Effects of Hall current in a transversely isotropic magnetothermoelastic with and without energy dissipation due to normal force

Rajneesh Kumar,Nidhi Sharma,Parveen Lata 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.57 No.1

This investigation is concerned with the disturbances in a homogeneous transversely isotropic thermoelastic rotating medium with two temperature, in the presence of the combined effects of Hall currents and magnetic field due to normal force of ramp type. The formulation is applied to the thermoelasticity theories developed by Green-Naghdi Theories of Type-II and Type-III. Laplace and Fourier transform technique is applied to solve the problem. The analytical expressions of displacements, stress components, temperature change and current density components are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results are depicted graphically to show the effects of Hall current and anisotropy on the resulting quantities. Some special cases are also deduced from the present investigation.

Representation of fundamental solution and vibration of waves in photothermoelastic under MGTE model

Rajneesh Kumar,Nidhi Sharma,Supriya Chopra,Anil K. Vashishth Techno-Press 2023 Ocean systems engineering Vol.13 No.2

In this paper, Moore-Gibson-Thompson theory of thermoelasticity is considered to investigate the fundamental solution and vibration of plane wave in an isotropic photothermoelastic solid. The governing equations are made dimensionless for further investigation. The dimensionless equations are expressed in terms of elementary functions by assuming time harmonic variation of the field variables (displacement, temperature distribution and carrier density distribution). Fundamental solutions are constructed for the system of equations for steady oscillation. Also some preliminary properties of the solution are explored. In the second part, the vibration of plane waves are examined by expressing the governing equation for two dimensional case. It is found that for the non-trivial solution of the equation yield that there exist three longitudinal waves which advance with the distinct speed, and one transverse wave which is free from thermal and carrier density response. The impact of various models (i)Moore-Gibson-Thomson thermoelastic (MGTE)(2019), (ii) Lord and Shulman's (LS)(1967) , (iii) Green and Naghdi type-II(GN-II)(1993) and (iv) Green and Naghdi type-III(GN-III)(1992) on the attributes of waves i.e., phase velocity, attenuation coefficient, specific loss and penetration depth are elaborated by plotting various figures of physical quantities. Various particular cases of interest are also deduced from the present investigations. The results obtained can be used to delineate various semiconductor elements during the coupled thermal, plasma and elastic wave and also find the application in the material and engineering sciences.

Dynamical behavior of generalized thermoelastic diffusion with two relaxation times in frequency domain

Sharma, Nidhi,Kumar, Rajneesh,Ram, Paras Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

A general solution to the field equations of homogeneous isotropic generalized thermoelastic diffusion with two relaxation times (Green and Lindsay theory) has been obtained using the Fourier transform. Assuming the disturbances to be harmonically time.dependent, the transformed solution is obtained in the frequency domain. The application of a time harmonic concentrated and distributed loads have been considered to show the utility of the solution obtained. The transformed components of displacement, stress, temperature distribution and chemical potential distribution are inverted numerically, using a numerical inversion technique. Effect of diffusion on the resulting expressions have been depicted graphically for Green and Lindsay (G-L) and coupled (C-T) theories of thermoelasticity.

Photothermoelastic interactions under Moore-Gibson-Thompson thermoelasticity

Kumar, Rajneesh,Sharma, Nidhi,Chopra, Supriya Techno-Press 2022 Coupled systems mechanics Vol.11 No.5

In the present work, a new photothermoelastic model based on Moore-Gibson-Thompson theory has been constructed. The governing equationsfor orthotropic photothermoelastic plate are simplified for two-dimension model. Laplace and Fourier transforms are employed after converting the system of equations into dimensionless form. The problem is examined due to various specified sources. Moving normal force, ramp type thermal source and carrier density periodic loading are taken to explore the application of the assumed model. Various field quantities like displacements, stresses, temperature distribution and carrier density distribution are obtained in the transformed domain. The problem is validated by numerical computation for a given material and numerical obtained results are depicted in form of graphs to show the impact of varioustheories of thermoelasticity along with impact of moving velocity, ramp type and periodic loading parameters. Some special cases are also explored. The results obtained in this paper can be used to design various semiconductor elements during the coupled thermal, plasma and elastic wave and otherfieldsin thematerialscience, physical engineering.

Rayleigh waves in anisotropic magnetothermoelastic medium

Kumar, Rajneesh,Sharma, Nidhi,Lata, Parveen,Abo-Dahab, S.M. Techno-Press 2017 Coupled systems mechanics Vol.6 No.3

The present paper is concerned with the investigation of Rayleigh waves in a homogeneous transversely isotropic magnetothermoelastic medium with two temperature, in the presence of Hall current and rotation. The formulation is applied to the thermoelasticity theories developed by Green-Naghdi theories of Type-II and Type-III. Secular equations are derived mathematically at the stress free and thermally insulated boundaries. The values of Determinant of secular equations, phase velocity and Attenuation coefficient with respect to wave number are computed numerically. Cobalt material has been chosen for transversely isotropic medium and magnesium material is chosen for isotropic solid. The effects of rotation, magnetic field and phase velocity on the resulting quantities and on particular case of isotropic solid are depicted graphically. Some special cases are also deduced from the present investigation.

