer simulated results for the phase velocity, attenuation coefficient, specific loss and relative frequency shift are presented graphically. A particular case for the propagation of Rayleigh waves in a micropolar transversely isotropic half-space is deduced and dispersion curves are plotted for the same as functions of the wave number. An amplitude of displacements and microrotation together with the path of surface particles are also calculated for the propagation of Rayleigh waves in the latter case.
12
Content available remote Stoneley waves at swelling porous elastic media
Kumar R., Taneja D., Kumar K.
International Journal of Applied Mechanics and Engineering
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2012
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Vol. 17, no. 4
1177-1192
EN
A frequency equation for Stoneley waves at a bonded interface between two swelling porous elastic half spaces [SP/SP] is derived. It is found that Stoneley waves in a swelling porous elastic medium are dispersive in nature. Numerical computations are performed to study the variation of phase velocity and attenuation coefficient with respect to the wave number. Amplitude ratios are obtained and also represented graphically. Some particular cases are also discussed.
13
Content available remote Reflection of transverse and microrotational waves from free surface in micropolar thermodiffusive elastic half-space
Kumar R., Kaushal S., Sharma K. D., Garg S. K.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 1
143-159
EN
The problem of reflection of plane waves in a micropolar thermodiffusive elastic has been investigated in the context of coupled theory. The amplitude ratios of various reflected waves are continuous function of the angle of incidence and material parameters of the medium. A graphical representation of amplitude ratios is presented and the impact of micropolarity and diffusive property of the medium is observed to be significant. Some special cases of interest are deduced.
14
Content available remote Reflection of transverse and microrotational waves from free surface in micropolar thermodiffusion elastic half-space
Kumar R., Kaushal S., Sharma K. D., Garg S. K.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 2
401-417
EN
The problem of reflection of plane waves in a micropolar thermodiffusion elastic is investigated in the context of the coupled theory. The amplitude ratios of various reflected waves are continuous functions of the angle of incidence and material parameters of the medium. A graphical representation of amplitude ratios is presented and the impact of micropolarity and diffusion property of the medium is observed to be significant. Some special cases of interest are deduced from the present article.
15
Content available remote Propagation of waves in a micropolar transversely isotropic generalized thermoelastic half-space
Kumar R., Gupta R. R.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no. 3
671-681
EN
Rayleigh waves in a half-space exhibiting microplar transversely isotropic generalized thermoelastic properties based on the Lord-Shulman (L-S), Green and Lindsay (G-L) and Coupled thermoelasticty (C-T) theories are discussed. The phase velocity and attenuation coefficient in the previous three different theories have been obtained. A comparison is carried out of phase velocity, attenuation coefficient and specific loss as calculated from the different theories of generalized thermoelasticity along with the comparison of anisotropy. The amplitudes of displacements, microrotation, stresses and temperature distribution are also obtained. The results obtained and the conclusions drawn are discussed numerically and illustrated graphically. Relevant results of previous investigations are deduced as special cases.
16
Content available Reflection and transmission of plane waves between two different fluid saturated porous half spaces
Kumar R., Miglani A., Kumar S.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2011
|
Vol. 59, nr 2
227-234
EN
The present study is concerned with the reflection and transmission of plane waves between two different fluid saturated porous half spaces when longitudinal and transversal waves impinge obliquely at the interface. Amplitude ratios of various reflected and transmitted waves are obtained .The variations of amplitude ratios with angle of incidence are depicted graphically. A particular case of reflection at the free surface in fluid saturated porous half spaces has been deduced and discussed. A special case of interest has also been deduced from the present investigation.
17
Content available remote Effects of viscosity and stiffness on wave propagation in micropolar viscoelastic media
Kumar R., Sharma N.
International Journal of Applied Mechanics and Engineering
|
2009
|
Vol. 14, no. 2
415-431
EN
The problem of a reflection and transmission of plane waves at an imperfect interface between two homogeneous, isotropic micropolar viscoelastic half-spaces of different properties is studied. The expressions for the reflection and transmission coefficients which are the ratios of the amplitude of reflected and transmitted waves to the angle of incident wave are obtained and deduced for the normal force stiffness, transverse force stiffness, transverse couple stiffness and perfect bonding. Viscous and stiffness effects on these amplitude ratios with angle of incidence have been shown graphically. Some special cases of interest have been deduced from the present investigation.
18
Content available remote Reflection of longitudinal displacement plane waves from the flat boundary of a solid elastic half-space containing a distribution of void pores
Acharya D. P., Mondal A.
International Journal of Applied Mechanics and Engineering
|
2008
|
Vol. 13, no. 3
609-625
EN
This paper investigates the problem of reflection of longitudinal displacement waves in a medium containing a distribution of void pores. It is observed that three types of waves, traveling at three distinct speeds, may exist in an elastic medium with void pores. The critical frequency has been detected. Amplitude ratios have been presented. It is found that the presence of void pores modulates the wave velocities and amplitude ratios to a considerable extent. Numerical calculations have been made and graphs are drawn to exhibit the role of void pores in the problem under consideration.
19
Content available remote Reflection at the free surface of magneto-thermo-microstretch elastic solid
Kumar R., Rupender R.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2008
|
Vol. 56, nr 3
263-271
EN
The present investigation is concerned with the reflection in thermo-microstretch elastic solid in the presence of a transverse magnetic field, at the boundary surface. The generalized theories of thermoelasticity developed by Lord and Shulman [1](L-S) and Green and Lindsay [2](G-L) theories have been used to investigate the problem. The variations of amplitude ratios with angle of incidence have been shown graphically. It is noticed that the amplitude ratios of the reflected waves are affected by magnetic field, stretch and thermal properties of the medium.
20
Content available remote Propagation of thermoelastic waves at liquid-solid interface in the presence of circular cracks
Singh B.
International Journal of Applied Mechanics and Engineering
|
2007
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Vol. 12, no. 3
799-811
EN
Liquid-solid interface is considered for studying the reflection-refraction phenomenon where a liquid medium is assumed thermally conducting and a solid medium is assumed thermally conducting with circular cracks. The boundary conditions are satisfied to obtain reflection and refraction coefficients. A numerical example is considered to show the effects of circular cracks on the reflection-refraction process.
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