Search results
1 – 10 of 120Mohamed I.A. Othman, Samia Said and Marin Marin
In the present paper, the three-phase-lag (3PHL) model, Green-Naghdi theory without energy dissipation (G-N II) and Green-Naghdi theory with energy dissipation (G-N III) are used…
Abstract
Purpose
In the present paper, the three-phase-lag (3PHL) model, Green-Naghdi theory without energy dissipation (G-N II) and Green-Naghdi theory with energy dissipation (G-N III) are used to study the influence of the gravity field on a two-temperature fiber-reinforced thermoelastic medium.
Design/methodology/approach
The analytical expressions for the displacement components, the force stresses, the thermodynamic temperature and the conductive temperature are obtained in the physical domain by using normal mode analysis.
Findings
The variations of the considered variables with the horizontal distance are illustrated graphically. Some comparisons of the thermo-physical quantities are shown in the figures to study the effect of the gravity, the two-temperature parameter and the reinforcement. Also, the effect of time on the physical fields is observed.
Originality/value
To the best of the author’s knowledge, this model is a novel model of plane waves of two-temperature fiber-reinforced thermoelastic medium, and gravity plays an important role in the wave propagation of the field quantities. It explains that there are significant differences in the field quantities under the G-N II theory, the G-N III theory and the 3PHL model because of the phase-lag of temperature gradient and the phase-lag of heat flux.
Details
Keywords
Samia M. Said, Mohamed I.A. Othman and Mohamed G. Eldemerdash
In the present article, the three-phase-lag (3PHL) model and the Green-Naghdi theory of types II, III with memory-dependent derivative is used to study the effect of rotation on a…
Abstract
Purpose
In the present article, the three-phase-lag (3PHL) model and the Green-Naghdi theory of types II, III with memory-dependent derivative is used to study the effect of rotation on a nonlocal porous thermoelastic medium.
Design/methodology/approach
In this study normal mode analysis is used to obtain analytical expressions of the physical quantities. The numerical results are given and presented graphically when mechanical force is applied.
Findings
The model is illustrated in the context of the Green-Naghdi theory of types II, III and the three-phase lags model. Expressions for the physical quantities are solved by using the normal mode analysis and represented graphically.
Originality/value
Comparisons are made with the results predicted in the absence and presence of the rotation as well as a nonlocal parameter. Also, the comparisons are made with the results of the 3PHL model for different values of time delay.
Details
Keywords
The purpose of this paper is to investigate the effect of a hydrostatic initial stress and the gravity field on a fiber-reinforced thermoelastic medium with an internal heat…
Abstract
Purpose
The purpose of this paper is to investigate the effect of a hydrostatic initial stress and the gravity field on a fiber-reinforced thermoelastic medium with an internal heat source that is moving with a constant speed.
Design/methodology/approach
A general model of the equations of the formulation in the context of the three-phase-lag model and Green-Naghdi theory without energy dissipation.
Findings
The exact expressions for the displacement components, force stresses, and the thermal temperature for the thermal shock problem obtained by using normal mode analysis.
Originality/value
A comparison made between the results of the two models for different values of a hydrostatic initial stress as well as an internal heat source. Comparisons also made with the results of the two models in the absence and presence of the gravity field as well as the reinforcement.
Details
Keywords
The present study discussed wave propagation in a nonlocal generalized thermoelastic half-space with moving an internal heat source under influence of rotation.
Abstract
Purpose
The present study discussed wave propagation in a nonlocal generalized thermoelastic half-space with moving an internal heat source under influence of rotation.
Design/methodology/approach
Normal mode analysis is introduced to obtain the analytical expressions of the physical quantities.
Findings
Numerical results are presented graphically to explore the effects of rotation, the nonlocal parameter, and the time-delay on the physical quantities. It is found that the physical quantities are affected by rotation, the nonlocal parameter, and the time-delay.
Originality/value
The problem is solved based on the classical-coupled theory, the Lord–Shulman theory, and the Green–Lindsay theory with memory-dependent derivative (MDD).
Details
Keywords
However, despite the significant publicity given to the deal by the government, it still falls short of an overarching host government agreement (HGA). The deadline for this has…
Details
DOI: 10.1108/OXAN-DB271030
ISSN: 2633-304X
Keywords
Geographic
Topical
This appears to be yet another signal of her resolve to tame her critics within the government and party, notably among loyalists of former President John Magufuli.