Effect of fractional order on energy ratios at the boundary surface of elastic-piezothermoelastic media

Kumar, Rajneesh,Sharma, Poonam Techno-Press 2017 Coupled systems mechanics Vol.6 No.2

In the present investigation reflection and transmission of plane waves at an elastic half space and piezothermoelastic solid half space with fractional order derivative is discussed. The piezothermoelastic solid half space is assumed to have 6 mm type symmetry and assumed to be loaded with an elastic half space. It is found that the amplitude ratios of various reflected and refracted waves are functions of angle of incidence, frequency of incident wave and are influenced by the piezothermoelastic properties of media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios are computed numerically using amplitude ratios for a particular model of graphite and Cadmium Selenide (CdSe). The variations of energy ratios with angle of incidence are shown graphically. The conservation of energy across the interface is verified. Some cases of interest are also deduced from the present investigation.

Effect of NTT on Performance of AODV in a Grid Topology-Based Wireless Ad Hoc Network

Saurabh Sharma,Alok Singh,Rajneesh Kumar Srivastava 한국정보과학회 2022 Journal of Computing Science and Engineering Vol.16 No.3

Routing in wireless ad hoc networks that enable nodes, acting as routers also, to find the best path between source and destination nodes, taking into account cost, is a very challenging task. In the present work, an investigation of performance of AODV routing protocol in a grid topology based ad hoc network by varying the value of node traversal time (NTT) and taking into account absence and presence of Hello messages is reported. A set of metrics, including Average End-to-End Delay, Packet Delivery Ratio, Throughput, Routing Overhead, Route Error Overhead, Normalized Routing Load, Average Hop Count, and Total Number of Received Data Packets, has been used to assess the performance of AODV in the grid network. Performance of AODV routing protocol varies in the value of NTT. Throughput in grid topology, by and large, is observed to decrease with an increase in NTT. However, explicit relations between certain metrics with NTT as well as simulation time could not be traced due to intricacies involved in the combination of states of various links and flows in the grid topology. To have better insights, grid topologies of two, three, and four rows are planned to be investigated in the future.

Effect of fractional order on energy ratios at the boundary surface of elastic-piezothermoelastic media

Kumar, Rajneesh,Sharma, Poonam 테크노프레스 2016 Multiscale and multiphysics mechanics Vol.1 No.4

In the present investigation reflection and transmission of plane waves at an elastic half space and piezothermoelastic solid half space with fractional order derivative is discussed. The piezothermoelastic solid half space is assumed to have 6 mm type symmetry and assumed to be loaded with an elastic half space. It is found that the amplitude ratios of various reflected and refracted waves are functions of angle of incidence, frequency of incident wave and are influenced by the piezothermoelastic properties of media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios are computed numerically using amplitude ratios for a particular model of graphite and Cadmium Selenide (CdSe). The variations of energy ratios with angle of incidence are shown graphically. The conservation of energy across the interface is verified. Some cases of interest are also deduced from the present investigation.

Dynamical behavior of generalized thermoelastic diffusion with two relaxation times in frequency domain

Nidhi Sharma,Rajneesh Kumar,Paras Ram 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

A general solution to the field equations of homogeneous isotropic generalized thermoelastic diffusion with two relaxation times (Green and Lindsay theory) has been obtained using the Fourier transform. Assuming the disturbances to be harmonically time.dependent, the transformed solution is obtained in the frequency domain. The application of a time harmonic concentrated and distributed loads have been considered to show the utility of the solution obtained. The transformed components of displacement, stress, temperature distribution and chemical potential distribution are inverted numerically, using a numerical inversion technique. Effect of diffusion on the resulting expressions have been depicted graphically for Green and Lindsay (G-L) and coupled (C-T) theories of thermoelasticity.

Effects of stiffness on reflection and transmission of micropolar thermoelastic waves at the interface between an elastic and micropolar generalized thermoelastic solid

Kumar, Rajneesh,Sharma, Nidhi,Ram, Paras Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.2

The reflection and transmission of micropolar thermoelastic plane waves at the interface between an elastic solid and micropolar generalized thermoelastic solid is discussed. The interface boundary conditions obtained contain interface stiffness (normal stiffness and transverse stiffness). The expressions for the reflection and transmission coefficients which are the ratios of the amplitudes of reflected and transmitted waves to the amplitude of incident waves are obtained for normal force stiffness, transverse force stiffness and welded contact. Numerical calculations have been performed for amplitude ratios of various reflected and transmitted waves. The variations of amplitude ratios with angle of incident wave have been depicted graphically. It is found that the amplitude ratios of reflected and transmitted waves are affected by the stiffness, micropolarity and thermal distribution of the media.