Effect of gravity on generalized thermoelastic diffusion due to laser pulse using dual-phase-lag model

2018 ◽  
Vol 14 (3) ◽  
pp. 457-481 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Ebtesam E.M. Eraki

Purpose The purpose of this paper is to obtain a general solution to the field equations of generalized thermo-diffusion in an infinite thermoelastic body under the effect of gravity in the context of the dual-phase-lag (DPL) model. The half space is considered made of an isotropic homogeneous thermoelastic material. The boundary plane surface is heated by a non-Gaussian laser beam. Design/methodology/approach An exact solution to the problem is obtained using the normal mode analysis. Findings The derived expressions are computed numerically for copper and the results are presented in graphical form. Originality/value Comparisons are made with the results predicted by Lord-Shulman theory and DPL model for different values of time and in the presence and absence of gravity as well as diffusion.

Author(s):  
Mohamed I.A. Othman ◽  
Sudip Mondal

Purpose The purpose of this paper is to introduce the phase-lag models (Lord-Shulman, dual-phase-lag and three-phase-lag) to study the effect of memory-dependent derivative and the influence of thermal loading due to laser pulse on the wave propagation of generalized micropolar thermoelasticity. The bounding plane surface is heated by a non-Gaussian laser beam with a pulse duration of 10 nanoseconds. Design/methodology/approach The normal mode analysis technique is used to obtain the exact expressions for the displacement components, the force stresses, the temperature, the couple stresses and the micro-rotation. Comparisons are made with the results predicted by three theories of the authors’ interest. Excellent predictive capability is demonstrated at a different time also. Findings The effect of memory-dependent derivative and the heat laser pulse on the displacement, the temperature distribution, the components of stress, the couple stress and the microrotation vector have been depicted graphically. Research limitations/implications Some particular cases are also deduced from the present investigation. Originality/value The numerical results are presented graphically and are compared with different three theories for both in the presence and absence of memory-dependent effect and with the results predicted under three theories for two different values of the time.


2014 ◽  
Vol 10 (3) ◽  
pp. 328-345 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
W.M. Hasona ◽  
Elsayed M. Abd-Elaziz

Purpose – The purpose of this paper is to introduce the coupled theory, Lord-Shulman theory with one relaxation time and Green-Lindsay theory with two relaxation times to study the influence of rotation on generalized micropolar thermoelasticity subject to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam with pulse duration of 8 ps. Design/methodology/approach – The problem has been solved numerically by using the normal mode analysis. Findings – The thermal shock problem is studied to obtain the exact expressions for the displacement components, force stresses, temperature, couple stresses and micro-rotation. The distributions of the considered variables are illustrated graphically. Comparisons are made with the results predicted by three theories in the presence and absence of laser pulse and for different values of time. Originality/value – Generalized micropolar thermoelastic solid.


2014 ◽  
Vol 92 (11) ◽  
pp. 1359-1371 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Magda E.M. Zidan ◽  
Mohamed I.M. Hilal

This investigation deals with the rotation of magneto-thermoelastic solid with voids subjected to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam. The entire porous medium is rotated with a uniform angular velocity. The problem is studied in the context of Green–Naghdi (GN) theory of types II and III, with the effect of rotation, magnetic field, thermal loading and voids. Normal mode analysis is used to solve the physical problem to obtain the exact expressions for the displacement components, stresses, temperature distribution, and change in the volume fraction field, which have been shown graphically by comparison between two types of GN theory (types II and III) in the presence and the absence of rotation and magnetic field and for two values of time on thermoelastic material with voids.


2018 ◽  
Vol 14 (1) ◽  
pp. 102-124 ◽  
Author(s):  
Sunita Deswal ◽  
Baljit Singh Punia ◽  
Kapil Kumar Kalkal

Purpose The dual-phase-lag (DPL) model is applied to study the effect of the gravity field and micropolarity on the wave propagation in a two-temperature generalized thermoelastic problem for a medium. 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 to show the effect of angle of inclination. Comparisons of the physical quantities are also shown in figure to study the effect of gravity and two-temperature parameter. Originality/value This paper is concerned with the analysis of transient wave phenomena in a micropolar thermoelastic half-space subjected to inclined load. The governing equations are formulated in the context of two-temperature generalized thermoelasticity theory with DPLs. A medium is assumed to be initially quiescent and under the effect of gravity. An analytical solution of the problem is obtained by employing normal mode analysis. Numerical estimates of displacement, stresses and temperatures are computed for magnesium crystal-like material and are illustrated graphically. Comparisons of the physical quantities are shown in figures to study the effects of gravity, two-temperature parameter and angle of inclination. Some particular cases of interest have also been inferred from the present problem.