Details
DOI: 10.1108/OXAN-DB266960
ISSN: 2633-304X
Keywords
Geographic
Topical
TANZANIA: Policy shifts will attract guarded optimism
Details
DOI: 10.1108/OXAN-ES260670
ISSN: 2633-304X
Keywords
Geographic
Topical
The purpose of this paper is to investigate the effect of rotation and a magnetic field on the wave propagation in a generalized thermoelastic problem for a medium with an…
Abstract
Purpose
The purpose of this paper is to investigate the effect of rotation and a magnetic field on the wave propagation in a generalized thermoelastic problem for a medium with an internal heat source that is moving with a constant speed.
Design/methodology/approach
The formulation is applied to a generalized thermoelastic problem based on the three-phase-lag model and Green-Naghdi theory without energy dissipation. The medium is a homogeneous isotropic thermoelastic in the half-space.
Findings
The exact expressions of the displacement components, temperature, and stress components are obtained by using normal mode analysis.
Originality/value
Comparisons are made with the results predicted by the two models in the absence and presence of a magnetic field as well as a rotation. A comparison also is made with the results predicted by the two models for two different values of an internal heat source.
Details
Keywords
Mohamed Ibrahim Othman, Samia M. Said and N. Sarker
The purpose of this paper is to investigate the influences of fractional order, hydrostatic initial stress and gravity field on the plane waves in a linearly fiber-reinforced…
Abstract
Purpose
The purpose of this paper is to investigate the influences of fractional order, hydrostatic initial stress and gravity field on the plane waves in a linearly fiber-reinforced isotropic thermoelastic medium.
Design/methodology/approach
The problem has been solved analytically and numerically by using the normal mode analysis.
Findings
Numerical results for the temperature, the displacement components and the stress components are presented graphically and analyzed the results. The graphical results indicate that the effect of fractional order, hydrostatic initial stress and gravity field on the plane waves in the fiber-reinforced thermoelastic medium are very pronounced. Comparisons are made with the results in the absence and presence of hydrostatic initial stress and gravity field.
Originality/value
In the present work, the authors shall formulate a fiber-reinforced two-dimensional problem under the effect of fractional order, hydrostatic initial stress, and gravity field. The normal mode analysis is used to obtain the exact expression for the temperature, displacement components, and stress components. A comparison is also made between the three theories in the absence and presence of gravity field. Such problems are very important in many dynamical systems.
Details
Keywords
The dual-phase-lag (DPL) model and Lord-Shulman theory with one relaxation time are applied to study the effect of the gravity field, the magnetic field, and the hydrostatic…
Abstract
Purpose
The dual-phase-lag (DPL) model and Lord-Shulman theory with one relaxation time are applied to study the effect of the gravity field, the magnetic field, and the hydrostatic initial stress on the wave propagation in a two-temperature generalized thermoelastic problem for a medium with an internal heat source that is moving with a constant speed. The paper aims to discuss this issue.
Design/methodology/approach
The exact expressions of the considered variables are obtained by using normal mode analysis.
Findings
Numerical results for the field quantities are given in the physical domain and illustrated graphically in the absence and presence of the gravity field as well as the magnetic field. Comparisons are made between the results of the two different models with and without temperature dependent properties and for two different values of the hydrostatic initial stress. A comparison is also made between the results of the two different models for two different values of the time.
Originality/value
In the present work, the author shall formulate a two-temperature generalized magneto-thermoelastic problem for a medium with temperature dependent properties and with an internal heat source that is moving with a constant speed under the influence of a gravity field and a hydrostatic initial stress. Normal mode analysis is used to obtain the exact expressions for the displacement components, thermodynamic temperature, conductive temperature, and stress components. A comparison is carried out between the considered variables as calculated from the generalized thermoelasticity based on the DPL model and the L-S theory in the absence and presence of a magnetic field as well as a gravity field. Comparisons are also made between the results of the two theories with and without temperature dependent properties and for two different values of hydrostatic initial stress. A comparison is also made between the results of the two different models for two different values of the time.
Details