Author(s):  
Amnah M. Alharbi ◽  
Mohamed I. A. Othman ◽  
Elsayed M. Abd-Elaziz

This study considers a thermoelastic micro-elongated solid which is being heated by a laser pulse in order to investigate the corresponding impact of thermal loading and magnetic field. A laser beam that is non-Gaussian in nature is used to heat the surface of the bounded plane with a pulse duration [Formula: see text][Formula: see text]ps. The dual-phase-lag (DPL) model is considered to develop a better understanding of the problem. Also, the problems are solved using normal mode analysis as well as it helps in attaining the appropriate expressions for micro-rotation, components of displacement, the force stress, couple stress, concentration field, the temperature distribution the scalar micro-elongated function, and the micro-stress. The results obtained from the thermal variations are validated by comparing them to Coupled Theory (CT) of thermo-elasticity, Lord and Shulman (L–S) theory, and the DPL model. The graphical illustration of these comparisons has been presented as it helps in exploring the impacts of the laser pulse at two different times and the magnetic field parameter. The investigation also helped deduce some specific cases of interest.


Author(s):  
Amnah M. Alharbi ◽  
Mohamed I. A. Othman ◽  
Elsayed M. Abd-Elaziz

The paper presents the analytical solutions for a generalized thermoelastic medium consisting of microtemperatures and voids subjected to a laser pulse loading the medium thermally. The 0.02 ps pulse duration of the non-Gaussian laser beam is apt for heating a homogenous isotropic elastic half-space. A method called the normal mode analysis is employed to evaluate numerically the effects of various variables such as the micro-temperature vector, variation in the fraction field of the volume, first heat flux moment tensor, temperature distribution on the stresses and displacement components of the medium. In addition, the graphical illustration of the physical response of the medium has been presented in the presence and absence of void parameters, as well as in the presence of laser pulse with two different acting periods.


2016 ◽  
Vol 12 (3) ◽  
pp. 478-494
Author(s):  
Rajneesh Kumar ◽  
Shaloo Devi ◽  
Veena Sharma

Purpose The purpose of this paper is to investigate the two-dimensional axisymmetric problem in a homogeneous, isotropic modified couple stress thermoelastic diffusion (TD) medium in the context of dual-phase-lag model. Design/methodology/approach The Laplace and Hankel transforms have been applied to find the general solution to the field equations. The components of displacement, stresses, temperature change and chemical potential are obtained in the transformed domain. The resulting quantities are obtained in the physical domain by using numerical inversion technique. Findings The components of normal stress, tangential stress, tangential couple stress, temperature change and chemical potential are obtained numerically and depicted graphically to see the effect of dual-phase-lag diffusion (DLD), dual-phase-lag heat transfer (DLT) and TD models in the absence and presence of couple stress parameter. Originality/value Comparisons are made in the absence and presence of couple stress DLD, DLT and TD models.


2017 ◽  
Vol 14 (03) ◽  
pp. 1750030 ◽  
Author(s):  
Abhik Sur ◽  
M. Kanoria

The present paper deals with the problem of thermoelastic interactions in a homogeneous, isotropic three-dimensional medium whose surface suffers a time dependent thermal loading. The problem is treated on the basis of three-phase-lag model and dual-phase-lag model with two temperatures. The medium is assumed to be unstressed initially and has uniform temperature. Normal mode analysis technique is employed onto the non-dimensional field equations to derive the exact expressions for displacement component, conductive temperature, thermodynamic temperature, stress and strain. The problem is illustrated by computing the numerical values of the field variables for a copper material. Finally, all the physical fields are represented graphically to analyze the difference between the two models. The effect of the two temperature parameter is also discussed.


Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Muhammad Rafiq ◽  
Baljeet Singh ◽  
Samreen Arifa ◽  
Muhammad Nazeer ◽  
Muhammad Usman ◽  
...  

Abstract The current work analyzes the transmission behavior of plane harmonic waves in an isotropic medium. The observation is made for homogeneous type solid in the context of generalized dual phase lag model of thermoelasticity. Concept micro-temperature, where the microelements have different temperatures has also been considered. The basic focus of thework is to predict the influence of initially applied magnetic field on plane waves through the elastic solid. We have made an attempt to find exact solution of the problem using an analytical technique of a normal mode analysis method. The theoretical results are obtained for a generalized solid in order to test the numerical calculation of a magnesium crystal. It is found that the magnetic field reduces the strength of the attenuation factor.


2014 ◽  
Vol 92 (9) ◽  
pp. 1002-1015 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
W.M. Hasona ◽  
Elsayed M. Abd-Elaziz

In the present paper, we introduce the coupled theory, Lord–Schulman theory, and Green–Lindsay theory to study the influences of a magnetic field and rotation on a two-dimensional problem of fiber-reinforced thermoelasticity subject to thermal loading by a laser pulse. The material is a homogeneous isotropic elastic half-space and is heated by a non-Gaussian laser beam with pulse duration of 8 ps. The method applied here is to use normal mode analysis to solve a thermal shock problem. Deformation of a body depends on the nature of the force applied as well as the type of boundary conditions. Numerical results for the temperature, displacement, and thermal stress components are given and illustrated graphically in the absence and the presence of the magnetic field, rotation, reinforcement, and for two different values of time.


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